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  • 1. Abrahamsson, B
    et al.
    Lennernas, H
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy.
    Application of the biopharmaceutic classification system now and in the future2003In: Drug Bioavailability – Estimation of Solubility, Permeability, Absorption and Bioavailability, Wiley , 2003Chapter in book (Other scientific)
  • 2. Abrams, Pascale
    et al.
    Boquete, Hugo
    Fideleff, Hugo
    Feldt-Rasmussen, Ulla
    Jonsson, J
    Koltowska-Häggström, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Wilton, Patrick
    Abs, Roger
    GH replacement in hypopituitarism improves lipid profile and quality of life independently of changes in obesity variables2008In: European Journal of Endocrinology, ISSN 0804-4643, E-ISSN 1479-683X, Vol. 159, no 6, p. 825-832Article in journal (Refereed)
    Abstract [en]

    Objective: GH deficiency (GHD) in adults is characterized by elevated body mass index (BMI), increased waist girth (WG) and increased fat mass (FM). Information about how these indicators of obesity affect the lipid profile and quality of life (QoL) of GHD subjects is scarce. It is also unclear how changes in these indicators brought about by GH replacement influence lipids and QoL. Design and methods: Adult GHD Subjects from the Pfizer International Metabolic Database were grouped according to BMI (n = 291 with BMI < 25 kg/m(2), n = 372 with BMI 25-30 kg/m(2), n = 279 with BMI > 30 kg/m(2)), WG (n = 508 with normal WG, n = 434 with increased WG) and FM (n = 357) and according to changes in these variables after 1 year of GH replacement. Serum IGF-1 concentrations, lipid concentrations and QoL using the QoL Assessment of GHD in Adults questionnaire were assessed at baseline and after 1 year of treatment. Results: At baseline, total and low-density lipoprotein (LDL) cholesterol were similarly elevated in the BMI and WG groups, but high-density lipoprotein (HDL) cholesterol decreased and triglycerides increased with increasing BMI and WG. QoL was progressively poorer with increasing BMI and WG. After 1 year of GH replacement, total and LDL cholesterol and QoL improved in all BMI, WG and FM groups. Conclusions: Variables of obesity adversely affect the already unfavourable lipid profile in GHD Subjects by decreasing HDL cholesterol, but do not counteract the positive effect of GH replacement on LDL cholesterol. Similarly, QoL is influenced by obesity, but responds equally well to GH treatment independent of BMI, WG and FM.

  • 3.
    Abrantes, João
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Solms, Alexander
    Bayer, Berlin, Germany.
    Garmann, Dirk
    Bayer, Wuppertal, Germany.
    Nielsen, Elisabet I.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Jönsson, Siv
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Karlsson, Mats
    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 Pharmacy, Department of Pharmacy.
    Relationship between factor VIII activity, bleeds and individual characteristics in severe hemophilia A patientsIn: Article in journal (Refereed)
  • 4. Abs, Roger
    et al.
    Feldt-Rasmussen, Ulla
    Mattsson, Anders F
    Monson, John P
    Bengtsson, Bengt-Ake
    Goth, M I
    Wilton, Patrick
    Koltowska-Häggström, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Determinants of cardiovascular risk in 2589 hypopituitary GH-deficient adults - a KIMS database analysis.2006In: European Journal of Endocrinology, ISSN 0804-4643, E-ISSN 1479-683X, Vol. 155, no 1, p. 79-90Article in journal (Refereed)
    Abstract [en]

    Objective: The aim of the present study was to clarify the relationship between GH deficiency (GHD) andsome cardiovascular risk factors and to analyse the effect of GH replacement therapy in a large numberof patients over a prolonged period of time.Design: Data for analysis were retrieved from KIMS (Pfizer International Metabolic Database). Serumconcentrations of total cholesterol, high-density lipoprotein (HDL)-cholesterol, low-density lipoprotein(LDL)-cholesterol and triglycerides were obtained from 2589 patients at baseline and from 1206patients after 1 and 2 years of GH replacement therapy. Body mass index (BMI), waist and hip, restingblood pressure and body composition were also measured.Results: At baseline, the unfavourable effects of GHD were most obvious in the lipid profiledemonstrating elevated mean total and LDL-cholesterol, in the increased waist circumference and theelevated BMI. The cholesterol concentration, BMI and body composition were significantly adverselyaffected by a number of factors, including age, sex and the use of anti-epileptic drugs. The therapeuticeffect of GH was essentially uniform across the whole population. GH replacement reduced significantlythe mean total and LDL-cholesterol, the waist circumference and the fat mass and was maintainedduring 2 years.Conclusions: This analysis of a large number of patients confirmed that GHD adults present with anincreased cardiovascular risk. The sustained improvement of the adverse lipid profile and bodycomposition suggests that GH replacement therapy may reduce the risk of cardiovascular disease andthe premature mortality seen in hypopituitary patients with untreated GHD.

  • 5. Abs, Roger
    et al.
    Mattsson, Anders F
    Bengtsson, Bengt-Ke
    Feldt-Rasmussen, Ulla
    Goth, Miklos I
    Koltowska-Häggström, Maria
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy.
    Monson, John P
    Verhelst, Johan
    Wilton, Patrick
    Isolated growth hormone (GH) deficiency in adult patients: Baseline clinical characteristics and responses to GH replacement in comparison with hypopituitary patients. A sub-analysis of the KIMS database.2005In: Growth Horm IGF Res, ISSN 1096-6374, Vol. 15, no 5, p. 349-59Article in journal (Refereed)
  • 6.
    Adane, M.
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Gebre-Mariam, T
    Alderborn, Göran
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Frenning, Göran
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    The use of extragranular disintegrants in multiple-unit tablet formulations: effect on compressibility, compactibility and disintegration2007In: Journal of drug delivery science and technology, ISSN 1773-2247, Vol. 17, no 4, p. 279-284Article in journal (Refereed)
    Abstract [en]

    Multiple-unit tablets formed from mixtures of microcrystalline cellulose pellets and disintegrants (Ac-Di-Sol, Primojel or Kollidon CL) by compaction were investigated with the aim of controlling tablet tensile strength and disintegration time. The effects of pellet porosity, compaction pressure, and type and amount of disintegrant were studied. Primojel made the pellets less prone to deformation during compression, while the other two disintegrants had very minor effects on the compression behavior. Ac-Di-Sol and Primojel generally increased the tablet tensile strength, whereas the effect of Kollidon CL was dependent on the initial pellet porosity. Kollidon CL was found to significantly reduce the disintegration time, but the other two disintegrants had variable efficacy, and for the low-porosity pellets significantly increased the disintegration time. These results are interpreted as resulting from the interplay between the mechanical characteristics of the pellets and the mechanisms of action of the disintegrants.

  • 7.
    Adolfsson, A
    et al.
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy.
    Caramella, C
    Nystrom, C
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy.
    The effect of milling and addition of dry binder on the interparticulate bonding mechanisms in sodium chloride tablets1998In: Int J Pharmaceutics, Vol. 160, p. 187-Article in journal (Refereed)
  • 8.
    Adolfsson, A
    et al.
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy.
    Gustafsson, C
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy.
    Nystrom, C
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy.
    Use of tablet tensile strength adjusted for surface area and mean interparticulate distance to evaluate dominating bonding mechanisms1999In: DRUG DEV IND PHARMACY, Vol. 25, p. 753-Article in journal (Refereed)
  • 9.
    Adolfsson, A
    et al.
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy.
    Nystrom, C
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy.
    Tablet strength, porosity, elasticity and solid state structure of tablets compressed at high loads1996In: INTERNATIONAL JOURNAL OF PHARMACEUTICS, Vol. 132, p. 95-Article in journal (Refereed)
  • 10.
    Adolfsson, A
    et al.
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy.
    Olsson, H
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy.
    Nystrom, C
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy.
    Effect of particle size and compaction load on interparticulate bonding structure for some pharmaceutical materials studied by compaction and strength characterisation in butanol1997In: EUROPEAN JOURNAL OF PHARMACEUTICS AND BIOPHARMACEUTICS, Vol. 44, p. 243-Article in journal (Refereed)
  • 11.
    Adolfsson, Åsa
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy.
    Mechanical strength of pharmaceutical compacts: Importance of material characteristics, particle characteristics and compaction pressure on interparticulate bonding structure1998Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Factors considered important for the interparticulate bonding structure and mechanical strength of pharmaceutical compacts were studied in this thesis.

    Fractures appear to propagate mainly around rather than through grains during strength testing. Large deviations from theoretical strength values in addition to an effect of particle size were thus obtained when compaction was performed to zero porosity or obtained by extrapolation to zero porosity. When high compaction loads were used, the excess energy was to a large extent used for elastic recovery and/or alteration of the solid-state structure.

    Filtering out of weak distance forces (intermolecular forces) by compaction in a liquid with a sufficiently high dielectric constant appears to provide reliable information on interparticulate bonding mechanisms. The best correlation between physiochemical properties of the liquids and the gradual decrease in tensile strength of the compacts was achieved using the dielectric constant. The weak distance forces appeared to be screened out when the liquid compaction medium had a dielectric constant of 18. The remaining tensile strength was then believed to be the result of interparticulate bonding by solid bridges for most materials. However, for most pharmaceutical materials, weak distance forces seem to dominate. Of all the materials tested, solid bridges seemed to be the most important bonding mechanism for sodium and potassium chloride. Increasing the particle size and compaction pressure of materials with the capacity to form solid bridges seemed to facilitate the bond formation process. Addition of a dry binder or milling the particles counteracted the formation of solid bridges, probably by reducing the concentration of stress at certain points in the compact, a prerequisite for the establishment of solid bridges.

    Both the tablet surface area and the interparticulate distance may affect the proportion of external surface area participating in interparticulate bonding. For materials prone to develop solid bridges, the actual surface area involved in bond formation is more important than the space between the particles, i.e. compensation of the tensile strength of a tablet for the surface area and the mean interparticulate distance will probably not reflect the nature of the dominating bond type. However, for the other materials, ranking of the materials according to tensile strength adjusted for surface area and mean interparticulate distance gave a reflection of dominating interparticulate bonding type.

  • 12.
    Afzelius, Lovisa
    et al.
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Medicinal Chemistry. Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Medicinal Chemistry. OrgFarmKemi.
    Raubacher, Florian
    Karlen, Anders
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Medicinal Chemistry. Department of Pharmacy. OrgFarmKemi.
    Jørgensen, Flemming Steen
    Andersson, Tommy B
    Masimirembwa, Collen M
    Zamora, Ismael
    Structural analysis of CYP2C9 and CYP2C5 and an evaluation of commonly used molecular modeling techniques.2004In: Drug Metab Dispos, ISSN 0090-9556, Vol. 32, no 11, p. 1218-29Article in journal (Refereed)
  • 13.
    Ahlin, Gustav
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    In vitro and in silico prediction of drug-drug interactions with transport proteins2009Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Drug transport across cells and cell membranes in the human body is crucial for the pharmacological effect of drugs. Active transport governed by transport proteins plays an important role in this process. A vast number of transport proteins with a wide tissue distribution have been identified during the last 15 years. Several important examples of their role in drug disposition and drug-drug interactions have been described to date. Investigation of drug-drug interactions at the transport protein level are therefore of increasing interest to the academic, industrial and regulatory research communities.

    The gene expression of transport proteins involved in drug transport was investigated in the jejunum, liver, kidney and colon to better understand their influence on the ADMET properties of drugs. In addition, the gene and protein expression of transport proteins in cell lines, widely used for predictions of drug transport and metabolism, was examined.

    The substrate and inhibitor heterogeneity of many transport proteins makes it difficult to foresee whether the transport proteins will cause drug-drug interactions. Therefore, in vitro assays for OCT1 and OATP1B1, among the highest expressed transport proteins in human liver, were developed to allow investigation of the inhibitory patterns of these proteins. These assays were used to investigate two data sets, consisting of 191 and 135 registered drugs and drug-like molecules for the inhibition of OCT1 and OATP1B1, respectively. Numerous new inhibitors of the transport proteins were identified in the data sets and the properties governing inhibition were determined. Further, antidepressant drugs and statins displayed strong inhibition of OCT1 and OATP1B1, respectively. The inhibition data was used to develop predictive in silico models for each of the two transport proteins.

    The highly polymorphic nature of some transport proteins has been shown to affect drug response and may lead to an increased risk of drug-drug interactions, and therefore, the OCT1 in vitro assay was used to study the effect of common genetic variants of OCT1 on drug inhibition and drug-drug interactions. The results indicated that OCT1 variants with reduced function were more susceptible to inhibition. Further, a drug-drug interaction of potential clinical significance in the genetic OCT1 variant M420del was proposed.

    In summary, gene expression of transport proteins was investigated in human tissues and cell lines. In vitro assays for two of the highest expressed liver transport proteins were used to identify previously unknown SLC transport protein inhibitors and to develop predictive in silico models, which may detect previously known drug-drug interactions and enable new ones to be identified at the transport protein level. In addition, the effect of genetic variation on inhibition of the OCT1 was investigated.

    List of papers
    1. Expression of thirty-six drug transporter genes in human intestine, liver, kidney, and organotypic cell lines
    Open this publication in new window or tab >>Expression of thirty-six drug transporter genes in human intestine, liver, kidney, and organotypic cell lines
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    2007 (English)In: Drug Metabolism And Disposition, ISSN 0090-9556, E-ISSN 1521-009X, Vol. 35, no 8, p. 1333-1340Article in journal (Refereed) Published
    Abstract [en]

    This study was designed to quantitatively assess the mRNA expression of 36 important drug transporters in human jejunum, colon, liver, and kidney. Expression of these transporters in human organs was compared with expression in commonly used cell lines (Caco-2, HepG2, and Caki-1) originating from these organs to assess their value as in vitro transporter system models, and was also compared with data obtained from the literature on expression in rat tissues to assess species differences. Transporters that were highly expressed in the intestine included HPT1, PEPT1, BCRP, MRP2, and MDR1, whereas, in the liver, OCT1, MRP2, OATP-C, NTCP and BSEP were the main transporters. In the kidney, OAT1 was expressed at the highest levels, followed by OAT3, OAT4, MCT5, MDR1, MRP2, OCT2, and OCTN2. The best agreement between human tissue and the representative cell line was observed for human jejunum and Caco-2 cells. Expression in liver and kidney ortholog cell lines was not correlated with that in the associated tissue. Comparisons with rat transporter gene expression revealed significant species differences. Our results allowed a comprehensive quantitative comparison of drug transporter expression in human intestine, liver, and kidney. We suggest that it would be beneficial for predictive pharmacokinetic research to focus on the most highly expressed transporters. We hope that our comparison of rat and human tissue will help to explain the observed species differences in in vivo models, increase understanding of the impact of active transport processes on pharmacokinetics and distribution, and improve the quality of predictions from animal studies to humans.

    Keywords
    Urinary system, Digestive system, Cell line, Established cell line, In vitro, Kidney, Liver, Gut, Human, Genetics, Gene, Carrier protein, Drug
    National Category
    Pharmaceutical Sciences
    Identifiers
    urn:nbn:se:uu:diva-11385 (URN)10.1124/dmd.107.014902 (DOI)000248200000013 ()17496207 (PubMedID)
    Available from: 2007-09-11 Created: 2007-09-11 Last updated: 2018-01-12Bibliographically approved
    2. Endogenous Gene and Protein Expression of Drug Transporting Proteins in Cell Lines Routinely used in Drug Discovery Programs
    Open this publication in new window or tab >>Endogenous Gene and Protein Expression of Drug Transporting Proteins in Cell Lines Routinely used in Drug Discovery Programs
    Show others...
    2009 (English)In: Drug Metabolism And Disposition, ISSN 0090-9556, E-ISSN 1521-009X, Vol. 37, no 12, p. 2275-2283Article in journal (Refereed) Published
    Abstract [en]

    The aim of this study was to investigate the gene and protein expression profiles of important drug transporting proteins in human cell lines commonly used for studies of drug transport mechanisms. Human cell lines used to transiently or stably express single transporters (HeLa, HEK293) and leukaemia cell lines used to study drug resistance by ABC-transporters (HL-60, K562) were investigated, and compared with organotypic cell lines (HepG2, Saos-2, Caco-2 and Caco-2 TC7). For gene expression studies, real-time PCR was used, while monospecific polyclonal antibodies were generated and used to investigate protein expression by immunohistochemistry. Thirty-six transporters were studied for gene expression and nine for protein expression. The antibodies were validated using expression patterns in human tissues. Finally, the function of one ubiquitously expressed transporter, MCT1; SLC16A1 was investigated using 14C-lactic acid as a substrate. In general, the adherent cell lines (HeLa, HEK293) displayed low transporter expression and the expression patterns were barely affected by transfection. The leukaemia cell lines (K562, HL-60) and Saos-2 also had low endogenous transporter expression, while the organotypic cell lines (HepG2 and Caco-2) showed higher expression of some transporters. Comparison of gene and protein expression profiles gave poor correlations, but better agreement was obtained for antibodies with a good validation score, indicating that antibody quality was a significant variable. Importantly, the monocarboxylic acid transporting protein MCT1 was significantly expressed in all, and functional in most of the cell lines, indicating that MCT1 may be a confounding factor when the transport of small anionic drugs is investigated.

    Keywords
    Cell lines, Caco-2, HEK293, HeLa, Saos-2, HL-60, K562, HepG2, Gene expression, Protein expression, MCT1
    National Category
    Pharmaceutical Sciences
    Research subject
    Biopharmaceutics; Pharmaceutics
    Identifiers
    urn:nbn:se:uu:diva-107571 (URN)10.1124/dmd.109.028654 (DOI)000271935200002 ()19741037 (PubMedID)
    Available from: 2009-08-17 Created: 2009-08-17 Last updated: 2018-01-13Bibliographically approved
    3. Structural requirements for drug inhibition of the liver specific human organic cation transport protein 1
    Open this publication in new window or tab >>Structural requirements for drug inhibition of the liver specific human organic cation transport protein 1
    Show others...
    2008 (English)In: Journal of Medicinal Chemistry, ISSN 0022-2623, E-ISSN 1520-4804, Vol. 51, no 19, p. 5932-5942Article in journal (Refereed) Published
    Abstract [en]

    The liver-specific organic cation transport protein (OCT1; SLC22A1) transports several cationic drugs including the antidiabetic drug metformin and the anticancer agents oxaliplatin and imatinib. In this study, we explored the chemical space of registered oral drugs with the aim of studying the inhibition pattern of OCT1 and of developing predictive computational models of OCT1 inhibition. In total, 191 structurally diverse compounds were examined in HEK293-OCT1 cells. The assay identified 47 novel inhibitors and confirmed 15 previously known inhibitors. The enrichment of OCT1 inhibitors was seen in several drug classes including antidepressants. High lipophilicity and a positive net charge were found to be the key physicochemical properties for OCT1 inhibition, whereas a high molecular dipole moment and many hydrogen bonds were negatively correlated to OCT1 inhibition. The data were used to generate OPLS-DA models for OCT1 inhibitors; the final model correctly predicted 82% of the inhibitors and 88% of the noninhibitors of the test set.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-86815 (URN)10.1021/jm8003152 (DOI)000259760500010 ()18788725 (PubMedID)
    Available from: 2008-12-08 Created: 2008-12-08 Last updated: 2017-12-14Bibliographically approved
    4. Genotype-dependent effects of inhibitors of the organic cation transporter, OCT1:: predictions of metformin interactions
    Open this publication in new window or tab >>Genotype-dependent effects of inhibitors of the organic cation transporter, OCT1:: predictions of metformin interactions
    Show others...
    2011 (English)In: The Pharmacogenomics Journal, ISSN 1470-269X, E-ISSN 1473-1150, Vol. 11, no 6, p. 400-411Article in journal (Refereed) Published
    Abstract [en]

    Common genetic variants of the liver-specific human organic cation transporter 1 (OCT1; SLC22A1) have reduced transport capacity for substrates such as the antidiabetic drug metformin. The effect of the reduced OCT1 function on drug interactions associated with OCT1 has not been investigated and was, therefore, the focus of the study presented here. HEK293 cells expressing human OCT1-reference or the variants R61C, V408M, M420del and G465R were first used to study the kinetics and inhibition pattern of the OCT1 substrate 4-(4-(dimethylamino)styryl)-N-methylpyridinium (ASP(+)). In the second part OCT1-mediated (14)C-metformin uptake was studied in the presence of drugs administered concomitantly with metformin. Transport studies using ASP(+) showed that the function of the variants decreased in the following order: OCT1-reference = V408M = M420del >R61C > >G465R. Variants M420del and R61C were more sensitive to drug inhibition, with IC(50) values up to 23 times lower than those of the OCT1-reference. Uptake studies using (14)C-metformin were in qualitative agreement with those using ASP(+), with the exception that a larger reduction in transport capacity was observed for M420del. Concomitantly administered drugs, such as verapamil and amitriptyline, revealed potential drug-drug interactions at clinical plasma concentrations of metformin for OCT1-M420del.

    Keywords
    OCT1, polymorphism, metformin, drug-drug intaeractions, transport protein
    National Category
    Pharmaceutical Sciences
    Research subject
    Biopharmaceutics; Pharmaceutics
    Identifiers
    urn:nbn:se:uu:diva-107572 (URN)10.1038/tpj.2010.54 (DOI)000297506500003 ()
    Available from: 2009-08-17 Created: 2009-08-17 Last updated: 2018-01-13Bibliographically approved
    5. In Vitro and In Silico Strategies to Identify OATP1B1 Inhibitors and Predict Clinical Drug-Drug Interactions
    Open this publication in new window or tab >>In Vitro and In Silico Strategies to Identify OATP1B1 Inhibitors and Predict Clinical Drug-Drug Interactions
    Show others...
    2012 (English)In: Pharmaceutical research, ISSN 0724-8741, E-ISSN 1573-904X, Vol. 29, no 2, p. 411-426Article in journal (Other academic) Published
    Abstract [en]

    To establish in vitro and in silico models that predict clinical drug-drug interactions (DDIs) with the OATP1B1 (SLCO1B1) transporter. The inhibitory effect of 146 drugs and drug-like compounds on OATP1B1-mediated transport was studied in HEK293 cells. A computational model was developed to predict OATP1B1 inhibition. Concentration-dependent effects were investigated for six compounds; clinical DDIs were predicted by calculating change in exposure (i.e. R-values) in eight different ways. Sixty-five compounds were identified as OATP1B1 inhibitors at 20 mu M. The computational model predicted the test set with 80% accuracy for inhibitors and 91% for non-inhibitors. In vitro-in vivo comparisons underscored the importance of using drugs with known clinical effects as references. Thus, reference drugs, cyclosporin A, gemfibrozil, and fenofibrate, provided an inhibition interval to which three antiviral drugs, atazanavir, lopinavir, and amprenavir, could be compared and their clinical DDIs with OATP1B1 classified. Twenty-two new OATP1B1 inhibitors were identified, a predictive OATP1B1 inhibition in silico model was developed, and successful predictions of clinical DDIs were obtained with OATP1B1.

    Keywords
    in silico, in vitro-in vivo extrapolation, inhibition, MRP2, OATP1B1
    National Category
    Pharmaceutical Sciences
    Research subject
    Biopharmaceutics; Pharmaceutics
    Identifiers
    urn:nbn:se:uu:diva-107573 (URN)10.1007/s11095-011-0564-9 (DOI)000299506700007 ()
    Available from: 2009-08-17 Created: 2009-08-17 Last updated: 2018-01-13Bibliographically approved
  • 14.
    Ahlin, Gustav
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Chen, L
    Department of Biopharmaceutical Sciences, University of California San Francisco, San Francisco, California, USA.
    Lazorova, Lucia
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Chen, Ying
    Department of Biopharmaceutical Sciences, University of California San Francisco, San Francisco, California, USA.
    Ianculescu, Alexandra G.
    Department of Biopharmaceutical Sciences, University of California San Francisco, San Francisco, California, USA.
    Davis, Robert L.
    3Center for Health Research Southeast, Kaiser Permanente, Atlanta, USA.
    Giacomini, Kathleen M.
    Department of Biopharmaceutical Sciences, University of California San Francisco, San Francisco, California, USA.
    Artursson, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Genotype-dependent effects of inhibitors of the organic cation transporter, OCT1:: predictions of metformin interactions2011In: The Pharmacogenomics Journal, ISSN 1470-269X, E-ISSN 1473-1150, Vol. 11, no 6, p. 400-411Article in journal (Refereed)
    Abstract [en]

    Common genetic variants of the liver-specific human organic cation transporter 1 (OCT1; SLC22A1) have reduced transport capacity for substrates such as the antidiabetic drug metformin. The effect of the reduced OCT1 function on drug interactions associated with OCT1 has not been investigated and was, therefore, the focus of the study presented here. HEK293 cells expressing human OCT1-reference or the variants R61C, V408M, M420del and G465R were first used to study the kinetics and inhibition pattern of the OCT1 substrate 4-(4-(dimethylamino)styryl)-N-methylpyridinium (ASP(+)). In the second part OCT1-mediated (14)C-metformin uptake was studied in the presence of drugs administered concomitantly with metformin. Transport studies using ASP(+) showed that the function of the variants decreased in the following order: OCT1-reference = V408M = M420del >R61C > >G465R. Variants M420del and R61C were more sensitive to drug inhibition, with IC(50) values up to 23 times lower than those of the OCT1-reference. Uptake studies using (14)C-metformin were in qualitative agreement with those using ASP(+), with the exception that a larger reduction in transport capacity was observed for M420del. Concomitantly administered drugs, such as verapamil and amitriptyline, revealed potential drug-drug interactions at clinical plasma concentrations of metformin for OCT1-M420del.

  • 15.
    Ahlin, Gustav
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Hilgendorf, Constanze
    AstraZeneca R&D, Mölndal.
    Karlsson, Johan
    AstraZeneca R&D, Mölndal, Sweden.
    Al-Khalili Szigyarto, Cristina
    Department of Proteomics, The Royal Institute of Technology, Stockholm, Sweden.
    Uhlén, Mathias
    Department of Proteomics, The Royal Institute of Technology, Stockholm, Sweden.
    Artursson, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Endogenous Gene and Protein Expression of Drug Transporting Proteins in Cell Lines Routinely used in Drug Discovery Programs2009In: Drug Metabolism And Disposition, ISSN 0090-9556, E-ISSN 1521-009X, Vol. 37, no 12, p. 2275-2283Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to investigate the gene and protein expression profiles of important drug transporting proteins in human cell lines commonly used for studies of drug transport mechanisms. Human cell lines used to transiently or stably express single transporters (HeLa, HEK293) and leukaemia cell lines used to study drug resistance by ABC-transporters (HL-60, K562) were investigated, and compared with organotypic cell lines (HepG2, Saos-2, Caco-2 and Caco-2 TC7). For gene expression studies, real-time PCR was used, while monospecific polyclonal antibodies were generated and used to investigate protein expression by immunohistochemistry. Thirty-six transporters were studied for gene expression and nine for protein expression. The antibodies were validated using expression patterns in human tissues. Finally, the function of one ubiquitously expressed transporter, MCT1; SLC16A1 was investigated using 14C-lactic acid as a substrate. In general, the adherent cell lines (HeLa, HEK293) displayed low transporter expression and the expression patterns were barely affected by transfection. The leukaemia cell lines (K562, HL-60) and Saos-2 also had low endogenous transporter expression, while the organotypic cell lines (HepG2 and Caco-2) showed higher expression of some transporters. Comparison of gene and protein expression profiles gave poor correlations, but better agreement was obtained for antibodies with a good validation score, indicating that antibody quality was a significant variable. Importantly, the monocarboxylic acid transporting protein MCT1 was significantly expressed in all, and functional in most of the cell lines, indicating that MCT1 may be a confounding factor when the transport of small anionic drugs is investigated.

  • 16.
    Ahlin, Gustav
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Karlsson, Johan
    Pedersen, Jenny M
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Gustavsson, Lena
    Larsson, Rolf
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Pharmacology.
    Matsson, Pär
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Norinder, Ulf
    Bergström, Christel A S
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Artursson, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Structural requirements for drug inhibition of the liver specific human organic cation transport protein 12008In: Journal of Medicinal Chemistry, ISSN 0022-2623, E-ISSN 1520-4804, Vol. 51, no 19, p. 5932-5942Article in journal (Refereed)
    Abstract [en]

    The liver-specific organic cation transport protein (OCT1; SLC22A1) transports several cationic drugs including the antidiabetic drug metformin and the anticancer agents oxaliplatin and imatinib. In this study, we explored the chemical space of registered oral drugs with the aim of studying the inhibition pattern of OCT1 and of developing predictive computational models of OCT1 inhibition. In total, 191 structurally diverse compounds were examined in HEK293-OCT1 cells. The assay identified 47 novel inhibitors and confirmed 15 previously known inhibitors. The enrichment of OCT1 inhibitors was seen in several drug classes including antidepressants. High lipophilicity and a positive net charge were found to be the key physicochemical properties for OCT1 inhibition, whereas a high molecular dipole moment and many hydrogen bonds were negatively correlated to OCT1 inhibition. The data were used to generate OPLS-DA models for OCT1 inhibitors; the final model correctly predicted 82% of the inhibitors and 88% of the noninhibitors of the test set.

  • 17. Ahmed, Sara
    et al.
    Schwartz, Carolyn
    Ring, Lena
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Sprangers, Mirjam A. G.
    Applications of health-related quality of life for guiding health care: advances in response shift research2009In: Journal of Clinical Epidemiology, ISSN 0895-4356, E-ISSN 1878-5921, Vol. 62, no 11, p. 1115-1117Article in journal (Refereed)
  • 18.
    Ahnfelt, Emelie
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    In vitro evaluation of formulations used in the treatment of hepatocellular carcinoma2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Hepatocellular carcinoma (HCC) causes ~ 600,000 deaths annually, making it the second most deadly cancer form. HCC is classified into five stages and for the intermediate HCC treatment, the two most commonly used drug delivery systems (DDSs) are lipiodol-based emulsions and drug-eluting beads. The aims of this thesis were to develop in vitro methods suitable for studying these DDSs. It is important to investigate the release mechanisms and release rates with relevant in vitro methods, as this can improve the understanding of the in vivo performance. Miniaturized in vitro methods with sample reservoirs separated from the release medium by a diffusion barrier were developed and shown to be suitable for studying drug release from particle DDSs (Paper I). In Paper II these methods were further developed and used to study the release of doxorubicin (DOX) from the clinically used drug-eluting beads. DOX release rates were affected by the method set-up and the characteristics of the release medium. The choice of method and volume of release medium could improve the in vivo-likeness of the in vitro release profiles. Applied theoretical models suggested a film-controlled type of DOX release mechanism from the beads when self-aggregation, DOX-bead interaction, and DOX deprotonation were taken into account.

    A micropipette-assisted microscopy method was used to further improve the understanding of the release mechanism of amphiphilic molecules from the beads (Paper III). A detailed analysis suggested an internal depletion-layer model dependent on molecular self-aggregation for the release. It was further suggested that a simple ion-exchange mechanism is unrealistic in physiological conditions.

    The important pharmaceutical factors for the emulsion-based formulations were investigated in Paper IV. DOX solubility, lipid phase distribution, and emulsion stability increased when the contrast agent iohexol was added. Also, an increase in release half-life (h) was observed from emulsions with iohexol.

    The in vitro methods and theoretical models presented in this thesis can be used during development and optimization of future DDSs.

    List of papers
    1. A miniaturized in vitro release method for investigating drug-release mechanisms
    Open this publication in new window or tab >>A miniaturized in vitro release method for investigating drug-release mechanisms
    2015 (English)In: International Journal of Pharmaceutics, ISSN 0378-5173, E-ISSN 1873-3476, Vol. 486, no 1-2, p. 339-349Article in journal (Refereed) Published
    Abstract [en]

    We have evaluated a miniaturized in vitro method, based on the mDISS Profiler (TM) technique that enables on-line monitoring of drug release from a 21 mu l sample with 10 ml of release medium. Four model drugs in eight clinically used formulations, including both solid and non-solid drug delivery systems, were investigated. The acquired data were compared with historical in vitro release data from the same formulations. Use of the Weibull function to describe the in vitro drug-release profiles allowed discrimination between the selected formulations with respect to the drug-release mechanisms. Comparison of the release data from the same formulation in different in vitro set-ups showed that the methodology used can affect the mechanism of in vitro release. We also evaluated the ability of the in vitro methods to predict in vivo activity by comparing simulated plasma concentration-time profiles acquired from the application of the biopharmaceutical software GI-Sim to the in vitro observations. In summary, the simulations based on the miniaturized-method release data predicted the plasma profiles as well as or more accurately than simulations based on the historical release data in 71% of the cases and this miniaturized in vitro method appears to be applicable for both solid and non-solid formulations.

    Keywords
    In vitro release methods, Release mechanisms, Weibull function, GI-Sim, In vivo prediction
    National Category
    Pharmaceutical Sciences
    Identifiers
    urn:nbn:se:uu:diva-255064 (URN)10.1016/j.ijpharm.2015.03.076 (DOI)000353999100037 ()25843760 (PubMedID)
    Available from: 2015-06-22 Created: 2015-06-12 Last updated: 2018-10-30Bibliographically approved
    2. In Vitro Release Mechanisms of Doxorubicin From a Clinical Bead Drug-Delivery System
    Open this publication in new window or tab >>In Vitro Release Mechanisms of Doxorubicin From a Clinical Bead Drug-Delivery System
    2016 (English)In: Journal of Pharmaceutical Sciences, ISSN 0022-3549, E-ISSN 1520-6017, Vol. 105, no 11, p. 3387-3398Article in journal (Refereed) Published
    Abstract [en]

    The release rate of doxorubicin (DOX) from the drug-delivery system (DDS), DC Bead, was studied by 2 miniaturized in vitro methods: free-flowing and sample reservoir. The dependencies of the release mechanisms on in vitro system conditions were investigated experimentally and by theoretical modeling. An inverse relationship was found between release rates and bead size, most likely due to the greater total surface area. The release rates correlated positively with temperature, release medium volume, and buffer strength, although the release medium volume had larger effect than the buffer strength. The sample reservoir method generated slower release rates, which described the in vivo release profile more accurately than the free-flowing method. There was no difference between a pH of 6.3 or 7.4 on the release rate, implying that the slightly acidic tumor microenvironment is less importance for drug release. A positive correlation between stirring rate and release rate for all DDS sizes was observed, which suggests film controlled release. Theoretical modeling highlighted the influence of local equilibrium of protonation, self-aggregation, and bead material interactions of DOX. The theoretical release model might describe the observed larger sensitivity of the release rate to the volume of the release medium compared to buffer strength. A combination of miniaturized in vitro methods and theoretical modeling are useful to identify the important parameters and processes for DOX release from a micro gel-based DDS.

    Keywords
    controlled release, diffusion, dissolution, dissolution rate, drug-delivery systems, in vitro models, mathematical model, microspheres
    National Category
    Pharmaceutical Sciences
    Identifiers
    urn:nbn:se:uu:diva-311211 (URN)10.1016/j.xphs.2016.08.011 (DOI)000388268200018 ()27663384 (PubMedID)
    Funder
    Swedish Research Council, 521-2011-373
    Available from: 2016-12-22 Created: 2016-12-22 Last updated: 2018-10-30Bibliographically approved
    3. Single bead investigation of a clinical drug delivery system – a novel release mechanism
    Open this publication in new window or tab >>Single bead investigation of a clinical drug delivery system – a novel release mechanism
    Show others...
    2018 (English)In: Journal of Controlled Release, ISSN 0168-3659, E-ISSN 1873-4995, Vol. 292, p. 235-247Article in journal (Refereed) Published
    Abstract [en]

    Microgels, such as polymeric hydrogels, are currently used as drug delivery devices (DDSs) for chemotherapeutics and/or unstable drugs. The clinical DDS DC bead® was studied with respect to loading and release, measured as relative bead-volume, of six amphiphilic molecules in a micropipette-assisted microscopy method. Theoretical models for loading and release was used to increase the mechanistic understanding of the DDS.

    It was shown that equilibrium loading was independent of amphiphile concentration. The loading model showed that the rate-determining step was diffusion of the molecule from the bulk to the bead surface (‘film control’). Calculations with the developed and applied release model on the release kinetics were consistent with the observations, as the amphiphiles distribute unevenly in the bead. The rate determining step of the release was the diffusion of the amphiphile molecule through the developed amphiphile-free depletion layer. The release rate is determined by the diffusivity and the tendency for aggregation of the amphiphile where a weak tendency for aggregation (i.e. a large cacb) lead to faster release. Salt was necessary for the release to happen, but at physiological concentrations the entry of salt was not rate-determining. This study provides valuable insights into the loading to and release from the DDS. Also, a novel release mechanism of the clinically used DDS is suggested.

    Keywords
    Microgel, Drug delivery, Release mechanism
    National Category
    Pharmaceutical Sciences
    Identifiers
    urn:nbn:se:uu:diva-360988 (URN)10.1016/j.jconrel.2018.11.011 (DOI)000452348100019 ()30419268 (PubMedID)
    Funder
    Swedish Research Council, 521-2011-373
    Available from: 2018-09-20 Created: 2018-09-20 Last updated: 2019-01-21Bibliographically approved
    4. In vitro evaluation of lipiodol-based emulsions in clinical use
    Open this publication in new window or tab >>In vitro evaluation of lipiodol-based emulsions in clinical use
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Pharmaceutical Sciences
    Identifiers
    urn:nbn:se:uu:diva-360987 (URN)
    Available from: 2018-09-20 Created: 2018-09-20 Last updated: 2018-10-30
  • 19.
    Ahnfelt, Emelie
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Al-Tikriti, Yassir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Sjögren, Erik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Lennernäs, Hans
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Hansson, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Single bead investigation of a clinical drug delivery system – a novel release mechanism2018In: Journal of Controlled Release, ISSN 0168-3659, E-ISSN 1873-4995, Vol. 292, p. 235-247Article in journal (Refereed)
    Abstract [en]

    Microgels, such as polymeric hydrogels, are currently used as drug delivery devices (DDSs) for chemotherapeutics and/or unstable drugs. The clinical DDS DC bead® was studied with respect to loading and release, measured as relative bead-volume, of six amphiphilic molecules in a micropipette-assisted microscopy method. Theoretical models for loading and release was used to increase the mechanistic understanding of the DDS.

    It was shown that equilibrium loading was independent of amphiphile concentration. The loading model showed that the rate-determining step was diffusion of the molecule from the bulk to the bead surface (‘film control’). Calculations with the developed and applied release model on the release kinetics were consistent with the observations, as the amphiphiles distribute unevenly in the bead. The rate determining step of the release was the diffusion of the amphiphile molecule through the developed amphiphile-free depletion layer. The release rate is determined by the diffusivity and the tendency for aggregation of the amphiphile where a weak tendency for aggregation (i.e. a large cacb) lead to faster release. Salt was necessary for the release to happen, but at physiological concentrations the entry of salt was not rate-determining. This study provides valuable insights into the loading to and release from the DDS. Also, a novel release mechanism of the clinically used DDS is suggested.

  • 20.
    Ahnfelt, Emelie
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Degerstedt, Oliver
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Lilienberg, Elsa
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Sjögren, Erik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Hansson, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Lennernäs, Hans
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    In vitro evaluation of lipiodol-based emulsions in clinical useManuscript (preprint) (Other academic)
  • 21.
    Ahnfelt, Emelie
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Degerstedt, Oliver
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Lilienberg, Elsa
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Sjögren, Erik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Hansson, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Lennernäs, Hans
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Lipiodol-based emulsions used for transarterial chemoembolization and drug delivery: Effects of composition on stability and product quality2019In: Journal of Drug Delivery Science and Technology, ISSN 1773-2247, Vol. 53, article id UNSP 101143Article in journal (Refereed)
    Abstract [en]

    Transarterial chemoembolization with emulsion-based formulations using doxorubicin hydrochloride (DOX) and Lipiodol (R) is the golden standard for the loco-regional treatment of unresectable hepatocellular carcinoma (HCC). However, from a pharmaceutical quality perspective these emulsions are poorly characterized. In this study, clinically relevant Lipiodol (R)-based emulsions were characterized in terms of emulsion stability, continuous phase classification and droplet-size distribution. Also, the solubility of DOX in the different emulsion components and the distribution of DOX to the lipid phase were investigated. These are key features to investigate due to the claimed tumor-seeking properties of Lipiodol (R). The in vitro release of DOX was studied in a miniaturized dialysis method and an empirical release model was applied to adjust for the passage of DOX across the dialysis membrane. The most stable emulsion ( > 72 h) was classified as water-in-oil (w/o), had the highest distribution of DOX to the lipid phase (20%) and an aqueous-to-lipid phase ratio of 1:4. The composition of the aqueous phase was a mixture (v/v) of iohexol (85%) and water (15%). Emulsions containing iohexol and a high aqueousto-lipid phase ratio (1:2-1:4) displayed prolonged in vitro release profiles of DOX. This study further emphasizes the medical need to standardize these emulsion-based drug delivery systems.

  • 22.
    Ahnfelt, Emelie
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Sjögren, Erik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Axén, N.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Lennernäs, Hans
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    A miniaturized in vitro release method for investigating drug-release mechanisms2015In: International Journal of Pharmaceutics, ISSN 0378-5173, E-ISSN 1873-3476, Vol. 486, no 1-2, p. 339-349Article in journal (Refereed)
    Abstract [en]

    We have evaluated a miniaturized in vitro method, based on the mDISS Profiler (TM) technique that enables on-line monitoring of drug release from a 21 mu l sample with 10 ml of release medium. Four model drugs in eight clinically used formulations, including both solid and non-solid drug delivery systems, were investigated. The acquired data were compared with historical in vitro release data from the same formulations. Use of the Weibull function to describe the in vitro drug-release profiles allowed discrimination between the selected formulations with respect to the drug-release mechanisms. Comparison of the release data from the same formulation in different in vitro set-ups showed that the methodology used can affect the mechanism of in vitro release. We also evaluated the ability of the in vitro methods to predict in vivo activity by comparing simulated plasma concentration-time profiles acquired from the application of the biopharmaceutical software GI-Sim to the in vitro observations. In summary, the simulations based on the miniaturized-method release data predicted the plasma profiles as well as or more accurately than simulations based on the historical release data in 71% of the cases and this miniaturized in vitro method appears to be applicable for both solid and non-solid formulations.

  • 23.
    Ahnfelt, Emelie
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Sjögren, Erik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Hansson, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Lennernäs, Hans
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    In Vitro Release Mechanisms of Doxorubicin From a Clinical Bead Drug-Delivery System2016In: Journal of Pharmaceutical Sciences, ISSN 0022-3549, E-ISSN 1520-6017, Vol. 105, no 11, p. 3387-3398Article in journal (Refereed)
    Abstract [en]

    The release rate of doxorubicin (DOX) from the drug-delivery system (DDS), DC Bead, was studied by 2 miniaturized in vitro methods: free-flowing and sample reservoir. The dependencies of the release mechanisms on in vitro system conditions were investigated experimentally and by theoretical modeling. An inverse relationship was found between release rates and bead size, most likely due to the greater total surface area. The release rates correlated positively with temperature, release medium volume, and buffer strength, although the release medium volume had larger effect than the buffer strength. The sample reservoir method generated slower release rates, which described the in vivo release profile more accurately than the free-flowing method. There was no difference between a pH of 6.3 or 7.4 on the release rate, implying that the slightly acidic tumor microenvironment is less importance for drug release. A positive correlation between stirring rate and release rate for all DDS sizes was observed, which suggests film controlled release. Theoretical modeling highlighted the influence of local equilibrium of protonation, self-aggregation, and bead material interactions of DOX. The theoretical release model might describe the observed larger sensitivity of the release rate to the volume of the release medium compared to buffer strength. A combination of miniaturized in vitro methods and theoretical modeling are useful to identify the important parameters and processes for DOX release from a micro gel-based DDS.

  • 24.
    Al-Amin, Rasel A.
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology. Science for Life Laboratory, SciLifeLab, Science for Life Laboratory, SciLifeLab.
    Johansson, Lars
    Division of Translational Medicine & Chemical Biology, Department of Medical Biochemistry & Biophysics, Karolinska Institutet.
    Landegren, Nils
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Autoimmunity. Uppsala University, Science for Life Laboratory, SciLifeLab. Department of Medicine (Solna), Karolinska University Hospital, Karolinska Institutet.
    Löf, Liza
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Molecular tools. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Abdurakhmanov, Eldar
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Biochemistry.
    Blokzijl, Andries
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Molecular tools. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Svensson, Richard
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Lönn, Peter
    Uppsala University, Science for Life Laboratory, SciLifeLab. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Molecular tools. Dept. Of Immunology, Genetics and Pathology,.
    Söderberg, Ola
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Molecular tools. Uppsala University, Science for Life Laboratory, SciLifeLab. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Kamali-Moghaddam, Masood
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Molecular tools. Uppsala University, Science for Life Laboratory, SciLifeLab. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Danielson, U. Helena
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Biochemistry. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Artursson, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Lundbäck, Thomas
    Division of Translational Medicine & Chemical Biology, Department of Medical Biochemistry & Biophysics, Karolinska Institutet.
    Landegren, Ulf
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Molecular tools. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Target Engagement-Mediated Amplification for Monitoring Drug-Target Interactions in SituManuscript (preprint) (Other academic)
    Abstract [en]

    It is important to determine the localization of drugs or drug candidates at cellular and subcellular resolution in relevant clinical specimens. This is necessary to evaluate drug candidates from early stages of drug development to clinical evaluation of mutations potentially causing resistance to targeted therapy. We describe a technology where oligonucleotide-conjugated drug molecules are used to visualize and measure target engagement in situ via rolling-circle amplification (RCA) of circularized oligonucleotide probes (padlock probes). We established this target engagement-mediated amplification (TEMA) technique using kinase inhibitor precursor compounds, and we applied the assay to investigate target interactions by microscopy in pathology tissue sections and using flow cytometry for blood samples from patients, as well as in commercial arrays including almost half of all human proteins.  In the variant proxTEMAtechnique, in situ proximity ligation assays were performed by combining drug-DNA conjugates with antibody-DNA conjugates to specifically reveal drug binding to particular on- or off-targets in pathological tissues sections. In conclusion, the TEMA methods successfully visualize drug-target interaction by experimental and clinically approved kinase inhibitors in situ and with kinases among a large collection of arrayed proteins. 

  • 25. Albertsson, AC
    et al.
    Carlfors, J
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy.
    Sturesson, C
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy.
    Preparation and characterisation of poly(adipic anhydride) microspheres for ocular drug delivery1996In: JOURNAL OF APPLIED POLYMER SCIENCE, Vol. 62, p. 695-Article in journal (Refereed)
  • 26.
    Alden, Maggie
    et al.
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy.
    Hillgren, Anna
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy.
    Investigation of aqueous solutions by modulated temperature differential scanning calorimetry1998In: THERMOCHIMICA ACTA, Vol. 311, p. 51-Article in journal (Refereed)
  • 27.
    Alderborn, A
    et al.
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy.
    Siegbahn, A
    Faculty of Medicine, Department of Medical Sciences.
    Wadelius, C
    Department of Genetics and Pathology.
    Venous thrombosis: factor V G1691A genotyping related to APC resistance as measured by 2 methods1997In: Eur J Haematol, Vol. 58, p. 229-Article in journal (Refereed)
  • 28.
    Alderborn, G
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy.
    A novel approach to derive a compression parameter indicating effective particle deformability.2003In: Pharm Dev Technol, Vol. 8, p. 367-Article in journal (Refereed)
  • 29.
    Alderborn, G
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy.
    Tablets and compaction2001In: Pharmaceutics - The science of dosage form design, Churchill Livingstone, London , 2001, Vol. 2Chapter in book (Other scientific)
  • 30.
    Alderborn, G
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy.
    Tablets and compaction2007In: Aulton´s Pharmaceutics - The design and manufacture of medicines. 3rd ed., Churchill Livingstone, Edinburgh , 2007Chapter in book (Refereed)
  • 31.
    Alderborn, G
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy.
    The effect of particle size and shape on the compactibility of powders1996In: Pharmaceutical Powder Compaction Technology, Marcel Dekker Inc., New York , 1996Chapter in book (Other scientific)
  • 32.
    Alderborn, Göran
    et al.
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy.
    Bjork, Erik
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy.
    Castensson, Staffan
    Johansson, Mats
    Waltersson, Jan-Olof
    Utformning av läkemedel2000Book (Other scientific)
  • 33.
    Alderborn, Göran
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Frenning, Göran
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Mechanical strength of tablets2008In: Pharmaceutical Dosage Forms: Tablets, Volume 3: Manufacture and Process Control, New York: Informa Healthcare , 2008, 3Chapter in book (Other academic)
  • 34.
    Alderborn, Göran
    et al.
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy.
    Nystrom, Christer
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy.
    Pharmaceutical Powder Compaction Technology1996Book (Other scientific)
  • 35.
    Alderborn, Göran
    et al.
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy.
    Wikberg, Martin
    Material properties of importance for powder volume reduction and compact strength1996In: Pharmaceutical Powder Compaction Technology, Marcel Dekker, Inc. , 1996Chapter in book (Other scientific)
  • 36.
    Alhalaweh, Amjad
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Alzghoul, Ahmad
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computing Science.
    Bergström, Christel A. S.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Molecular Drivers of Crystallization Kinetics for Drugs in Supersaturated Aqueous Solutions2019In: Journal of Pharmaceutical Sciences, ISSN 0022-3549, E-ISSN 1520-6017, Vol. 108, no 1, p. 252-259Article in journal (Refereed)
    Abstract [en]

    In this study, we explore molecular properties of importance in solution-mediated crystallization occurring in supersaturated aqueous drug solutions. Furthermore, we contrast the identified molecular properties with those of importance for crystallization occurring in the solid state. A literature data set of 54 structurally diverse compounds, for which crystallization kinetics from supersaturated aqueous solutions and in melt-quenched solids were reported, was used to identify molecular drivers for crystallization kinetics observed in solution and contrast these to those observed for solids. The compounds were divided into fast, moderate, and slow crystallizers, and in silico classification was developed using a molecular K-nearest neighbor model. The topological equivalent of Grav3 (related to molecular size and shape) was identified as the most important molecular descriptor for solution crystallization kinetics; the larger this descriptor, the slower the crystallization. Two electrotopological descriptors (the atom-type E-state index for -Caa groups and the sum of absolute values of pi Fukui(+) indices on C) were found to separate the moderate and slow crystallizers in the solution. The larger these descriptors, the slower the crystallization. With these 3 descriptors, the computational model correctly sorted the crystallization tendencies from solutions with an overall classification accuracy of 77% (test set).

  • 37.
    Alhalaweh, Amjad
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Alzghoul, Ahmad
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computing Science.
    Kaialy, Waseem
    Mahlin, Denny
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Bergström, Christel A. S.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Computational predictions of glass-forming ability and crystallization tendency of drug molecules2014In: Molecular Pharmaceutics, ISSN 1543-8384, E-ISSN 1543-8392, Vol. 11, no 9, p. 3123-3132Article in journal (Refereed)
    Abstract [en]

    Amorphization is an attractive formulation technique for drugs suffering from poor aqueous solubility as a result of their high lattice energy. Computational models that can predict the material properties associated with amorphization, such as glass-forming ability (GFA) and crystallization behavior in the dry state, would be a time-saving, cost-effective, and material-sparing approach compared to traditional experimental procedures. This article presents predictive models of these properties developed using support vector machine (SVM) algorithm. The GFA and crystallization tendency were investigated by melt-quenching 131 drug molecules in situ using differential scanning calorimetry. The SVM algorithm was used to develop computational models based on calculated molecular descriptors. The analyses confirmed the previously suggested cutoff molecular weight (MW) of 300 for glass-formers, and also clarified the extent to which MW can be used to predict the GFA of compounds with MW < 300. The topological equivalent of Grav3_3D, which is related to molecular size and shape, was a better descriptor than MW for GFA; it was able to accurately predict 86% of the data set regardless of MW. The potential for crystallization was predicted using molecular descriptors reflecting Hückel pi atomic charges and the number of hydrogen bond acceptors. The models developed could be used in the early drug development stage to indicate whether amorphization would be a suitable formulation strategy for improving the dissolution and/or apparent solubility of poorly soluble compounds.

  • 38.
    Alhalaweh, Amjad
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Alzghoul, Ahmad
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computing Science.
    Mahlin, Denny
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Bergström, Christel A. S.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Physical stability of drugs after storage above and below the glass transition temperature: Relationship to glass-forming ability2015In: International Journal of Pharmaceutics, ISSN 0378-5173, E-ISSN 1873-3476, Vol. 495, no 1, p. 312-317Article in journal (Refereed)
    Abstract [en]

    Amorphous materials are inherently unstable and tend to crystallize upon storage. In this study, we investigated the extent to which the physical stability and inherent crystallization tendency of drugs are related to their glass-forming ability (GFA), the glass transition temperature (T-g) and thermodynamic factors. Differential scanning calorimetry was used to produce the amorphous state of 52 drugs [ 18 compounds crystallized upon heating (Class II) and 34 remained in the amorphous state (Class III)] and to perform in situ storage for the amorphous material for 12 h at temperatures 20 degrees C above or below the T-g. A computational model based on the support vector machine (SVM) algorithm was developed to predict the structure-property relationships. All drugs maintained their Class when stored at 20 degrees C below the T-g. Fourteen of the Class II compounds crystallized when stored above the T-g whereas all except one of the Class III compounds remained amorphous. These results were only related to the glass-forming ability and no relationship to e. g. thermodynamic factors was found. The experimental data were used for computational modeling and a classification model was developed that correctly predicted the physical stability above the T-g. The use of a large dataset revealed that molecular features related to aromaticity and pi-pi interactions reduce the inherent physical stability of amorphous drugs.