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  • 1.
    Agrawal, Mukta
    et al.
    Rungta Coll Pharmaceut Sci & Res, Kohka Kurud Rd, Bhilai , Chhattisgarh, India..
    Ajazuddin, A
    Rungta College of Pharmaceutical Sciences and Research, Kohka-Kurud Road, Bhilai 490024, Chhattisgarh, India.
    Tripathi, Dulal K.
    Rungta Coll Pharmaceut Sci & Res, Kohka Kurud Rd, Bhilai 490024, Chhattisgarh, India..
    Saraf, Swarnlata
    Pt Ravishankar Shukla Univ, Univ Inst Pharm, Raipur 492010, Chhattisgarh, India..
    Saraf, Shailendra
    Pt Ravishankar Shukla Univ, Univ Inst Pharm, Raipur 492010, Chhattisgarh, India..
    Antimisiaris, Sophia G.
    Univ Patras, Dept Pharm, Lab Pharmaceut Technol, Rion 26510, Greece.;Inst Chem Engn, FORTH ICE HT, Patras 25104, Greece..
    Mourtas, Spyridon
    Univ Patras, Dept Pharm, Lab Pharmaceut Technol, Rion 26510, Greece..
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Alexander, Amit
    Rungta Coll Pharmaceut Sci & Res, Kohka Kurud Rd, Bhilai 490024, Chhattisgarh, India..
    Recent advancements in liposomes targeting strategies to cross blood-brain barrier (BBB) for the treatment of Alzheimer's disease2017In: Journal of Controlled Release, ISSN 0168-3659, E-ISSN 1873-4995, Vol. 260, p. 61-77Article, review/survey (Refereed)
    Abstract [en]

    In this modern era, with the help of various advanced technologies, medical science has overcome most of the health-related issues successfully. Though, some diseases still remain unresolved due to various physiological barriers. One such condition is Alzheimer; a neurodegenerative disorder characterized by progressive memory impairment, behavioral abnormalities, mood swing and disturbed routine activities of the person suffering from. It is well known to all that the brain is entirely covered by a protective layer commonly known as blood brain barrier (BBB) which is responsible to maintain the homeostasis of brain by restricting the entry of toxic substances, drug molecules, various proteins and peptides, small hydrophilic molecules, large lipophilic substances and so many other peripheral components to protect the brain from any harmful stimuli. This functionally essential structure creates a major hurdle for delivery of any drug into the brain. Still, there are some provisions on BBB which facilitate the entry of useful substances in the brain via specific mechanisms like passive diffusion, receptor-mediated transcytosis, carrier-mediated transcytosis etc. Another important factor for drug transport is the selection of a suitable drug delivery systems like, liposome, which is a novel drug carrier system offering a potential approach to resolving this problem. Its unique phospholipid bilayer structure (similar to physiological membrane) had made it more compatible with the lipoidal layer of BBB and helps the drug to enter the brain. The present review work focused on various surface modifications with functional ligand (like lactoferrin, transferrin etc.) and carrier molecules (such as glutathione, glucose etc.) on the liposomal structure to enhance its brain targeting ability towards the successful treatment of Alzheimer disease.

  • 2.
    Alassaad, Anna
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical pharmacogenomics and osteoporosis.
    Bertilsson, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, UCR-Uppsala Clinical Research Center.
    Gillespie, Ulrika
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Sundström, Johan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, UCR-Uppsala Clinical Research Center. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Cardiology.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Melhus, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical pharmacogenomics and osteoporosis.
    The effects of pharmacist intervention on emergency department visits in patients 80 years and older: subgroup analyses by number of prescribed drugs and appropriate prescribing2014In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 9, no 11, p. e111797-Article in journal (Refereed)
    Abstract [en]

    Background: Clinical pharmacist interventions have been shown to have positive effect on occurrence of drug-related issues as well as on clinical outcomes. However, evidence about which patients benefiting most from the interventions is limited. We aimed to explore whether pharmacist intervention is equally effective in preventing emergency department (ED) visits in patients with few or many prescribed drugs and in those with different levels of inappropriate prescribing. Methods: Patient and outcome data from a randomized controlled trial exploring the clinical effects of a ward-based pharmacist intervention in patients, 80 years and older, were used. The patients were divided into subgroups according to the number of prescribed drugs (< 5 or >= 5 drugs) and the level of inappropriate prescribing [using the Screening Tool Of Older People's potentially inappropriate Prescriptions (STOPP) and the Screening Tool to Alert doctors to Right Treatment (START) with a score of >= 2 (STOPP) and >= 1 (START) as cutoff points]. The effect of the intervention on the number of times the different subgroups visited the ED was analyzed. Results: The pharmacist intervention was more effective with respect to the number of subsequent ED visits in patients taking < 5 drugs on admission than in those taking >= 5 drugs. The rate ratio (RR) for a subsequent ED visit was 0.22 [95% confidence interval (CI) 0.09-0.52] for,5 drugs and 0.70 (95% CI 0.47-1.04) for >= 5 drugs (p = 0.02 for the interaction). The effect of intervention did not differ between patients with high or low STOPP or START scores. Conclusion: In this exploratory study, the pharmacist intervention appeared to be more effective in preventing visits to the ED for patients who were taking fewer drugs before the intervention. Our analysis of STOPP and START scores indicated that the level of inappropriate prescribing on admission had no effect on the outcomes of intervention with respect to ED visits.

  • 3.
    Alassaad, Anna
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical pharmacogenomics and osteoporosis.
    Gillespie, Ulrika
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences, Division of Pharmacokinetics and Drug Therapy.
    Bertilsson, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, UCR-Uppsala Clinical Research Center.
    Melhus, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical pharmacogenomics and osteoporosis.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences, Division of Pharmacokinetics and Drug Therapy.
    Prescription and transcription errors in multidose-dispensed medications on discharge from hospital: an observationaland interventional study2013In: Journal of Evaluation In Clinical Practice, ISSN 1356-1294, E-ISSN 1365-2753, Vol. 19, no 1, p. 185-191Article in journal (Refereed)
    Abstract [en]

    Background 

    Medication errors frequently occur when patients are transferred between health care settings. The main objective of this study was to investigate the frequency, type and severity of prescribing and transcribing errors for drugs dispensed in multidose plastic packs when patients are discharged from the hospital. The secondary objective was to correct identified errors and suggest measures to promote safe prescribing.

    Methods 

    The drugs on the patients' multidose drug dispensing (MDD) order sheets and the medication administration records were reconciled prior to the MDD orders being sent to the pharmacy for dispensing. Discrepancies were recorded and the prescribing physician was notified and given the opportunity to change the order. Discrepancies categorized as unintentional and related to the discharge process were subject to further analysis.

    Results 

    Seventy-two (25%) of the 290 reviewed MDD orders had at least one discharge error. In total, 120 discharge errors were identified, of which 49 (41%) were assessed as being of moderate and three (3%) of major severity. Orders with a higher number of medications and orders from the orthopaedic wards had a significantly higher error rate.

    Conclusion 

    The main purpose of the MDD system is to increase patient safety by reducing medication errors. However, this study shows that prescribing and transcribing errors frequently occur when patients are hospitalized. Because the population enrolled in the MDD system is an elderly, physically vulnerable group with a high number of prescribed drugs, preventive measures to ensure safe prescribing of MDD drugs are warranted.

  • 4.
    Alassaad, Anna
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical pharmacogenomics and osteoporosis.
    Melhus, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical pharmacogenomics and osteoporosis.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Bertilsson, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, UCR-Uppsala Clinical Research Center.
    Gillespie, Ulrika
    Uppsala University Hospital, Uppsala, Sweden.
    Sundström, Johan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, UCR-Uppsala Clinical Research Center. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Cardiology.
    A tool for prediction of risk of rehospitalisation and mortality in the hospitalised elderly: secondary analysis of clinical trial data2015In: BMJ Open, ISSN 2044-6055, E-ISSN 2044-6055, Vol. 5, no 2, article id e007259Article in journal (Refereed)
    Abstract [en]

    Objectives: To construct and internally validate a risk score, the '80+ score', for revisits to hospital and mortality for older patients, incorporating aspects of pharmacotherapy. Our secondary aim was to compare the discriminatory ability of the score with that of three validated tools for measuring inappropriate prescribing: Screening Tool of Older Person's Prescriptions (STOPP), Screening Tool to Alert doctors to Right Treatment (START) and Medication Appropriateness Index (MAI). Setting: Two acute internal medicine wards at Uppsala University hospital. Patient data were used from a randomised controlled trial investigating the effects of a comprehensive clinical pharmacist intervention. Participants: Data from 368 patients, aged 80 years and older, admitted to one of the study wards. Primary outcome measure: Time to rehospitalisation or death during the year after discharge from hospital. Candidate variables were selected among a large number of clinical and drug-specific variables. After a selection process, a score for risk estimation was constructed. The 80+ score was internally validated, and the discriminatory ability of the score and of STOPP, START and MAI was assessed using C-statistics. Results: Seven variables were selected. Impaired renal function, pulmonary disease, malignant disease, living in a nursing home, being prescribed an opioid or being prescribed a drug for peptic ulcer or gastroesophageal reflux disease were associated with an increased risk, while being prescribed an antidepressant drug (tricyclic antidepressants not included) was linked to a lower risk of the outcome. These variables made up the components of the 80+ score. The C-statistics were 0.71 (80+), 0.57 (STOPP), 0.54 (START) and 0.63 (MAI). Conclusions: We developed and internally validated a score for prediction of risk of rehospitalisation and mortality in hospitalised older people. The score discriminated risk better than available tools for inappropriate prescribing. Pending external validation, this score can aid in clinical identification of high-risk patients and targeting of interventions.

  • 5.
    Alenius, Malin
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Hartvig, Per
    Lindström, Leif
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Psychiatry, Ulleråker, University Hospital.
    Knowledge and insight in relation to functional remission in patients with long-term psychotic disorders2010In: Social Psychiatry and Psychiatric Epidemiology, ISSN 0933-7954, E-ISSN 1433-9285, Vol. 45, no 5, p. 523-529Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Patients with psychotic symptoms often respond poorly to treatment. Outcomes can be affected by biological, physiological and psychological factors according to the vulnerability-stress model. The patient's coping strategies and beliefs have been correlated with outcomes. OBJECTIVES: To investigate the knowledge and insight in relation to treatment response. METHODS: A naturalistic study was performed using patient interviews and information gathered from patient drug charts. Apart from the rating scales used for classification of treatment response (CANSEPT method), the SPKS knowledge of illness and drugs rating scale was utilized. RESULTS: In the group of patients in functional remission (FR; n = 38), 37% had insight into their illness as compared to 10% among those not in functional remission (non-FR; n = 78; P < 0.01). As much as 23% of the non-FR group had no strategy for responding to warning signs versus 8% in the FR group (P < 0.05). CONCLUSIONS: Better treatment outcomes appear to be associated with better insight into illness, higher knowledge of warning signs and better coping strategies.

  • 6.
    Alenius, Malin
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Hartvig Honoré, Per
    Lindström, Leif
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Psychiatry, Ulleråker, University Hospital.
    Hammarlund-Udenaes, Margareta
    Current and retrospective antipsychotic drug use in relation to treatment response in a naturalistic setting of psychotic patients2009Article in journal (Refereed)
  • 7.
    Bengtsson, Jörgen
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences, Division of Pharmacokinetics and Drug Therapy.
    Boström, Emma
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences, Division of Pharmacokinetics and Drug Therapy.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences, Division of Pharmacokinetics and Drug Therapy.
    The use of a deuterated calibrator for in vivo recovery estimations in microdialysis studies2008In: Journal of Pharmaceutical Sciences, ISSN 0022-3549, E-ISSN 1520-6017, Vol. 97, no 8, p. 3433-3441Article in journal (Refereed)
    Abstract [en]

    One of the crucial issues in quantitative microdialysis is the reliability of recovery estimates to correctly estimate unbound drug tissue concentrations. If a deuterated calibrator is used for retrodialysis, the calibrator has the same properties as the study drug. However, recovery of the calibrator may be affected by the presence of the drug in the tissues. The aim of this study was to investigate the recovery of deuterated morphine with time in the absence and presence of morphine in rat tissues. Microdialysis probes were placed in the brain and blood of eight rats. Ringer's solution containing D3-morphine was perfused throughout the study and recovery was estimated. After a stabilization period of 3 h, an exponential infusion of morphine was administered over 4 h. The presence of morphine did not affect the recovery of D3-morphine from brain or blood. The average recovery values (SD) were 0.145 (0.039) and 0.131 (0.048) during the stabilization and infusion periods, respectively, for the brain probe and 0.792 (0.055) and 0.790 (0.084), respectively, for the blood probe. The recovery of deuterated morphine was stable over time in the brain and in blood, and was not affected by the presence of pharmacologically concentrations of morphine.

  • 8.
    Bengtsson, Jörgen
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Ederoth, P
    Ley, D
    Hansson, S
    Amer-Wåhlin, I
    Hellström-Westas, Lena
    Marsál, K
    Nordström, C-H
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    The influence of age on the distribution of morphine and morphine-3-glucuronide across the blood-brain barrier in sheep2009In: British Journal of Pharmacology, ISSN 0007-1188, E-ISSN 1476-5381, Vol. 157, no 6, p. 1085-1096Article in journal (Refereed)
    Abstract [en]

    Background and purpose

     The effect of age on the distribution of morphine and morphine-3-glucuronide (M3G) across the blood-brain barrier (BBB) was studied in a sheep model utilizing intracerebral microdialysis. The effect of neonatal asphyxia on brain drug distribution was also studied.

    Experimental approach

     Microdialysis probes were inserted into the cortex, striatum and blood of 11 lambs (127 gestation days) and six ewes. Morphine, 1 mg.kg(-1), was intravenously administered as a 10 min constant infusion. Microdialysis and blood samples were collected for up to 360 min and analysed using liquid chromatography-tandem mass spectrometry. The half-life, clearance, volume of distribution, unbound drug brain : blood distribution ratio (K(p,uu)) and unbound drug volume of distribution in brain (V(u,brain)) were estimated.

     Key results

     Morphine K(p,uu) was 1.19 and 1.89 for the sheep and premature lambs, respectively, indicating that active influx into the brain decreases with age. Induced asphyxia did not affect transport of morphine or M3G across the BBB. Morphine V(u,brain) measurements were higher in sheep than in premature lambs. The M3G K(p,uu) values were 0.27 and 0.17 in sheep and premature lambs, indicating a net efflux from the brain in both groups.

    Conclusions and implications

     The morphine K(p,uu) was above unity, indicating active transport into the brain; influx was significantly higher in premature lambs than in adult sheep. These results in sheep differ from those in humans, rats, mice and pigs where a net efflux of morphine from the brain is observed.

  • 9.
    Bengtsson, Jörgen
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences, Division of Pharmacokinetics and Drug Therapy.
    Jansson, Britt
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences, Division of Pharmacokinetics and Drug Therapy.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences, Division of Pharmacokinetics and Drug Therapy.
    On-line desalting and determination of morphine, morphine-3-glucuronide and morphine-6-glucuronide in microdialysis and plasma samples using column switching and liquid chromatography/tandem mass spectrometry2005In: Rapid Communications in Mass Spectrometry, ISSN 0951-4198, E-ISSN 1097-0231, Vol. 19, no 15, p. 2116-2122Article in journal (Refereed)
    Abstract [en]

    A sensitive and reproducible method for the determination of morphine and the metabolites morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G) was developed. The method was validated for perfusion fluid used in microdialysis as well as for sheep and human plasma. A C18 guard column was used to desalt the samples before analytical separation on a ZIC HILIC (hydrophilic interaction chromatography) column and detection with tandem mass spectrometry (MS/MS). The mobile phases were 0.05% trifluoroacetic acid (TFA) for desalting and acetonitrile/5 mM ammonium acetate (70:30) for separation. Microdialysis samples (5 microL) were directly injected onto the system. The lower limits of quantification (LLOQ) for morphine, M3G and M6G were 0.50, 0.22 and 0.55 ng/mL, respectively, and the method was linear from LLOQ to 200 ng/mL. For plasma, a volume of 100 microL was precipitated with acetonitrile containing internal standards (deuterated morphine and metabolites). The supernatant was evaporated and reconstituted in 0.05% TFA before the desalting process. The LLOQs for sheep plasma were 2.0 and 3.1 ng/mL and the ranges were 2.0-2000 and 3.1-3100 ng/mL for morphine and M3G, respectively. For human plasma, the LLOQs were 0.78, 1.49 and 0.53 ng/mL and the ranges were 0.78-500, 1.49-1000 and 0.53-500 ng/mL for morphine, M3G and M6G, respectively.

  • 10.
    Boström, Emma
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences, Division of Pharmacokinetics and Drug Therapy.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences, Division of Pharmacokinetics and Drug Therapy.
    Simonsson, Ulrika S. H.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences, Division of Pharmacokinetics and Drug Therapy.
    Blood–Brain Barrier Transport Helps to Explain Discrepancies in In Vivo Potency between Oxycodone and Morphine2008In: Anesthesiology, ISSN 0003-3022, E-ISSN 1528-1175, Vol. 108, no 3, p. 495-505Article in journal (Refereed)
    Abstract [en]

    Background The objective of this study was to evaluate the brain pharmacokinetic-pharmacodynamic relations of un-bound oxycodone and morphine to investigate the influence of blood-brain barrier transport on differences in potency between these drugs. Methods: Microdialysis was used to obtain unbound concentrations in brain and blood. The antinociceptive effect of each drug was assessed using the hot water tail-flick method. Population pharmacokinetic modeling was used to describe the bloodbrain barrier transport of morphine as the rate (Cl.) and extent (K-p,K-uu) of equilibration, where CLin is the influx clearance across the blood-brain barrier and Kp,,,, is the ratio of the unbound concentration in brain to that in blood at steady state. Results: The six-fold difference in K-p,K-uu between oxycodone and morphine implies that, for the same unbound concentration in blood, the concentrations of unbound oxycodone in brain will be six times higher than those of morphine. A joint pharmacokinetic-pharmacodynamic model of oxycodone and morphine based on unbound brain concentrations was developed and used as a statistical tool to evaluate differences in the pharmacodynamic parameters of the drugs. A power model using Effect = Baseline + Slope center dot C-gamma best described the data. Drug-specific slope and gamma parameters made the relative potency of the drugs concentration dependent. Conclusions: For centrally acting drugs such as opioids, pharmacokinetic-pharmacodynamic relations describing the interaction with the receptor are better obtained by correlating the effects to concentrations of unbound drug in the tissue of interest rather than to blood concentrations.

  • 11.
    Boström, Emma
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences, Division of Pharmacokinetics and Drug Therapy.
    Jansson, Britt
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences, Division of Pharmacokinetics and Drug Therapy.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences, Division of Pharmacokinetics and Drug Therapy.
    Simonsson, Ulrika S. H.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences, Division of Pharmacokinetics and Drug Therapy.
    The Use of Liquid Chromatography/Mass Spectrometry for Quantitative Analysis of Oxycodone, Oxymorphone and Noroxycodone in Ringer Solution, Rat Plasma and Rat Brain Tissue2004In: Rapid Communications in Mass Spectrometry, ISSN 0951-4198, E-ISSN 1097-0231, Vol. 18, no 21, p. 2565-2576Article in journal (Refereed)
    Abstract [en]

    Sensitive and reproducible methods for the determination of oxycodone, oxymorphone and noroxycodone in Ringer solution, rat plasma and rat brain tissue by liquid chromatography/mass spectrometry are described. Deuterated analogs of the substances were used as internal standards. Samples in Ringer solution were analyzed by direct injection of 10 microL Ringer solution diluted by an equal volume of water. The limit of quantification was 0.5 ng/mL and the method was linear in the range of 0.5-150 ng/mL for all substances. To analyze oxycodone and oxymorphone in rat plasma, 50 microL of plasma were precipitated with acetonitrile, and the supernatant was directly injected onto the column. To analyze oxycodone, oxymorphone and noroxycodone in rat plasma, 100 microL of rat plasma were subjected to a C18 solid-phase extraction (SPE) procedure, before reconstituting in mobile phase and injection onto the column. For both methods the limit of quantification in rat plasma was 0.5 ng/mL and the methods were linear in the range of 0.5-250 ng/mL for all substances. To analyze the content of oxycodone, oxymorphone and noroxycodone in rat brain tissue, 100 microL of the brain homogenate supernatant were subjected to a C18 SPE procedure. The limit of quantification of oxycodone was 20 ng/g brain, and for oxymorphone and noroxycodone 4 ng/g brain, and the method was linear in the range of 20-1000 ng/g brain for oxycodone and 4-1000 ng/g brain for oxymorphone and noroxycodone. All methods utilized a mobile phase of 5 mM ammonium acetate in 45% acetonitrile, and a SB-CN column was used for separation. The total run time of all methods was 9 min. The intra-day precision and accuracy were <11.3% and <+/-14.9%, respectively, and the inter-day precision and accuracy were <14.9% and <+/-6.5%, respectively, for all the concentrations and matrices described.

  • 12.
    Boström, Emma
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences, Division of Pharmacokinetics and Drug Therapy.
    Simonsson, Ulrika S. H.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences, Division of Pharmacokinetics and Drug Therapy.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences, Division of Pharmacokinetics and Drug Therapy.
    In Vivo Blood-Brain Barrier Transport of Oxycodone in the Rat: Indications for Active Influx and Implications for Pharmacokinetics/Pharmacodynamics2006In: Drug Metabolism And Disposition, ISSN 0090-9556, E-ISSN 1521-009X, Vol. 34, no 9, p. 1624-1631Article in journal (Refereed)
    Abstract [en]

    The blood-brain barrier (BBB) transport of oxycodone was studied in rats. Microdialysis probes were inserted into the striatum and vena jugularis. Ten animals were given a bolus dose followed by a 120-min constant rate infusion to study the steady-state concepts of oxycodone BBB equilibration. Another 10 animals were given a 60-min constant rate infusion to study the rate of equilibration across the BBB. Oxycodone-D3 was used as a calibrator for the microdialysis experiments. The samples were analyzed with a liquid chromatography-tandem mass spectrometry method and a population pharmacokinetic model was used to simultaneously fit all the data using NONMEM. A two-compartment model which allowed for a delay between the venous and arterial compartments best described the pharmacokinetics for oxycodone in blood and plasma, whereas a one-compartment model was sufficient to describe the pharmacokinetics in the brain. The BBB transport of oxycodone was parameterized as CL(in) and K(p,uu). CL(in) describes the clearance of oxycodone across the BBB into the brain, whereas K(p,uu) describes the extent of drug equilibration across the BBB. CL(in) across the BBB was estimated to 1910 microl/min x g brain. K(p,uu) was estimated to 3.0, meaning that the unbound concentration of oxycodone in brain was 3 times higher than in blood, which is an indication of active influx of oxycodone at the BBB. This is the first evidence of an opioid having an unbound steady-state concentration in brain that is higher than unity, which can explain potency discrepancies between oxycodone and other opioids.

  • 13.
    Boström, Emma
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences, Division of Pharmacokinetics and Drug Therapy.
    Simonsson, Ulrika S. H.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences, Division of Pharmacokinetics and Drug Therapy.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences, Division of Pharmacokinetics and Drug Therapy.
    Oxycodone Pharmacokinetics and Pharmacodynamics in the Rat in the Presence of the P-Glycoprotein Inhibitor PSC8332005In: Journal of Pharmaceutical Sciences, ISSN 0022-3549, E-ISSN 1520-6017, Vol. 94, no 5, p. 1060-1066Article in journal (Refereed)
    Abstract [en]

    The objective of this study was to investigate the in vivo influence of the P-glycoprotein (P-gp) inhibitor PSC833 on the plasma pharmacokinetics, total brain concentrations and tail-flick latency of oxycodone in rats. Eight rats each received an infusion of PSC833 or vehicle without PSC833. One hour later, all animals received 0.3 mg/kg oxycodone as a 1-h infusion. Plasma samples were taken, and tail-flick latency was monitored during the infusion and for 2 h thereafter. The brains were collected at the end of the experiment. There were no differences between the two groups in area under the plasma oxycodone concentration-time curve from time zero to infinity, or oxycodone plasma clearance, volume of distribution at steady-state, or half-life. There were no differences in average total brain oxycodone concentrations at 180 min, nor were there any differences in average tail-flick latency for the PSC833 and control groups. In conclusion, coadministration of PSC833 did not alter the plasma pharmacokinetics, brain concentrations, or associated tail-flick latency of oxycodone, indicating that oxycodone is not a P-gp substrate in the rat. This has important clinical implications, as it indicates that oxycodone, unlike some other opioids, will not interact at the blood-brain barrier (BBB) with concomitantly administered P-gp substrates.

  • 14.
    Bouw, M. René
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences, Division of Pharmacokinetics and Drug Therapy.
    Xie, Rujia
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences, Division of Pharmacokinetics and Drug Therapy.
    Tunblad, Karin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences, Division of Pharmacokinetics and Drug Therapy.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences, Division of Pharmacokinetics and Drug Therapy.
    Blood-brain barrier transport and brain distribution of morphine-6-glucuronide in relation to the antinociceptive effect in rats: pharmacokinetic/pharmacodynamic modelling2001In: British Journal of Pharmacology, ISSN 0007-1188, E-ISSN 1476-5381, Vol. 134, no 8, p. 1796-1804Article in journal (Refereed)
    Abstract [en]

    1. The objective of this study was to investigate the contribution of the blood-brain barrier (BBB) transport to the delay in antinociceptive effect of morphine-6-glucuronide (M6G), and to study the equilibration of M6G in vivo across the BBB with microdialysis measuring unbound concentrations. 2. On two consecutive days, rats received an exponential infusion of M6G for 4 h aiming at a target concentration of 3000 ng ml(-1) (6.5 microM) in blood. Concentrations of unbound M6G were determined in brain extracellular fluid (ECF) and venous blood using microdialysis and in arterial blood by regular sampling. MD probes were calibrated in vivo using retrodialysis by drug prior to drug administration. 3. The half-life of M6G was 23+/-5 min in arterial blood, 26+/-10 min in venous blood and 58+/-17 min in brain ECF (P<0.05; brain vs blood). The BBB equilibration, expressed as the unbound steady-state concentration ratio, was 0.22+/-0.09, indicating active efflux in the BBB transport of M6G. A two-compartment model best described the brain distribution of M6G. The unbound volume of distribution was 0.20+/-0.02 ml g brain(-1). The concentration-antinociceptive effect relationships exhibited a clear hysteresis, resulting in an effect delay half-life of 103 min in relation to blood concentrations and a remaining effect delay half-life of 53 min in relation to brain ECF concentrations. 4. Half the effect delay of M6G can be explained by transport across the BBB, suggesting that the remaining effect delay of 53 min is a result of drug distribution within the brain tissue or rate-limiting mechanisms at the receptor level.

  • 15.
    Bäckström, Erica
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences. AstraZeneca R&D Gothenburg, Resp Inflammat & Autoimmun Innovat Med, S-43183 Molndal, Sweden..
    Boger, Elin
    AstraZeneca R&D Gothenburg, Resp Inflammat & Autoimmun Innovat Med, S-43183 Molndal, Sweden.;Univ Warwick, Sch Engn, Coventry CV4 7AL, W Midlands, England..
    Lundqvist, Anders
    AstraZeneca R&D Gothenburg, Resp Inflammat & Autoimmun Innovat Med, S-43183 Molndal, Sweden..
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Fridén, Markus
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences. AstraZeneca R&D Gothenburg, Resp Inflammat & Autoimmun Innovat Med, S-43183 Molndal, Sweden..
    Lung Retention by Lysosomal Trapping of Inhaled Drugs Can Be Predicted In Vitro With Lung Slices2016In: Journal of Pharmaceutical Sciences, ISSN 0022-3549, E-ISSN 1520-6017, Vol. 105, no 11, p. 3432-3439Article in journal (Refereed)
    Abstract [en]

    Modulating and optimizing the local pharmacokinetics of inhaled drugs by chemical design or formulation is challenged by the lack of predictive in vitro systems and in vivo techniques providing a detailed description of drug location in the lung. The present study investigated whether a new experimental setup of freshly prepared agarose-filled lung slices can be used to estimate lung retention in vitro, by comparing with in vivo lung retention after intratracheal instillation. Slices preloaded with inhaled beta-adrenergic compounds (salbutamol, formoterol, salmeterol, indacaterol or AZD3199) were incubated in a large volume of buffer (w/wo monensin to assess the role of lysosomal trapping), and the amount remaining in slices at different time points was determined with liquid chromatography-tandem mass spectrometry. The in vitro lung retention closely matched the in vivo lung retention (half-lives within 3-fold for 4/5 compounds), and monensin shortened the half-lives for all compounds. The results suggest that freshly prepared rat lungs slices can be used to predict lung retention and that slow kinetics of lysosomal trapping is a key mechanism by which retention in the lung and the effect duration of inhaled beta-adrenergic bronchodilators are prolonged.

  • 16.
    Bäckström, Erica
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences. AstraZeneca R&D, Resp Inflammat & Autoimmun Innovat Med, S-43183 Molndal, Sweden.
    Lundqvist, Anders
    AstraZeneca R&D, Resp Inflammat & Autoimmun Innovat Med, S-43183 Molndal, Sweden.
    Boger, Elin
    AstraZeneca R&D, Resp Inflammat & Autoimmun Innovat Med, S-43183 Molndal, Sweden.; Univ Warwick, Sch Engn, Coventry CV4 7AL, W Midlands, England.
    Svanberg, Petter
    AstraZeneca R&D, Resp Inflammat & Autoimmun Innovat Med, S-43183 Molndal, Sweden.
    Ewing, Pär
    AstraZeneca R&D, Resp Inflammat & Autoimmun Innovat Med, S-43183 Molndal, Sweden.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Fridén, Markus
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences. AstraZeneca R&D, Resp Inflammat & Autoimmun Innovat Med, S-43183 Molndal, Sweden.
    Development of a Novel Lung Slice Methodology for Profiling of Inhaled Compounds2016In: Journal of Pharmaceutical Sciences, ISSN 0022-3549, E-ISSN 1520-6017, Vol. 105, no 2, p. 838-845Article in journal (Refereed)
    Abstract [en]

    The challenge of defining the concentration of unbound drug at the lung target site after inhalation limits the possibility to optimize target exposure by compound design. In this study, a novel rat lung slice methodology has been developed and applied to study drug uptake in lung tissue, and the mechanisms by which this occurs. Freshly prepared lung slices (500 μm) from drug-naive rats were incubated with drugs followed by determination of the unbound drug volume of distribution in lung (Vu,lung), as the total concentration of drug in slices divided by the buffer (unbound) concentration. Vu,lung determined for a set of inhaled drug compounds ranged from 2.21 mL/g for salbutamol to 2970 mL/g for dibasic compound A. Co-incubation with monensin, a modulator of lysosomal pH, resulted in inhibition of tissue uptake of basic propranolol to 13%, indicating extensive lysosomal trapping. Partitioning into cells was particularly high for the cation MPP+ and the dibasic compound A, likely because of the carrier-mediated transport and lysosomal trapping. The results show that different factors are important for tissue uptake and the presented method can be used for profiling of inhaled compounds, leading to a greater understanding of distribution and exposure of drug in the lung.

  • 17.
    Chen, Xiaomei
    et al.
    Univ Michigan, Coll Pharm, Dept Pharmaceut Sci, 428 Church St, Ann Arbor, MI 48109 USA..
    Keep, Richard F.
    Univ Michigan Hlth Syst, Dept Neurosurg, Ann Arbor, MI USA..
    Liang, Yan
    Univ Michigan, Coll Pharm, Dept Clin Pharm, 428 Church St, Ann Arbor, MI 48109 USA..
    Zhu, Hao-Jie
    Univ Michigan, Coll Pharm, Dept Clin Pharm, 428 Church St, Ann Arbor, MI 48109 USA..
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Hu, Yongjun
    Univ Michigan, Coll Pharm, Dept Pharmaceut Sci, 428 Church St, Ann Arbor, MI 48109 USA..
    Smith, David E.
    Univ Michigan, Coll Pharm, Dept Pharmaceut Sci, 428 Church St, Ann Arbor, MI 48109 USA..
    Influence of peptide transporter 2 (PEPT2) on the distribution of cefadroxil in mouse brain: A microdialysis study2017In: Biochemical Pharmacology, ISSN 0006-2952, E-ISSN 1356-1839, Vol. 131, p. 89-97Article in journal (Refereed)
    Abstract [en]

    Peptide transporter 2 (PEPT2) is a high-affinity low-capacity transporter belonging to the proton-coupled oligopeptide transporter family. Although many aspects of PEPT2 structure-function are known, including its localization in choroid plexus and neurons, its regional activity in brain, especially extracellular fluid (ECF), is uncertain. In this study, the pharmacokinetics and regional brain distribution of cefadroxil, a beta-lactam antibiotic and PEN 2 substrate, were investigated in wildtype and Pept2 null mice using in vivo intracerebral microdialysis. Cefadroxil was infused intravenously over 4 h at 0.15 mg/min/kg, and samples obtained from plasma, brain ECF, cerebrospinal fluid (CSF) and brain tissue. A permeability surface area experiment was also performed in which 0.15 mg/min/kg cefadroxil was infused intravenously for 10 min, and samples obtained from plasma and brain tissues. Our results showed that PEPT2 ablation significantly increased the brain ECF and CSF levels of cefadroxil (2- to 2.5-fold). In contrast, there were no significant differences between wildtype and Pept2 null mice in the amount of cefadroxil in brain cells. The unbound volume of distribution of cefadroxil in brain was 60% lower in Pept2 null mice indicating an uptake function for PEPT2 in brain cells. Finally, PEPT2 did not affect the influx clearance of cefadroxil, thereby, ruling out differences between the two genotypes in drug entry across the blood-brain barriers. These findings demonstrate, for the first time, the impact of PEPT2 on brain ECF as well as the known role of PEPT2 in removing peptide-like drugs, such as cefadroxil, from the CSF to blood.

  • 18.
    Chen, Xiaomei
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Loryan, Irena
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Maryam, Payan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Keep, Richard F
    University of Michigan, Ann Arbor, MI, USA.
    Smith, David E
    University of Michigan, Ann Arbor, MI, USA.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Effect of transporter inhibitioin on the distribution of cefadroxil in rat brain2014In: Fluids and Barriers of the CNS, ISSN 2045-8118, E-ISSN 2045-8118, Vol. 11, no 25, p. 1-12Article in journal (Refereed)
  • 19.
    Chen, Xiaomei
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Loryan, Irena
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Payan, Maryam
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Keep, Richard
    Smith, David E
    Margareta, Hammarlund-Udenaes
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Effect of transporter inhibition on the distribution of cefadroxil in rat brain2014In: Fluids and Barriers of the CNS, ISSN 2045-8118, E-ISSN 2045-8118, Vol. 11, article id 25Article in journal (Refereed)
    Abstract [en]

    Background

    Cefadroxil, a cephalosporin antibiotic, is a substrate for several membrane transporters including peptide transporter 2 (PEPT2), organic anion transporters (OATs), multidrug resistance-associated proteins (MRPs), and organic anion transporting polypeptides (OATPs). These transporters are expressed at the blood-brain barrier (BBB), blood-cerebrospinal fluid barrier (BCSFB), and/or brain cells. The effect of these transporters on cefadroxil distribution in brain is unknown, especially in the extracellular and intracellular fluids within brain.

    Methods

    Intracerebral microdialysis was used to measure unbound concentrations of cefadroxil in rat blood, striatum extracellular fluid (ECF) and lateral ventricle cerebrospinal fluid (CSF). The distribution of cefadroxil in brain was compared in the absence and presence of probenecid, an inhibitor of OATs, MRPs and OATPs, where both drugs were administered intravenously. The effect of PEPT2 inhibition by intracerebroventricular (icv) infusion of Ala-Ala, a substrate of PEPT2, on cefadroxil levels in brain was also evaluated. In addition, using an in vitro brain slice method, the distribution of cefadroxil in brain intracellular fluid (ICF) was studied in the absence and presence of transport inhibitors (probenecid for OATs, MRPs and OATPs; Ala-Ala and glycylsarcosine for PEPT2).

    Results

    The ratio of unbound cefadroxil AUC in brain ECF to blood (Kp,uu,ECF) was ~2.5-fold greater during probenecid treatment. In contrast, the ratio of cefadroxil AUC in CSF to blood (Kp,uu,CSF) did not change significantly during probenecid infusion. Icv infusion of Ala-Ala did not change cefadroxil levels in brain ECF, CSF or blood. In the brain slice study, Ala-Ala and glycylsarcosine decreased the unbound volume of distribution of cefadroxil in brain (Vu,brain), indicating a reduction in cefadroxil accumulation in brain cells. In contrast, probenecid increased cefadroxil accumulation in brain cells, as indicated by a greater value for Vu,brain.

    Conclusions

    Transporters (OATs, MRPs, and perhaps OATPs) that can be inhibited by probenecid play an important role in mediating the brain-to-blood efflux of cefadroxil at the BBB. The uptake of cefadroxil in brain cells involves both the influx transporter PEPT2 and efflux transporters (probenecid-inhibitable). These findings demonstrate that drug-drug interactions via relevant transporters may affect the distribution of cephalosporins in both brain ECF and ICF.

  • 20.
    Chen, Xiaomei
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences. Univ Michigan, Coll Pharm, Dept Pharmaceut Sci, 428 Church St, Ann Arbor, MI 48109 USA..
    Slättengren, Tim
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    de Lange, Elizabeth C. M.
    Leiden Acad Ctr Drug Res, Dept Pharmacol, Leiden, Netherlands..
    Smith, David E.
    Univ Michigan, Coll Pharm, Dept Pharmaceut Sci, 428 Church St, Ann Arbor, MI 48109 USA..
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Revisiting atenolol as a low passive permeability marker2017In: Fluids and Barriers of the CNS, ISSN 2045-8118, E-ISSN 2045-8118, Vol. 14, article id 30Article in journal (Refereed)
    Abstract [en]

    Background: Atenolol, a hydrophilic beta blocker, has been used as a model drug for studying passive permeability of biological membranes such as the blood-brain barrier (BBB) and the intestinal epithelium. However, the extent of S-atenolol (the active enantiomer) distribution in brain has never been evaluated, at equilibrium, to confirm that no transporters are involved in its transport at the BBB.

    Methods: To assess whether S-atenolol, in fact, depicts the characteristics of a low passive permeable drug at the BBB, a microdialysis study was performed in rats to monitor the unbound concentrations of S-atenolol in brain extracellular fluid (ECF) and plasma during and after intravenous infusion. A pharmacokinetic model was developed, based on the microdialysis data, to estimate the permeability clearance of S-atenolol into and out of brain. In addition, the nonspecific binding of S-atenolol in brain homogenate was evaluated using equilibrium dialysis.

    Results: The steady-state ratio of unbound S-atenolol concentrations in brain ECF to that in plasma (i.e., -K-p,K-uu,K-brain) was 3.5% +/- 0.4%, a value much less than unity. The unbound volume of distribution in brain -(V-u,V- brain) of S-atenolol was also calculated as 0.69 +/- 0.10 mL/g brain, indicating that S-atenolol is evenly distributed within brain parenchyma. Lastly, equilibrium dialysis showed limited nonspecific binding of S-atenolol in brain homogenate with an unbound fraction -(f(u, brain)) of 0.88 +/- 0.07.

    Conclusions: It is concluded, based on -K-p,K-uu,K-brain being much smaller than unity, that S-atenolol is actively effluxed at the BBB, indicating the need to re-consider S-atenolol as a model drug for passive permeability studies of BBB transport or intestinal absorption.

  • 21.
    de Lange, E. C. M.
    et al.
    Leiden University, the Netherlands.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences. Uppsala University.
    Translational Aspects of Blood-Brain Barrier Transport and Central Nervous System Effects of Drugs: From Discovery to Patients2015In: Clinical Pharmacology and Therapeutics, ISSN 0009-9236, E-ISSN 1532-6535, Vol. 97, no 4, p. 380-394Article in journal (Refereed)
    Abstract [en]

    The development of CNS drugs is associated with high failure rates. It is postulated that too much focus has been put on BBB permeability and too little on understanding BBB transport, which is the main limiting factor in drug delivery to the brain. An integrated approach to collecting, understanding, and handling pharmacokinetic-pharmacodynamic information from early discovery stages to the clinic is therefore recommended in order to improve translation to human drug treatment.

  • 22.
    Eriksson, Olle
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health.
    Bäckström, Torbjörn
    Stridsberg, Mats
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Naessén, Tord
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health.
    Differential response to estrogen challenge test in women with and without premenstrual dysphoria2006In: Psychoneuroendocrinology, ISSN 0306-4530, E-ISSN 1873-3360, Vol. 31, no 4, p. 415-427Article in journal (Refereed)
    Abstract [en]

    This study tested the hypothesis that brain sensitivity to normal fluctuations in gonadal hormones is increased in women with premenstrual dysphoria. For this purpose, the effect of a common gonadal hormonal challenge on the sensitivity of the brain was investigated in 13 women with premenstrual dysphoria and 12 asymptomatic controls. The estrogen challenge test, comprising estradiolbenzoate 0.04 mg/kg, was given as an intramuscular gluteal injection between 0700 and 1000h on day 3 or 4 of the menstrual cycle; blood was sampled at 0, 0.6, 6.5, 24, 32, 48, 56, 72, 96, 120, and 144h and analyzed for estradiol, FSH and LH. Serum estradiol levels after the injection and the corresponding FSH responses were similar between the study groups; however, the LH responses were significantly different. Women with premenstrual dysphoria had a relatively stronger negative feedback response (p=0.014) up to the point of nadir LH levels (maximal negative feedback), but displayed higher LH levels at the nadir (p=0.01), more LH surge-like reactions (p=0.047), and a 50% higher area under the curve (AUC) for LH (p=0.03) than controls. The LH response in women with premenstrual dysphoria was related to the VAS-rated symptoms; the negative increment (AOC) correlated to luteal phase "bloating" (r(s)=0.73; p=0.0069) whereas the AUC of LH correlated to "irritability" (r(s)=0.58; p=0.040). A significant interaction term between study group and changes in LH during the negative feedback phase (32-0h), with regard to luteal phase "irritability" was found (test for interaction p=0.005). For the premenstrual dysphoria group, ratings of "depressed mood"were related to baseline FSH levels (r(s)=0.60; p=0.034), and to the AUC of FSH during the negative feedback phase (r(s)=0.58; p=0.043). Women with premenstrual dysphoria displayed a gonadotrophin response to estradiol challenge that differed from that of controls, and was correlated to symptom severity.

  • 23.
    Fridén, Markus
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Bergström, Fredrik
    Wan, Hong
    Rehngren, Mikael
    Ahlin, Gustav
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Bredberg, Ulf
    Measurement of Unbound Drug Exposure in Brain: Modelling of pH Partitioning Explains Diverging Results between the Brain Slice and Brain Homogenate Methods2011In: Drug Metabolism And Disposition, ISSN 0090-9556, E-ISSN 1521-009X, Vol. 39, no 3, p. 353-362Article in journal (Refereed)
    Abstract [en]

    Currently used methodology for determining unbound drug exposure in brain combines measurement of the total drug concentration in the whole brain in vivo with estimation of brain tissue binding from one of two available in vitro methods: equilibrium dialysis of brain homogenate and the brain slice uptake method. This study of 56 compounds compares the fraction of unbound drug in brain (f(u,brain)), determined using the brain homogenate method, with the unbound volume of distribution in brain (V(u,brain)), determined using the brain slice method. Discrepancies were frequent and primarily related to drug pH partitioning, due to the preservation of cellular structures in the slice that are absent in the homogenate. A mathematical model for pH partitioning into acidic intracellular compartments was derived to predict the slice V(u,brain) from measurements of f(u,brain) and drug pKa. This model allowed prediction of V(u,brain) from f(u,brain) within a 2.2-fold error range for 95% of the drugs, as compared to a 4.5-fold error range using the brain homogenate f(u,brain) method alone. The greatest discrepancies between the methods occurred with compounds that are actively transported into brain cells, including gabapentin, metformin and prototypic organic cation transporter substrates. It is concluded that intra-brain drug distribution is governed by several diverse mechanisms in addition to non-specific binding and that the slice method is therefore more reliable than the homogenate method. Alternatively, predictions of V(u,brain) can be made from homogenate f(u,brain) using the presented pH partition model, although this model does not take into consideration possible active brain cell uptake.

  • 24.
    Fridén, Markus
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Ducrozet, Frederic
    Middleton, Brian
    Antonsson, Madeleine
    Bredberg, Ulf
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Development of a High-Throughput Brain Slice Method for Studying Drug Distribution in the Central Nervous System2009In: Drug Metabolism And Disposition, ISSN 0090-9556, E-ISSN 1521-009X, Vol. 37, no 6, p. 1226-1233Article in journal (Refereed)
    Abstract [en]

    New, more efficient methods of estimating unbound drug concentrations in the CNS combine the amount of drug in whole brain tissue samples measured by conventional methods with in vitro estimates of the unbound brain volume of distribution (Vu,brain). While the brain slice method is the most reliable in vitro method for measuring Vu,brain, it has not previously been adapted for the needs of drug discovery research. The aim of this study was to increase the throughput and optimize the experimental conditions of this method. Equilibrium of drug between the buffer and the brain slice within the 4-5 hours of incubation is a fundamental requirement. However, it is difficult to meet this requirement for many of the extensively binding, lipophilic compounds in drug discovery programmes. In this study, the dimensions of the incubation vessel and mode of stirring influenced the equilibration time, as did the amount of brain tissue per unit buffer volume. The use of casette experiments for investigating Vu,brain in a linear drug concentration range increased the throughput of the method. The Vu,brain for the model compounds ranged from mL*g brain(-1); the sources of variability are discussed. The optimized set-up of the brain slice method allows precise, robust estimation of Vu,brain for drugs with diverse properties, including highly lipophilic compounds. This is a critical step forward for the implementation of relevant measurements of CNS exposure in the drug discovery setting.

  • 25.
    Fridén, Markus
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Gupta, Anubha
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Antonsson, Madeleine
    Bredberg, Ulf
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    In vitro methods for estimating unbound drug concentrations in the brain interstitial and intracellular fluids2007In: Drug Metabolism And Disposition, ISSN 0090-9556, E-ISSN 1521-009X, Vol. 35, no 9, p. 1711-1719Article in journal (Refereed)
    Abstract [en]

    Concentrations of unbound drug in the interstitial fluid of the brain are not rapidly measured in vivo. Therefore, measurement of total drug levels, i.e., the amount of drug per gram of brain, has been a common but unhelpful practice in drug discovery programs relating to central drug effects. This study was designed to evaluate in vitro techniques for faster estimation of unbound drug concentrations. The parameter that relates the total drug level and the unbound interstitial fluid concentration is the unbound volume of distribution in the brain (V(u,brain)). It was measured in vitro for 15 drugs using brain slice uptake and brain homogenate binding methods. The results were validated in vivo by comparison with V(u,brain) microdialysis results. The slice method results were within a 3-fold range of the in vivo results for all but one compound, suggesting that this method could be used in combination with total drug levels to estimate unbound interstitial fluid concentrations within reasonable limits. Although successful in 10 of 15 cases, the brain homogenate binding method failed to estimate the V(u,brain) of drugs that reside predominantly in the interstitial space or compounds that are accumulated intracellularly. Use of the simple methods described in this article will 1) allow quantification of active transport at the blood-brain barrier in vivo, 2) facilitate the establishment of a relationship between in vitro potency and in vivo activity for compounds acting on central nervous system targets, and 3) provide information on intracellular concentrations of unbound drug.

  • 26.
    Fridén, Markus
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Ljungqvist, Helena
    Middleton, Brian
    Bredberg, Ulf
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Improved measurement of drug exposure in the brain using drug-specific correction for residual blood2010In: Journal of Cerebral Blood Flow and Metabolism, ISSN 0271-678X, E-ISSN 1559-7016, Vol. 30, no 1, p. 150-161Article in journal (Refereed)
    Abstract [en]

    A major challenge associated with the determination of the unbound brain-to-plasma concentration ratio of a drug (K(p,uu,brain)), is the error associated with correction for the drug in various vascular spaces of the brain, i.e., in residual blood. The apparent brain vascular spaces of plasma water (V(water), 10.3 microL/g brain), plasma proteins (V(protein), 7.99 microL/g brain), and the volume of erythrocytes (V(er), 2.13 microL/g brain) were determined and incorporated into a novel, drug-specific correction model that took the drug-unbound fraction in the plasma (f(u,p)) into account. The correction model was successfully applied for the determination of K(p,uu,brain) for indomethacin, loperamide, and moxalactam, which had potential problems associated with correction. The influence on correction of the drug associated with erythrocytes was shown to be minimal. Therefore, it is proposed that correction for residual blood can be performed using an effective plasma space in the brain (V(eff)), which is calculated from the measured f(u,p) of the particular drug as well as from the estimates of V(water) and V(protein), which are provided in this study. Furthermore, the results highlight the value of determining K(p,uu,brain) with statistical precision to enable appropriate interpretation of brain exposure for drugs that appear to be restricted to the brain vascular spaces.

  • 27.
    Fridén, Markus
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Winiwarter, Susanne
    Jerndal, Gunilla
    Bengtsson, Ola
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Wan, Hong
    Bredberg, Ulf
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Antonsson, Madeleine
    Structure-brain exposure relationships in rat and human using a novel data set of unbound drug concentrations in brain interstitial and cerebrospinal fluids2009In: Journal of Medicinal Chemistry, ISSN 0022-2623, E-ISSN 1520-4804, Vol. 52, no 20, p. 6233-6243Article in journal (Refereed)
    Abstract [en]

    New experimental methodologies were applied to measure the unbound brain-to-plasma concentration ratio (K(p,uu,brain)) and the unbound CSF-to-plasma concentration ratio (K(p,uu,CSF)) in rats for 43 structurally diverse drugs. The relationship between chemical structure and K(p,uu,brain) was dominated by hydrogen bonding. Contrary to popular understanding based on the total brain-to-plasma concentration ratio (logBB), lipophilicity was not a determinant of unbound brain exposure. Although changing the number of hydrogen bond acceptors is a useful design strategy for optimizing K(p,uu,brain), future improvement of in silico prediction models is dependent on the accommodation of active drug transport. The structure-brain exposure relationships found in the rat also hold for humans, since the rank order of the drugs was similar for human and rat K(p,uu,CSF). This cross-species comparison was supported by K(p,uu,CSF) being within 3-fold of K(p,uu,brain) in the rat for 33 of 39 drugs. It was, however, also observed that K(p,uu,CSF) overpredicts K(p,uu,brain) for highly effluxed drugs, indicating lower efflux capacity of the blood-cerebrospinal fluid barrier compared to the blood-brain barrier.

  • 28.
    Gillespie, Ulrika
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Alassaad, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical pharmacogenomics and osteoporosis.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Morlin, Claes
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Henrohn, Dan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Bertilsson, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, UCR-Uppsala Clinical Research Center.
    Melhus, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical pharmacogenomics and osteoporosis.
    Effects of Pharmacists' Interventions on Appropriateness of Prescribing and Evaluation of the Instruments' (MAI, STOPP and STARTs') Ability to Predict Hospitalization-Analyses from a Randomized Controlled Trial2013In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 8, no 5, p. e62401-Article in journal (Refereed)
    Abstract [en]

    Background: Appropriateness of prescribing can be assessed by various measures and screening instruments. The aims of this study were to investigate the effects of pharmacists' interventions on appropriateness of prescribing in elderly patients, and to explore the relationship between these results and hospital care utilization during a 12-month follow-up period. Methods: The study population from a previous randomized controlled study, in which the effects of a comprehensive pharmacist intervention on re-hospitalization was investigated, was used. The criteria from the instruments MAI, STOPP and START were applied retrospectively to the 368 study patients (intervention group (I) n = 182, control group (C) n = 186). The assessments were done on admission and at discharge to detect differences over time and between the groups. Hospital care consumption was recorded and the association between scores for appropriateness, and hospitalization was analysed. Results: The number of Potentially Inappropriate Medicines (PIMs) per patient as identified by STOPP was reduced for I but not for C (1.42 to 0.93 vs. 1.46 to 1.66 respectively, p<0.01). The number of Potential Prescription Omissions (PPOs) per patient as identified by START was reduced for I but not for C (0.36 to 0.09 vs. 0.42 to 0.45 respectively, p<0.001). The summated score for MAI was reduced for I but not for C (8.5 to 5.0 and 8.7 to 10.0 respectively, p<0.001). There was a positive association between scores for MAI and STOPP and drug-related readmissions (RR 8-9% and 30-34% respectively). No association was detected between the scores of the tools and total re-visits to hospital. Conclusion: The interventions significantly improved the appropriateness of prescribing for patients in the intervention group as evaluated by the instruments MAI, STOPP and START. High scores in MAI and STOPP were associated with a higher number of drug-related readmissions.

  • 29.
    Gillespie, Ulrika
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Alassaad, Anna
    Hospital Pharmacy, University Hospital of Uppsala, Sweden.
    Henrohn, Dan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Rheumatology.
    Garmo, Hans
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Toss, Henrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Internal Medicine.
    Kettis-Lindblad, Åsa
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Melhus, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Pharmacology.
    Mörlin, Claes
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Internal Medicine.
    A comprehensive pharmacist intervention to reduce morbidity in patients 80 years or older: a randomized controlled trial2009In: Archives of Internal Medicine, ISSN 0003-9926, E-ISSN 1538-3679, Vol. 169, no 9, p. 894-900Article in journal (Refereed)
    Abstract [en]

    BACKGROUND

    Patients 80 years or older are underrepresented in scientific studies. The objective of this study was to investigate the effectiveness of interventions performed by ward-based pharmacists in reducing morbidity and use of hospital care among older patients.

    METHODS

    A randomized controlled study of patients 80 years or older was conducted at the University Hospital of Uppsala, Uppsala, Sweden. Four hundred patients were recruited consecutively between October 1, 2005, and June 30, 2006, and were randomized to control (n = 201) and intervention (n = 199) groups. The interventions were performed by ward-based pharmacists. The control group received standard care without direct involvement of pharmacists at the ward level. The primary outcome measure was the frequency of hospital visits (emergency department and readmissions [total and drug-related]) during the 12-month follow-up period.

    RESULTS

    Three hundred sixty-eight patients (182 in the intervention group and 186 in the control group) were analyzed. For the intervention group, there was a 16% reduction in all visits to the hospital (quotient, 1.88 vs 2.24; estimate, 0.84; 95% confidence interval [CI], 0.72-0.99) and a 47% reduction in visits to the emergency department (quotient, 0.35 vs 0.66; estimate, 0.53; 95% CI, 0.37-0.75). Drug-related readmissions were reduced by 80% (quotient, 0.06 vs 0.32; estimate, 0.20; 95% CI, 0.10-0.41). After inclusion of the intervention costs, the total cost per patient in the intervention group was $230 lower than that in the control group.

    CONCLUSION

    If implemented on a population basis, the addition of pharmacists to health care teams would lead to major reductions in morbidity and health care costs.

  • 30.
    Gillespie, Ulrika
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Alassaad, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Melhus, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical pharmacogenomics and osteoporosis.
    Mörlin, Claes
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Henrohn, Dan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Bertilsson, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, UCR-Uppsala Clinical Research Center.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Effects of pharmacists’ interventions on appropriateness of prescribing for elderly and exploration of a possible correlation between scores for appropriateness and clinical outcomes: analyses from a randomized controlled trialManuscript (preprint) (Other academic)
    Abstract [en]

    Background:

    Inappropriate prescribing can cause substantial morbidity and represents a clinical and economic burden for patients and society. Appropriateness of prescribing can be assessed by various measures and screening tools, however, for a tool to be valid there should be casual links to important clinical health outcomes. The aim of this study was to investigate the effect of a pharmacist intervention on appropriateness of prescribing, and to explore the relationship between these results and clinical health outcomes defined as re-visits to hospital.

    Methods:

    The study population from a previous randomized controlled study, in which the effects of a comprehensive pharmacist intervention on re-hospitalisation was investigated, was used. The criteria from the validated instruments STOPP, START and MAI were applied retrospectively to the study patients (368 patients; intervention group n=182, control group n=186). The quality assessments were done on admission and at discharge to detect differences over time between the control- and the intervention group. Hospital care consumption one year after admission was recorded and the correlation between scores for appropriateness, as well as number of drugs at discharge, and hospital visits was analysed.

    Results:

    The number of Potentially Inappropriate Medicines (PIMs) per patient as identified by STOPP was reduced for the intervention group but not for the control group (1.42 and 0.93 vs. 1.46 and 1.66 respectively, p<0.01) The number of Potential Prescription Omissions (PPOs) per patient as identified by START was reduced for the intervention group but not for the control group (0.36 and 0.09 vs. 0.42 and 0.45 respectively, p<0.001). The summated score for MAI was reduced for the intervention group but not for the control group (8.5 to 5.0 and 8.7 to 10.0 respectively, p< 0.001). There was no correlation between the scores of the tools and total visits to hospital. Number of drugs (unadjusted) correlated with visits to hospital and the rate ratio was 4%. For readmissions to hospital, MAI (unadjusted) and the number of drugs showed a positive correlation. There was a correlation between MAI and STOPP and drug-related readmissions (RR 8-9% and 30-34% respectively).

    Conclusion:

    The addition of a comprehensive pharmacist service to standard care significantly improved the appropriateness of prescribing for patients in the intervention group that participated in the randomized controlled trial, as evaluated by all three instruments used; STOPP, START and MAI. However, the results on correlation between the tools and re-visits to hospital were inconclusive.

  • 31.
    Gillespie, Ulrika
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Mörlin, Claes
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Hedström, Mariann
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Caring Sciences.
    Perceived value of ward-based pharmacists from the perspective of physicians and nurses2012In: International Journal of Clinical Pharmacy, ISSN 2210-7703, E-ISSN 2210-7711, Vol. 34, no 1, p. 127-135Article in journal (Refereed)
    Abstract [en]

    Background

    Clinical pharmacy in a hospital setting is relatively new in Sweden. Its recent introduction at the University Hospital in Uppsala has provided an opportunity for evaluation by other relevant professionals of the integration of clinical pharmacists into the health-care team.

    Objectives

    The objectives of this descriptive study were to evaluate the perceived value of wardbased clinical pharmacists from the perspective of hospital based physicians and nurses and to identify potential advantages and disadvantages related to the new inter professional collaboration. Another objective was to evaluate the experiences of general practitioners on receiving medication reports from wardbased clinical pharmacists.

    Setting

    Two acute internal medicine wards at the University Hospital in Uppsala, where a previously reported randomized controlled trial investigating the effects of ward based clinical pharmacists on re-visits to hospital was undertaken.

    Methods

    Data were collected by questionnaires containing closed- and openended questions. The questionnaires were distributed during the nine-month study period of the randomized controlled trial by an independent researcher to 29 hospital-based physicians and 44 nurses on the study wards and to 21 general practitioners who had received two or more medication reports. Answers were analysed descriptively for the closedended questions and by content analysis for the open-ended questions.

    Main outcome measure

    The main outcome measure was the physicians’ and nurses’ level of satisfaction with the new collaboration with clinical pharmacists, from a hospital and primary care perspective.

    Results

    Seventy-six percent of the hospital-based physicians and 81% of the nurses completed the questionnaire. Ninety-five percent of the physicians and 93% of the nurses were very satisfied with the collaboration. Out of the 17 general practitioners (81%) that completed the questionnaire 71% wanted to continue to receive medication reports in a similar way in the future. Increased patient safety and improvements in patients’ drug therapy were the main advantages stated by all three groups of respondents. Eighteen percent of the hospital-based physicians and 21% of the nurses thought that the collaboration had been time-consuming to certain or to a high extent.

    Conclusions

    The majority of the respondents, both GPs and hospital based physicians and nurses, were satisfied with the new collaboration with the ward based pharmacists and perceived that the quality of the patients’ drug therapy and drug-related patient safety had increased.

  • 32.
    Greenwood, John
    et al.
    UCL, Inst Ophthalmol, London EC1V 9EL, England..
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Jones, Hazel C.
    Gagle Brook House, Bicester OX26 1UF, Oxon, England..
    Stitt, Alan W.
    Queens Univ Belfast, Ctr Med Expt, Belfast, Antrim, North Ireland..
    Vandenbrouke, Roosmarijn E.
    Univ Ghent, Dept Biomed Mol Biol, Ghent, Belgium.;VIB, VIB UGent Ctr Inflammat Res, Ghent, Belgium..
    Romero, Ignacio A.
    Open Univ, Sch Life Hlth & Chem Sci, Milton Keynes, Bucks, England..
    Campbell, Matthew
    Trinity Coll Dublin, Smurfit Inst Genet, Lincoln Pl Gate, Dublin 2, Ireland..
    Fricker, Gert
    Ruprecht Karls Univ Heidelberg, Inst Pharm & Mol Biotechnol, Heidelberg, Germany..
    Brodin, Birger
    Univ Copenhagen, Fac Hlth & Med Sci, Dept Pharm, Copenhagen, Denmark..
    Manninga, Heiko
    NEUWAY Pharma GmbH, Ludwig Erhard Allee 2, D-53175 Bonn, Germany..
    Gaillard, Pieter J.
    2 BBB Med BV, Leiden, Netherlands..
    Schwaninger, Markus
    Univ Lubeck, Inst Expt & Clin Pharmacol & Toxicol, Lubeck, Germany..
    Webster, Carl
    MedImmune, Antibody Discovery & Prot Engn, Cambridge, England..
    Wicher, Krzysztof B.
    Ossianix Inc, Stevenage, Herts, England..
    Khrestchatisky, Michel
    Aix Marseille Univ, NICN, CNRS, Marseille, France.;Fac Med Nord, Vect Horus, 51 Blvd Pierre Dramard, Marseille, France..
    Current research into brain barriers and the delivery of therapeutics for neurological diseases: a report on CNS barrier congress London, UK, 20172017In: Fluids and Barriers of the CNS, ISSN 2045-8118, E-ISSN 2045-8118, Vol. 14, article id 31Article, review/survey (Refereed)
    Abstract [en]

    This is a report on the CNS barrier congress held in London, UK, March 22-23rd 2017 and sponsored by Kisaco Research Ltd. The two 1-day sessions were chaired by John Greenwood and Margareta Hammarlund-Udenaes, respectively, and each session ended with a discussion led by the chair. Speakers consisted of invited academic researchers studying the brain barriers in relation to neurological diseases and industry researchers studying new methods to deliver therapeutics to treat neurological diseases. We include here brief reports from the speakers.

  • 33.
    Gustafsson, Sofia
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Syvänen, Stina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Eriksson, Olof
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Antoni, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging.
    Combined PET and microdialysis for in vivo estimation of drug blood-brain barrier transport and brain unbound concentrations2017In: NeuroImage, ISSN 1053-8119, E-ISSN 1095-9572, Vol. 155, p. 177-186Article in journal (Refereed)
    Abstract [en]

    Methods to investigate blood-brain barrier transport and pharmacologically active drug concentrations in the human brain are limited and data translation between species is challenging. Hence, there is a need to further develop the read-out of techniques like positron emission tomography ( PET) for studying neuropharmacokinetics. PET has a high translational applicability from rodents to man and measures total drug concentrations in vivo. The aim of the present study was to investigate the possibility of translating total drug concentrations, acquired through PET, to unbound concentrations, resembling those measured in the interstitial fluid by microdialysis sampling. Simultaneous PET scanning and brain microdialysis sampling were performed in rats throughout a 60 min infusion of [N-methyl-C-11] oxycodone in combination with a therapeutic dose of oxycodone and during a 60 min follow up period after the end of infusion. The oxycodone concentrations acquired with PET were converted into unbound concentrations by compensating for brain tissue binding and brain intracellular distribution, using the unbound volume of distribution in brain (Vu, brain), and were compared to microdialysis measurements of unbound concentrations. A good congruence between the methods was observed throughout the infusion. However, an accumulating divergence in the acquired PET and microdialysis data was apparent and became more pronounced during the elimination phase, most likely due to the passage of radioactive metabolites into the brain. In conclusion, the study showed that PET can be used to translate non-invasively measured total drug concentrations into unbound concentrations as long as the contribution of radiolabelled metabolites is minor or can be compensated for.

  • 34.
    Gustafsson, Sofia
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Gustavsson, Tobias
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Roshanbin, Sahar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Hultqvist, Greta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Syvänen, Stina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Blood-Brain Barrier Integrity in a Mouse Model of Alzheimer’s Disease With or Without Acute 3D6 Immunotherapy2018In: Neuropharmacology, ISSN 0028-3908, E-ISSN 1873-7064, Vol. 143, p. 1-9Article in journal (Refereed)
    Abstract [en]

    The blood-brain barrier (BBB) is suggested to be compromised in Alzheimer's disease (AD). The concomitant presence of vascular amyloid beta (AD) pathology, so called cerebral amyloid angiopathy (CAA), also predisposes impairment of vessel integrity. Additionally, immunotherapy against A beta may lead to further damage of the BBB. To what extent this affects the BBB passage of molecules is debated. The current study aimed to investigate BBB integrity to large molecules in transgenic mice displaying abundant A beta pathology and age matched wild type animals, with or without acute anti-A beta antibody treatment. Animals were administered a single i.v. injection of PBS or 3D6 (10 mg/kg), i.e. the murine version of the clinically investigated A beta antibody bapineuzumab, supplemented with [(125)]3D6. Three days post injections, a 4 kDa FITC and a 150 kDa Antonia Red dextran were administered i.v. to all animals. After termination, fluorescent detection in brain and serum was used for the calculation of dextran brain-to-blood concentration ratios. Further characterization of antibody fate and the presence of CAA were investigated using radioactivity measurements and Congo red staining. BBB passage of large molecules was equally low in wild type and transgenic mice, suggesting an intact BBB despite A beta pathology. Neither was the BBB integrity affected by acute 3D6 treatment. However, CAA was confirmed in the transgenes and local antibody accumulations were observed in the brain, indicating CAA-antibody interactions. The current study shows that independently of A beta pathology or acute 3D6 treatment, the BBB is intact, without extensive permeability to large molecules, including the 3D6 antibody.

  • 35.
    Gustafsson, Sofia
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Lindström, Veronica
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Ingelsson, Martin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Syvänen, Stina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Intact blood-brain barrier transport of small molecular drugs in animal models of amyloid beta and alpha-synuclein pathology2018In: Neuropharmacology, ISSN 0028-3908, E-ISSN 1873-7064, Vol. 128, p. 482-491Article in journal (Refereed)
    Abstract [en]

    Pathophysiological impairment of the neurovascular unit, including the integrity and dynamics of the blood-brain barrier (BBB), has been denoted both a cause and consequence of neurodegenerative diseases. Pathological impact on BBB drug delivery has also been debated. The aim of the present study was to investigate BBB drug transport, by determining the unbound brain-to-plasma concentration ratio (K-p,K-uu,K-brain), in aged A beta PP-transgenic mice, alpha-synuclein transgenic mice, and wild type mice. Mice were dosed with a cassette of five compounds, including digoxin, levofloxacin (1 mg/kg, s.c.), paliperidone, oxycodone, and diazepam (0.25 mg/kg, s.c.). Brain and blood were collected at 0.5,1, or 3 h after dosage. Drug concentrations were measured using LC-MS/MS. The total brain-to-plasma concentration ratio was calculated and equilibrium dialysis was used to determine the fraction of unbound drug in brain and plasma for all compounds. Together, these three measures were used to determine the Kp,uu,brain value. Despite A beta or alpha-synuclein pathology in the current animal models, no difference was observed in the extent of drug transport across the BBB compared to wild type animals for any of the compounds investigated. Hence, the present study shows that the concept of a leaking barrier within neurodegenerative conditions has to be interpreted with caution when estimating drug transport into the brain. The capability of the highly dynamic BBB to regulate brain drug exposure still seems to be intact despite the presence of pathology. (C) 2017 The Authors. Published by Elsevier Ltd.

  • 36.
    Gustafsson, Sofia
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Sehlin, Dag
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Lampa, Erik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, UCR-Uppsala Clinical Research Center.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Loryan, Irena
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Heterogeneous drug tissue binding in brain regions of rats, Alzheimer’s patients and controls: impact on translational drug development2019In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 9, article id 5308Article in journal (Refereed)
    Abstract [en]

    For preclinical and clinical assessment of therapeutically relevant unbound, free, brain concentrations, the pharmacokinetic parameter fraction of unbound drug in brain (fu,brain) is commonly used to compensate total drug concentrations for nonspecific brain tissue binding (BTB). As, homogenous BTB is assumed between species and in health and disease, rat BTB is routinely used. The impact of Alzheimer’s disease (AD) on drug BTB in brain regions of interest (ROI), i.e., fu,brain,ROI, is yet unclear. This study for the first time provides insight into regional drug BTB and the validity of employing rat fu,brain,ROI as a surrogate of human BTB, by investigating five marketed drugs in post-mortem tissue from AD patients (n = 6) and age-matched controls (n = 6). Heterogeneous drug BTB was observed in all within group comparisons independent of disease and species. The findings oppose the assumption of uniform BTB, highlighting the need of case-by-case evaluation of fu,brain,ROI in translational CNS research.

  • 37.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Active-Site Concentrations of Chemicals: Are They a Better Predictor of Effect than Plasma/Organ/Tissue Concentrations?2010In: Basic & Clinical Pharmacology & Toxicology, ISSN 1742-7835, E-ISSN 1742-7843, Vol. 106, no 3, p. 215-220Article, review/survey (Refereed)
    Abstract [en]

    Active-site concentrations can be defined as the concentrations of unbound, pharmacologically active substances at the site of action. In contrast, the total concentrations of the drug in plasma/organ/tissue also include the protein- or tissue-bound molecules that are pharmacologically inactive. Plasma and whole tissue concentrations are used as predictors of effects and side effects because of their ease of sampling, while the concentrations of unbound drug in tissue are more difficult to measure. However, with the introduction of microdialysis and subsequently developed techniques, it has become possible to test the free drug hypothesis. The brain is an interesting organ in this regard because of the presence of the blood-brain barrier with its tight junctions and active efflux and influx transporters. We have proposed that research into brain drug delivery be divided into three main areas: the rate of delivery (PS, CL(in)), the extent of delivery (K(p,uu)) and the non-specific affinity of the drug to brain tissue, described by the volume of distribution of unbound drug in the brain (V(u,brain)). In this way, the concentration of unbound drug at the target site can be estimated from the total brain concentration and the plasma concentration after measuring the fraction of unbound drug. Results so far fully support the theory that active site concentrations are the best predictors when active transport is present. However, there is an urgent need to collect more relevant data for predicting active site concentrations in tissues with active transporters in their plasma membranes.

  • 38.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    In vivo approaches to assessing the blood-brain barrier2014In: The blood-brain barrier (BBB) / [ed] Fricker G, Ott M, Mahringer A, Heidelberg New York Dordrecht London: Springer , 2014, p. 21-48Chapter in book (Refereed)
    Abstract [en]

    Methods for in vivo assessment of blood-brain barrier (BBB) transport are presented, with their advantages and disadvantages. The methods described are brain uptake index, the i.v. injection technique, in situ brain perfusion, brain efflux index, % injected dose, microdialysis, CSF sampling and positron emission tomography, and the combinatorial mapping of unbound drug partitioning across the BBB. The methods are put into a pharmacokinetic context by delineating the type of readings that they give, be it the rate of transport across the BBB or the extent of transport of total drug (unbound and bound), or of the unbound drug.

  • 39.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Microdialysis as an Important Technique in Systems Pharmacology: a Historical and Methodological Review2017In: AAPS Journal, ISSN 1550-7416, E-ISSN 1550-7416, Vol. 19, no 5, p. 1294-1303Article, review/survey (Refereed)
    Abstract [en]

    Microdialysis has contributed with very important knowledge to the understanding of target-specific concentrations and their relationship to pharmacodynamic effects from a systems pharmacology perspective, aiding in the global understanding of drug effects. This review focuses on the historical development of microdialysis as a method to quantify the pharmacologically very important unbound tissue concentrations and of recent findings relating to modeling microdialysis data to extrapolate from rodents to humans, understanding distribution of drugs in different tissues and disease conditions. Quantitative microdialysis developed very rapidly during the early 1990s. Method development was in focus in the early years including development of quantitative microdialysis, to be able to estimate true extracellular concentrations. Microdialysis has significantly contributed to the understanding of active transport at the blood-brain barrier and in other organs. Examples are presented where microdialysis together with modeling has increased the knowledge on tissue distribution between species, in overweight patients and in tumors, and in metabolite contribution to drug effects. More integrated metabolomic studies are still sparse within the microdialysis field, although a great potential for tissue and disease-specific measurements is evident.

  • 40.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Microdialysis in CNS PKPD research: Unraveling unbound concentrations2013In: Microdialysis in drug development / [ed] Müller M, New York Heidelberg Dordrecht London: Springer , 2013, p. 83-102Chapter in book (Refereed)
    Abstract [en]

    With the help of microdialysis sampling, we can describe pharmacokinetic processes of drug movement between blood and tissues, and can describe concentration profiles within a tissue over time. Not only this, but the fact that microdialysis measures the unbound, pharmacologically active drug concentration are unique features of the technique, not possible to obtain directly with any other method. These are the most valuable outcomes of the technique for PKPD studies, and are the basis for the description of the principles of CNS drug distribution and PKPD presented in this chapter. This chapter will cover microdialysis studies performed to investigate PK and PKPD relationships of the CNS, and also alternative methods to microdialysis when this technique does not work or when it is too slow in i.e. drug discovery.

  • 41.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Microdialysis in CNS PKPD Research: Unraveling Unbound Concentrations2013In: Microdialysis in Drug Development / [ed] Markus Müller, New York Heidelberg Dordrecht London: Springer, 2013, 1, p. 83-102Chapter in book (Refereed)
  • 42.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Pharmacokinetic concepts in brain drug delivery2014In: Drug delivery to the brain: Physiological concepts, methodologies and approaches / [ed] Hammarlund-Udenaes M, de Lange ECM, Thorn R, New York Heidelberg Dordrecht London: Springer , 2014, p. 127-162Chapter in book (Other academic)
    Abstract [en]

    This chapter presents the pharmacokinetic principles of blood-brain barrier (BBB) transport and the intra-brain distribution of drugs in order to provide a basis for understanding drug delivery to the brain from a clinically relevant perspective. The most important concentrations to measure when determining drug distribution are those of the unbound drug, because it is the unbound drug that causes the pharmacological effect by interacting with the target. Therefore, this chapter also discusses the pharmacokinetic basis, the kind of information provided, and the in vivo relevance of the methods used to obtain reliable, therapeutically useful estimates of brain drug delivery. The main factors governing drug distribution to the brain are the permeability of the BBB to the drug (influx clearance), the extent of nonspecific binding to brain tissue, and the efflux clearance of the drug. The ratio of the influx and efflux clearances provides an estimation of the extent of drug equilibration across the BBB, described by Kp,uu,brain. This parameter is important, as active uptake and/or efflux transporters influence the absolute brain concentrations of unbound drug in relation to those in plasma. The advantage of using Kp,uu,brain during the drug-discovery process lies in its ability to predict the potential success of drugs intended for action within the brain or, conversely, of those with few or no side effects in the brain.

  • 43.
    Hammarlund-Udenaes, Margareta
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Bredberg, Ulf
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Fridén, Markus
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Methodologies to assess brain drug delivery in lead optimization2009In: Current Topics in Medicinal Chemistry, ISSN 1568-0266, E-ISSN 1873-4294, Vol. 9, no 2, p. 148-162Article, review/survey (Refereed)
    Abstract [en]

    In the area of lead optimization for potential CNS-active drugs in medicinal chemistry, there is a great need for experimental methodologies that can generate data relevant to estimates of free (unbound) drug exposure within the CNS. The methods chosen have to be efficient and have to measure a pharmacologically relevant entity. The lack of methods for generating such data is probably linked with the lack of successful lead optimization strategies within CNS drug discovery. This article evaluates available methods for estimating drug delivery to the brain, and discusses the relevance of the methods from the perspective of CNS exposure to free drug. It is suggested that the extent of drug delivery is the most important investigative parameter, since permeability (rate of transfer) can vary within a relatively wide range and still allow effects within the CNS. Following this suggestion would shift the focus from the current way of thinking and could lead to the development of less lipophilic compounds than are currently being investigated. It is concluded that an extensive collection of quality data on brain drug delivery, transporter affinities and in vivo behavior is urgently required so as to be able to build relevant predictive in vitro and in silico models for the future. These models need to be much more focused on the asymmetry of active transport across the BBB than on permeability data.

  • 44.
    Hammarlund-Udenaes, Margareta
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Brouwer, Kim
    Nakashima, Emi
    Terasaki, Tetsuya
    Perspectives on a pharmacokinetics legend: C versus T (contributions over time)2013In: Journal of Pharmaceutical Sciences, ISSN 0022-3549, E-ISSN 1520-6017, Vol. 102, no 9, p. 2889-2894Article in journal (Other academic)
  • 45.
    Hammarlund-Udenaes, Margareta
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    de Lange, ElizabethLeiden University.Thorne, Robert G.University of Wisconsin Madison.
    Drug Delivery to the Brain: Physiological Concepts, Methodologies and Approaches2014Collection (editor) (Refereed)
  • 46.
    Hammarlund-Udenaes, Margareta
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Fridén, Markus
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Syvänen, Stina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Gupta, Anubha
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    On the rate and extent of drug delivery to the brain2008In: Pharmaceutical research, ISSN 0724-8741, E-ISSN 1573-904X, Vol. 25, no 8, p. 1737-1750Article, review/survey (Refereed)
    Abstract [en]

    To define and differentiate relevant aspects of blood-brain barrier transport and distribution in order to aid research methodology in brain drug delivery. Pharmacokinetic parameters relative to the rate and extent of brain drug delivery are described and illustrated with relevant data, with special emphasis on the unbound, pharmacologically active drug molecule. Drug delivery to the brain can be comprehensively described using three parameters: Kp,uu (concentration ratio of unbound drug in brain to blood), CLin (permeability clearance into the brain), and Vu,brain (intra-brain distribution). The permeability of the blood-brain barrier is less relevant to drug action within the CNS than the extent of drug delivery, as most drugs are administered on a continuous (repeated) basis. Kp,uu can differ between CNS-active drugs by a factor of up to 150-fold. This range is much smaller than that for log BB ratios (Kp), which can differ by up to at least 2,000-fold, or for BBB permeabilities, which span an even larger range (up to at least 20,000-fold difference). Methods that measure the three parameters Kp,uu, CLin, and Vu,brain can give clinically valuable estimates of brain drug delivery in early drug discovery programmes.

  • 47.
    Hu, Yang
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Gaillard, Pieter J.
    2-BBB Medicine B.V..
    De lange, Elizabeth C.M.
    Leiden University.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Targeted Brain Delivery of Methotrexate by Glutathione PEGylated Liposomes: How can the Formulation Make a Difference?2019In: European journal of pharmaceutics and biopharmaceutics, ISSN 0939-6411, E-ISSN 1873-3441, Vol. 139, p. 197-204Article in journal (Refereed)
    Abstract [en]

    The purpose of this study was to quantitatively investigate how conjugation of GSH to different liposomal formulations influence the brain delivery of methotrexate (MTX) in rats. GSH-PEG liposomal MTX based on hydrogenated soy phosphatidylcholine (HSPC) or egg yolk phosphatidylcholine (EYPC) and their corresponding PEG control liposomes were prepared. The brain delivery of MTX after intravenously administering free MTX, four liposomal formulations or free MTX + empty GSH-PEG-HSPC liposomes was evaluated by performing microdialysis in brain interstitial fluid and blood. Compared to free MTX with a steady-state unbound brain-toplasma concentration ratio (K-p,K-uu) of 0.10, PEG-HSPC liposomes did not affect the brain uptake of MTX, while PEG-EYPC liposomes improved the uptake (K-p,(uu) 1.5, p < 0.05). Compared to PEG control formulations, GSHPEG-HSPC liposomes increased brain delivery of MTX by 4-fold (K-p,(uu) 0.82, p < 0.05), while GSH-coating on PEG-EYPC liposomes did not result in a further enhancement in uptake. The co-administration of empty GSHPEG-HSPC liposomes with free MTX did not influence the uptake of MTX into the brain. This work showed that the brain-targeting effect of GSH-PEG liposomal MTX is highly dependent on the liposomal formulation that is combined with GSH, providing insights on formulation optimization of this promising brain delivery platform.

  • 48.
    Hu, Yang
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Gaillard, Pieter J.
    2 BBB Med BV, Leiden, Netherlands.
    Rip, Jaap
    Nanomi BV, Oldenzaal, Netherlands.
    De lange, Elizabeth C.M.
    Leiden Univ, Leiden Acad Ctr Drug Res, Div Syst Biomed & Pharmacol, Predict Pharmacol Grp, Leiden, Netherland.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences. Uppsala University, Science for Life Laboratory, SciLifeLab.
    In Vivo Quantitative Understanding of PEGylated Liposome’s Influence on Brain Delivery of Diphenhydramine2018In: Molecular Pharmaceutics, ISSN 1543-8384, E-ISSN 1543-8392, Vol. 15, no 12, p. 5493-5500Article in journal (Refereed)
    Abstract [en]

    Despite the promising features of liposomes as brain drug delivery vehicles, it remains uncertain how they influence the brain uptake in vivo. In order to gain a better fundamental understanding of the interaction between liposomes and the blood–brain barrier (BBB), it is indispensable to test if liposomes affect drugs with different BBB transport properties (active influx or efflux) differently. The aim of this study was to quantitatively evaluate how PEGylated (PEG) liposomes influence brain delivery of diphenhydramine (DPH), a drug with active influx at the BBB, in rats. The brain uptake of DPH after 30 min intravenous infusion of free DPH, PEG liposomal DPH, or free DPH + empty PEG liposomes was compared by determining the unbound DPH concentrations in brain interstitial fluid and plasma with microdialysis. Regular blood samples were taken to measure total DPH concentrations in plasma. Free DPH was actively taken up into the brain time-dependently, with higher uptake at early time points followed by an unbound brain-to-plasma exposure ratio (Kp,uu) of 3.0. The encapsulation in PEG liposomes significantly decreased brain uptake of DPH, with a reduction of Kp,uu to 1.5 (p < 0.05). When empty PEG liposomes were coadministered with free drug, DPH brain uptake had a tendency to decrease (Kp,uu 2.3), and DPH was found to bind to the liposomes. This study showed that PEG liposomes decreased the brain delivery of DPH in a complex manner, contributing to the understanding of the intricate interactions between drug, liposomes, and the BBB.

  • 49.
    Hu, Yang
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Fridén, Markus
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences. Department of Drug Metabolism and Pharmacokinetics, Early Respiratory, Inflammation and Autoimmunity, R&D Biopharmaceuticals, AstraZeneca R&D, Gothenburg, Sweden.
    Understanding the Influence of Nanocarrier-Mediated Brain Delivery on Therapeutic Performance Through Pharmacokinetic-Pharmacodynamic Modeling.2019In: Journal of Pharmaceutical Sciences, ISSN 0022-3549, E-ISSN 1520-6017, Vol. 108, no 10, p. 3425-3433Article in journal (Refereed)
    Abstract [en]

    This study aimed at evaluating how encapsulation in a regular nanocarrier (NC) (providing extended circulation time) or in a brain-targeting NC (providing prolonged circulation time and increased brain uptake) may influence the therapeutic index compared with the unformulated drug and to explore the key parameters affecting therapeutic performance using a model-based approach. Pharmacokinetic (PK) models were built with chosen PK parameters. For a scenario where central effect depends on area under the unbound brain concentration curve and peripheral toxicity relates to peak unbound plasma concentration, dose-effect and drug-side effect curves were constructed, and the therapeutic index was evaluated. Regular NC improved the therapeutic index compared with the unformulated drug due to reduced peripheral toxicity, while brain-targeting NC enhanced the therapeutic index by lowering peripheral toxicity and increasing central effect. Decreasing drug release rate or systemic clearance of NC with drug still encapsulated could increase the therapeutic index. Also, a drug with shorter half-life would therapeutically benefit more from a NC encapsulation. This work provides insights into how a NC for brain delivery should be optimized to maximize the therapeutic performance and is helpful to predict if and to what extent a drug with certain PK properties would obtain therapeutic benefit from nanoencapsulation.

  • 50.
    Hu, Yang
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Rip, Jaap
    Eyesiu Medicine B.V..
    Gaillard, Pieter
    Eyesiu Medicines B.V./2-BBB Medicine B.V,.
    De lange, Elizabeth
    Leiden University.
    Hammarlund-Udenaes, Margareta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences. Uppsala University, Science for Life Laboratory, SciLifeLab.
    The Impact of Liposomal Formulations on the Release and Brain Delivery of Methotrexate: : An In Vivo Microdialysis Study2017In: Journal of Pharmaceutical Sciences, ISSN 0022-3549, E-ISSN 1520-6017Article in journal (Refereed)
    Abstract [en]

    The impact of liposomal formulations on the in vivo release and brain delivery of methotrexate (MTX) was quantitatively assessed in rats. Two PEGylated liposomal MTX formulations based on hydrogenated soy phosphatidylcholine (HSPC) or egg-yolk phosphatidylcholine (EYPC) were prepared. The drug release and uptake into the brain after intravenous administration of both formulations were compared with unformulated MTX by determining the released, unbound MTX in brain and plasma using microdialysis. Total MTX concentrations in plasma were determined using regular blood sampling. The administration of both high- and low-dose EYPC liposomes resulted in 10 times higher extent of MTX release in plasma compared to that obtained from HSPC liposomes (p < 0.05). MTX itself possessed limited brain uptake with steady-state unbound brain-to-plasma concentration ratio (Kp,uu) of 0.10 ± 0.06. Encapsulation in HSPC liposomes did not affect MTX brain uptake (Kp,uu 0.11 ± 0.05). In contrast, EYPC liposomes significantly improved MTX brain delivery with a 3-fold increase of Kp,uu (0.28 ± 0.14 and 0.32 ± 0.13 for high- and low-dose EYPC liposomal MTX, respectively, p < 0.05). These results provide unique quantitative evidence that liposomal formulations based on different phospholipids can result in very different brain delivery of MTX

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