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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. 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.

  • 4. 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)
  • 5.
    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.

  • 6.
    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)
  • 7.
    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)
  • 8.
    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)
  • 9.
    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)
  • 10.
    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.

  • 11.
    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)
  • 12.
    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
    Show others...
    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
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    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
  • 13.
    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.

  • 14.
    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.

  • 15.
    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.

  • 16. 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)
  • 17.
    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 mechanismManuscript (preprint) (Other academic)
  • 18.
    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)
  • 19.
    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.

  • 20.
    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.

  • 21. 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)
  • 22.
    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)
  • 23.
    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)
  • 24.
    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)
  • 25.
    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)
  • 26.
    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)
  • 27.
    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)
  • 28.
    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)
  • 29.
    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)
  • 30.
    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)
  • 31.
    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)
  • 32.
    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.

  • 33.
    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.

  • 34.
    Alhalaweh, Amjad
    et al.
    Purdue Univ, Dept Ind & Phys Pharm, Coll Pharm, 575 Stadium Mall Dr, W Lafayette, IN 47907 USA.
    Bergström, Christel A. S.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Taylor, Lynne S.
    Purdue Univ, Dept Ind & Phys Pharm, Coll Pharm, 575 Stadium Mall Dr, W Lafayette, IN 47907 USA.
    Compromised in vitro dissolution and membrane transport of multidrug amorphous formulations.2016In: Journal of Controlled Release, ISSN 0168-3659, E-ISSN 1873-4995, Vol. 229, p. 172-182Article in journal (Refereed)
    Abstract [en]

    Herein, the thermodynamic properties of solutions evolving from the non-sink dissolution of amorphous solid dispersions (ASDs) containing two or more drugs have been evaluated, focusing on the maximum achievable supersaturation and tendency of the system to undergo liquid-liquid phase separation (LLPS). Ritonavir (RTV) and atazanavir (ATV) were co-formulated with polyvinylpyrrolidone to produce ASDs with different molar ratios of each drug, and the dissolution profile of each drug was studied under non-sink conditions. The phase behavior of the supersaturated solutions generated by ASD dissolution was compared to that of supersaturated solutions generated by antisolvent addition. Dissolution of an ASD containing RTV, ATV and lopinavir (LPV) was also investigated. A thermodynamic model was used to predict the maximum achievable supersaturation for ASDs containing two and three drugs. In addition, a transport study with Caco-2 cells was conducted to evaluate the impact of co-addition of drugs on membrane transport. It was found that the formulation containing a 1:1 molar ratio of RTV and ATV achieved only 50% of the supersaturation attained by dissolution of the single drug systems. The maximum achievable concentration of ATV decreased linearly as the mole fraction of ATV in the formulation decreased and a similar trend was observed for RTV. For the dispersion containing a 1:1:1 molar ratio of RTV, ATV and LPV, the maximum concentration of each drug was only one third of that achieved for the single drug formulations. The decrease in the achievable supersaturation was well-predicted by the thermodynamic model for both the binary and ternary drug combinations. These observations can be explained by a decrease in the concentration at which the drugs undergo LLPS in the presence of other miscible drugs, thereby reducing the maximum achievable supersaturation of each drug. The reduced free drug concentration was reflected by a decreased flux across Caco-2 cells for the drug combinations compared to drug alone. This study sheds light on the complex dissolution and solution phase behavior of multicomponent amorphous dosage forms, in particular those containing poorly water soluble drugs, which may undergo supersaturation in vivo.

  • 35. Alison, Lauriane
    et al.
    Demirörs, Ahmet F
    Tervoort, Elena
    Teleki, Alexandra
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy. Nutritional R&D Center Formulation and Application, DSM Nutritional Products Ltd., P.O. Box 2676, 4002 Basel, Switzerland.
    Vermant, Jan
    Studart, Andre R
    Emulsions Stabilized by Chitosan-Modified Silica Nanoparticles: pH Control of Structure-Property Relations2018In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 34, no 21, p. 6147-6160Article in journal (Refereed)
    Abstract [en]

    In food-grade emulsions, particles with an appropriate surface modification can be used to replace surfactants and potentially enhance the stability of emulsions. During the life cycle of products based on such emulsions, they can be exposed to a broad range of pH conditions and hence it is crucial to understand how pH changes affect stability of emulsions stabilized by particles. Here, we report on a comprehensive study of the stability, microstructure, and macroscopic behavior of pH-controlled oil-in-water emulsions containing silica nanoparticles modified with chitosan, a food-grade polycation. We found that the modified colloidal particles used as stabilizers behave differently depending on the pH, resulting in unique emulsion structures at multiple length scales. Our findings are rationalized in terms of the different emulsion stabilization mechanisms involved, which are determined by the pH-dependent charges and interactions between the colloidal building blocks of the system. At pH 4, the silica particles are partially hydrophobized through chitosan modification, favoring their adsorption at the oil-water interface and the formation of Pickering emulsions. At pH 5.5, the particles become attractive and the emulsion is stabilized by a network of agglomerated particles formed between the droplets. Finally, chitosan aggregates form at pH 9 and these act as the emulsion stabilizers under alkaline conditions. These insights have important implications for the processing and use of particle-stabilized emulsions. On one hand, changes in pH can lead to undesired macroscopic phase separation or coalescence of oil droplets. On the other hand, the pH effect on emulsion behavior can be harnessed in industrial processing, either to tune their flow response by altering the pH between processing stages or to produce pH-responsive emulsions that enhance the functionality of the emulsified end products.

  • 36.
    Almgren, Mats
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical Chemistry.
    Hansson, Per
    Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy.
    Fluorescence studies of micelles2002Chapter in book (Refereed)
  • 37.
    Almqvist, Helena
    et al.
    Laboratories for Chemical Biology Karolinska Institutet Science for Life Laboratory Stockholm, Division of Translational Medicine & Chemical Biology.
    Axelsson, Hanna
    Laboratories for Chemical Biology Karolinska Institutet Science for Life Laboratory Stockholm, Division of Translational Medicine & Chemical Biology.
    Jafari, Rozbeh
    Department of Medical Biochemistry & Biophysics, Division of Biophysics, Karolinska Institutet.
    Dan, Chen
    School of Biological Sciences, Nanyang Technological University.
    Mateus, André
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Haraldsson, Martin
    Laboratories for Chemical Biology Karolinska Institutet Science for Life Laboratory Stockholm, Division of Translational Medicine & Chemical Biology.
    Larsson, Andreas
    School of Biological Sciences, Nanyang Technological University.
    Martinez-Molina, Daniel
    Department of Medical Biochemistry & Biophysics, Division of Biophysics, Karolinska Institutet.
    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
    Laboratories for Chemical Biology Karolinska Institutet Science for Life Laboratory Stockholm, Division of Translational Medicine & Chemical Biology.
    Nordlund, Pär
    Department of Medical Biochemistry & Biophysics, Division of Biophysics, Karolinska Institutet.
    CETSA screening identifies known and novel thymidylate synthase inhibitors and slow intracellular activation of 5-fluorouracil2016In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 7, article id 11040Article in journal (Refereed)
    Abstract [en]

    Target engagement is a critical factor for therapeutic efficacy. Assessment of compound binding to native target proteins in live cells is therefore highly desirable in all stages of drug discovery. We report here the first compound library screen based on biophysical measurements of intracellular target binding, exemplified by human thymidylate synthase (TS). The screen selected accurately for all the tested known drugs acting on TS. We also identified TS inhibitors with novel chemistry and marketed drugs that were not previously known to target TS, including the DNA methyltransferase inhibitor decitabine. By following the cellular uptake and enzymatic conversion of known drugs we correlated the appearance of active metabolites over time with intracellular target engagement. These data distinguished a much slower activation of 5-fluorouracil when compared with nucleoside-based drugs. The approach establishes efficient means to associate drug uptake and activation with target binding during drug discovery.

  • 38.
    Alskär, Linda C
    et al.
    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.
    Models for Predicting Drug Absorption From Oral Lipid-Based Formulations2015In: Current molecular biology reports, ISSN 2198-6428, Vol. 1, no 4, p. 141-147Article in journal (Refereed)
    Abstract [en]

    In this review, we describe the in vitro tools currently used to identify when a lipid-based formulation has the potential to deliver a poorly water-soluble drug via the oral route. We describe the extent to which these tools reflect the in vivo performance of the formulation and, more importantly, we present strategies that we foresee will improve the in vitro-in vivo correlations. We also present emerging computational methods that are likely to allow large parts of the formulation development to be carried out in the computer rather than in the test tube. We suggest that these computational tools will also improve the mechanistic understanding of in vivo formulation performance in the complex and dynamic environment of the gut.

  • 39.
    Alskär, Linda C.
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Porter, Christopher J. H.
    Monash Univ, Monash Inst Pharmaceut Sci, Drug Delivery Disposit & Dynam, Parkville, Vic 3052, Australia..
    Bergström, Christel A. S.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy. UMonash Univ, Monash Inst Pharmaceut Sci, Drug Delivery Disposit & Dynam, Parkville, Vic 3052, Australia..
    Tools for Early Prediction of Drug Loading in Lipid-Based Formulations2016In: Molecular Pharmaceutics, ISSN 1543-8384, E-ISSN 1543-8392, Vol. 13, no 1, p. 251-261Article in journal (Refereed)
    Abstract [en]

    Identification of the usefulness of lipid-based formulations (LBFs) for delivery of poorly water-soluble drugs is at date mainly experimentally based. In this work we used a diverse drug data set, and more than 2,000 solubility measurements to develop experimental and computational tools to predict the loading capacity of LBFs. Computational models were developed to enable in silico prediction of solubility, and hence drug loading capacity, in the LBFs. Drug solubility in mixed mono-, di-, triglycerides (Maisine 35-1 and Capmul MCM EP) correlated (R-2 0.89) as well as the drug solubility in Carbitol and other ethoxylated excipients (PEG400, R-2 0.85; Polysorbate 80, R-2 0.90; Cremophor EL, R-2 0.93). A melting point below 150 degrees C was observed to result in a reasonable solubility in the glycerides. The loading capacity in LBFs was accurately calculated from solubility data in single excipients (R-2 0.91). In silico models, without the demand of experimentally determined solubility, also gave good predictions of the loading capacity in these complex formulations (R-2 0.79). The framework established here gives a better understanding of drug solubility in single excipients and of LBF loading capacity. The large data set studied revealed that experimental screening efforts can be rationalized by solubility measurements in key excipients or from solid state information. For the first time it was shown that loading capacity in complex formulations can be accurately predicted using molecular information extracted from calculated descriptors and thermal properties of the crystalline drug.

  • 40.
    Alvebratt, Caroline
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Cheung, Ocean
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Strömme, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Bergström, Christel A S
    A Modified In Situ Method to Determine Release from a Complex Drug Carrier in Particle-Rich Suspensions.2018In: AAPS PharmSciTech, ISSN 1530-9932, E-ISSN 1530-9932Article in journal (Refereed)
    Abstract [en]

    Effective and compound-sparing methods to evaluate promising drug delivery systems are a prerequisite for successful selection of formulations in early development stages. The aim of the study was to develop a small-scale in situ method to determine drug release and supersaturation in highly concentrated suspensions of enabling formulations. Mesoporous magnesium carbonate (MMC), which delivers the drug in an amorphous form, was selected as a drug carrier. Five model compounds were loaded into the MMC at a 1:10 ratio using a solvent evaporation technique. The μDiss Profiler was used to study the drug release from MMC in fasted-state simulated intestinal fluid. To avoid extensive light scattering previously seen in particle-rich suspensions in the μDiss Profiler, an in-house-designed protective nylon filter was placed on the in situ UV probes. Three types of release experiments were conducted for each compound: micronized crystalline drug with MMC present, drug-loaded MMC, and drug-loaded MMC with 0.01% w/w hydroxypropyl methyl cellulose. The nylon filters effectively diminished interference with the UV absorption; however, the release profiles obtained were heavily compound dependent. For one of the compounds, changes in the UV spectra were detected during the release from the MMC, and these were consistent with degradation of the compound. To conclude, the addition of protective nylon filters to the probes of the μDiss Profiler is a useful contribution to the method, making evaluations of particle-rich suspensions feasible. The method is a valuable addition to the current ones, allowing for fast and effective evaluation of advanced drug delivery systems.

  • 41.
    Alvebratt, Caroline
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Petersson, E.
    Strömme, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Bergström, Christel
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    A small scale method to determine release rate from complexcarrier-mediated systems. 2016In: AAPS Annual Meeting and Exposition. Denver, November 13-17, 2016. / [ed] AAPS, 2016Conference paper (Refereed)
  • 42.
    Alvebratt, Caroline
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Petersson, E.
    Strömme, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Bergström, Christel
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Dissolution studies of solid formulations - Applicability of µDiss inmonitoring supersaturation, nucleation and crystallization behavior; Casestudy: Carrier-based formulation.2016In: pION Fiber Optic Advanced Training Course. Uppsala, June 14-15, 2016., 2016Conference paper (Refereed)
  • 43.
    Alvebratt, Caroline
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Petersson, Erik
    Strömme, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Bergström, Christel
    A small scale method to determine release rate from complex carrier-mediated systems2016In: Emerging Technologies in Drug Discovery and Development. Zhuhai, August 23-26, 2016., 2016Conference paper (Refereed)
  • 44.
    Alvebratt, Caroline
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Strömme, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Bergström, Christel
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    A new method that enables in situ measurement of drug release from complex carrier-mediated systems2017In: 6th FIP Pharmaceutical Sciences World Congress2017., 2017Conference paper (Refereed)
  • 45.
    Alzghoul, Ahmad
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computing Science.
    Alhalaweh, Amjad
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    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.
    Experimental and Computational Prediction of Glass Transition Temperature of Drugs2014In: JOURNAL OF CHEMICAL INFORMATION AND MODELING, ISSN 1549-9596, Vol. 54, no 12, p. 3396-3403Article in journal (Refereed)
    Abstract [en]

    Glass transition temperature (T-g) is an important inherent property of an amorphous solid material which is usually determined experimentally. In this study, the relation between T-g and melting temperature (T-m) was evaluated using a data set of 71 structurally diverse druglike compounds. Further, in silico models for prediction of T-g were developed based on calculated molecular descriptors and linear (multilinear regression, partial least-squares, principal component regression) and nonlinear (neural network, support vector regression) modeling techniques. The models based on T-m predicted T-g with an RMSE of 19.5 K for the test set. Among the five computational models developed herein the support vector regression gave the best result with RMSE of 18.7 K for the test set using only four chemical descriptors. Hence, two different models that predict T-g of drug-like molecules with high accuracy were developed. If T-m is available, a simple linear regression can be used to predict T-g. However, the results also suggest that support vector regression and calculated molecular descriptors can predict T-g with equal accuracy, already before compound synthesis.

  • 46. AMIDON, GL
    et al.
    LENNERNAS, H
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy.
    SHAH, VP
    CRISON, JR
    A THEORETICAL BASIS FOR A BIOPHARMACEUTIC DRUG CLASSIFICATION - THE CORRELATION OF IN-VITRO DRUG PRODUCT DISSOLUTION AND IN-VIVO BIOAVAILABILITY1995In: PHARMACEUTICAL RESEARCH, Vol. 12, p. 413-Article in journal (Refereed)
  • 47. Amidon, K. S.
    et al.
    Langguth, P.
    Lennernäs, Hans
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Yu, L.
    Amidon, G. L.
    Bioequivalence of Oral Products and the Biopharmaceutics Classification System: Science, Regulation, and Public Policy2011In: Clinical Pharmacology and Therapeutics, ISSN 0009-9236, E-ISSN 1532-6535, Vol. 90, no 3, p. 467-470Article in journal (Refereed)
    Abstract [en]

    The demonstration of bioequivalence (BE) is an essential requirement for ensuring that patients receive a product that performs as indicated by the label. The BE standard for a particular product is set by its innovator, and this standard must subsequently be matched by generic drug products. The Biopharmaceutics Classification System (BCS) sets a scientific basis for an improved BE standard for immediate-release solid oral dosage forms. In this paper, we discuss BE and the BCS, as well as the issues that are currently relevant to BE as a pharmaceutical product standard.

  • 48.
    Amini, A
    et al.
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Merclin, N
    Department of Pharmacy.
    Bastami, S
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Westerlund, D
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Determination of association constants between enantiomers of orciprenaline and methyl-beta-cyclodextrin as chiral selector by capillary zone electrophoresis using a partial filling technique1999In: ELECTROPHORESIS, Vol. 20, p. 180-Article in journal (Refereed)
  • 49. Amini, Ahmad
    et al.
    Merclin, Nadia
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmacy.
    Bastami, Salumeh
    Westerlund, Douglas
    Determination of association constants between enantiomers of orciprenaline and methyl-β-cyclodextrin as chiral selector by capillary zone electrophoresis using a partial filling technique1999In: Electrophoresis, Vol. 20, p. 180-188Article in journal (Refereed)
  • 50.
    Andersson, Emma
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Konkreta förbättringsförslag på farmaceutisk produktion för minimering av skadat innehåll av Salazopyrin EN-tabs 500mg2013Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
1234567 1 - 50 of 1600
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