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Barata IS, Rueff J, Kranendonk M, Esteves F. Pleiotropy of Progesterone Receptor Membrane Component 1 in Modulation of Cytochrome P450 Activity. J Xenobiot 2024; 14:575-603. [PMID: 38804287 PMCID: PMC11130977 DOI: 10.3390/jox14020034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 04/26/2024] [Accepted: 04/29/2024] [Indexed: 05/29/2024] Open
Abstract
Progesterone receptor membrane component 1 (PGRMC1) is one of few proteins that have been recently described as direct modulators of the activity of human cytochrome P450 enzymes (CYP)s. These enzymes form a superfamily of membrane-bound hemoproteins that metabolize a wide variety of physiological, dietary, environmental, and pharmacological compounds. Modulation of CYP activity impacts the detoxification of xenobiotics as well as endogenous pathways such as steroid and fatty acid metabolism, thus playing a central role in homeostasis. This review is focused on nine main topics that include the most relevant aspects of past and current PGRMC1 research, focusing on its role in CYP-mediated drug metabolism. Firstly, a general overview of the main aspects of xenobiotic metabolism is presented (I), followed by an overview of the role of the CYP enzymatic complex (IIa), a section on human disorders associated with defects in CYP enzyme complex activity (IIb), and a brief account of cytochrome b5 (cyt b5)'s effect on CYP activity (IIc). Subsequently, we present a background overview of the history of the molecular characterization of PGRMC1 (III), regarding its structure, expression, and intracellular location (IIIa), and its heme-binding capability and dimerization (IIIb). The next section reflects the different effects PGRMC1 may have on CYP activity (IV), presenting a description of studies on the direct effects on CYP activity (IVa), and a summary of pathways in which PGRMC1's involvement may indirectly affect CYP activity (IVb). The last section of the review is focused on the current challenges of research on the effect of PGRMC1 on CYP activity (V), presenting some future perspectives of research in the field (VI).
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Affiliation(s)
- Isabel S. Barata
- Department of Pediatrics, Division of Endocrinology, Diabetology and Metabolism, University Children’s Hospital, University of Bern, 3010 Bern, Switzerland;
- Translational Hormone Research Program, Department of Biomedical Research, University of Bern, 3010 Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, 3012 Bern, Switzerland
| | - José Rueff
- ToxOmics, NOVA Medical School, Faculdade de Ciências Médicas, NMS|FCM, Universidade NOVA de Lisboa, Campo Mártires da Pátria 130, 1169-056 Lisboa, Portugal;
| | - Michel Kranendonk
- ToxOmics, NOVA Medical School, Faculdade de Ciências Médicas, NMS|FCM, Universidade NOVA de Lisboa, Campo Mártires da Pátria 130, 1169-056 Lisboa, Portugal;
| | - Francisco Esteves
- ToxOmics, NOVA Medical School, Faculdade de Ciências Médicas, NMS|FCM, Universidade NOVA de Lisboa, Campo Mártires da Pátria 130, 1169-056 Lisboa, Portugal;
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Kapelemera AM, Uang YS, Wang LH, Wu TY, Lee FY, Tai L, Wang CC, Lee CJ. Pharmacokinetic Herb-Drug Interactions of Xiang-Sha-Liu-Jun-Zi-Tang and Paclitaxel in Male Sprague Dawley Rats and Its Influence on Enzyme Kinetics in Human Liver Microsomes. Front Pharmacol 2022; 13:858007. [PMID: 35450043 PMCID: PMC9016196 DOI: 10.3389/fphar.2022.858007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 02/28/2022] [Indexed: 11/13/2022] Open
Abstract
Paclitaxel is a prescribed anticancer drug used to treat various cancers. It is a substrate of cytochrome P-450 (CYP-450) enzymes. Despite its efficacy, paclitaxel has severe side effects. Herbal medicines are commonly used to treat the side effects of chemotherapy. They can be administered before, during, and after chemotherapy. Xiang-Sha-Liu-Jun-Zi Tang (XSLJZT) is a herbal formula commonly used in breast cancer patients. The main purpose of this study was to assess the pharmacokinetic (PK) influence of XSLJZT on paclitaxel PK parameters, determine its effect on CYP-450 enzyme expression, and evaluate its effect on enzyme activity. Sprague Dawley rats were classified into pretreatment and co-treatment groups, where XSLJZT was pre-administered for 3, 5, and 7 days and co-administered 2 h before paclitaxel administration. The rat liver tissues and Hep-G2 cells were used to determine the effects of XSLJZT on CYP3A1/2 and CYP3A4 enzymes respectively. Western blot analysis was used to detect changes in the CYP3A1/2 and CYP3A4 enzymes expression. The influence of XSLJZT on enzyme activity was evaluated using human liver microsomes, and a liquid chromatography-tandem mass spectrometric system was developed to monitor paclitaxel levels in rat plasma. Results demonstrated that XSLJZT increased the area under the concentration versus time curve (AUC) for paclitaxel in pretreatment groups by 2-, 3-, and 4-fold after 3, 5, and 7 days, respectively. In contrast, no significant change in the AUC was observed in the co-treatment group. However, the half-life was prolonged in all groups from 17.11 min to a maximum of 37.56 min. XSLJZT inhibited CYP3A1/2 expression in the rat liver tissues and CYP3A4 enzymes in Hep-G2 cells in a time-dependent manner, with the highest inhibition observed after 7 days of pretreatment in rat liver tissues. In the enzyme kinetics study, XSLJZT inhibited enzyme activity in a competitive dose-dependent manner. In conclusion, there is a potential interaction between XSLJZT and paclitaxel at different co-treatment and pretreatment time points.
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Affiliation(s)
- Alinafe Magret Kapelemera
- PhD Program in Clinical Drug Development of Herbal Medicine, Taipei Medical University, Taipei, Taiwan
| | - Yow-Shieng Uang
- Graduate Institute of Pharmacognosy, Taipei Medical University, Taipei, Taiwan.,Rosetta Pharmamate Co., Ltd, New Taipei City, Taiwan
| | - Li-Hsuan Wang
- School of Pharmacy, Taipei Medical University, Taipei, Taiwan
| | - Tien-Yuan Wu
- Department of Pharmacology, School of Medicine, College of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Fang-Yu Lee
- Graduate Institute of Pharmacognosy, Taipei Medical University, Taipei, Taiwan
| | - Li Tai
- Rosetta Pharmamate Co., Ltd, New Taipei City, Taiwan
| | - Ching-Chiung Wang
- PhD Program in Clinical Drug Development of Herbal Medicine, Taipei Medical University, Taipei, Taiwan.,Graduate Institute of Pharmacognosy, Taipei Medical University, Taipei, Taiwan.,School of Pharmacy, Taipei Medical University, Taipei, Taiwan.,Traditional Herbal Medicine Research Center, Taipei Medical University Hospital, Taipei, Taiwan
| | - Chia-Jung Lee
- PhD Program in Clinical Drug Development of Herbal Medicine, Taipei Medical University, Taipei, Taiwan.,Graduate Institute of Pharmacognosy, Taipei Medical University, Taipei, Taiwan.,Traditional Herbal Medicine Research Center, Taipei Medical University Hospital, Taipei, Taiwan
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Kameyama T, Sodhi JK, Benet LZ. Does Addition of Protein to Hepatocyte or Microsomal In Vitro Incubations Provide a Useful Improvement in In Vitro-In Vivo Extrapolation Predictability? Drug Metab Dispos 2022; 50:401-412. [PMID: 35086847 PMCID: PMC11022888 DOI: 10.1124/dmd.121.000677] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 01/21/2022] [Indexed: 11/22/2022] Open
Abstract
Accurate prediction of in vivo hepatic clearance is an essential part of successful and efficient drug development; however, many investigators have recognized that there are significant limitations in the predictability of clearance with a tendency for underprediction for primarily metabolized drugs. Here, we examine the impact of adding serum or albumin into hepatocyte and microsomal incubations on the predictability of in vivo hepatic clearance. The addition of protein into hepatocyte incubations has been reported to improve the predictability for high clearance (extraction ratio) drugs and highly protein-bound drugs. Analyzing published data for 60 different drugs and 97 experimental comparisons (with 17 drugs being investigated from two to seven) we confirmed the marked underprediction of clearance. However, we could not validate any relevant improved predictability within twofold by the addition of serum to hepatocyte incubations or albumin to microsomal incubations. This was the case when investigating all measurements, or when subdividing analyses by extraction ratio, degree of protein binding, Biopharmaceutics Drug Disposition Classification System class, examining Extended Clearance Classification System class 1B drugs only, or drug charge. Manipulating characteristics of small data sets of like compounds and adding scaling factors can appear to yield good predictability, but the carryover of these methods to alternate drug classes and different laboratories is not evident. Improvement in predictability of poorly soluble compounds is greater than that for soluble compounds, but not to a meaningful extent. Overall, we cannot confirm that protein addition improves in vitro-in vivo extrapolation predictability to any clinically meaningful degree when considering all drugs and different subsets. SIGNIFICANCE STATEMENT: The addition of protein into microsomal or hepatocyte incubations has been widely proposed to improve hepatic clearance predictions. To date, studies examining this phenomenon have not included appropriate negative controls where predictability is achieved without protein addition and have been conducted with small data sets of similar compounds that don't apply to alternate drug classes. Here, an extensive analysis of published data for 60 drugs and 97 experimental comparisons couldn't validate any relevant clinically improved clearance predictability with protein addition.
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Affiliation(s)
- Tsubasa Kameyama
- Department of Bioengineering and Therapeutic Sciences, Schools of Pharmacy and Medicine, University of California San Francisco, San Francisco, California
| | - Jasleen K Sodhi
- Department of Bioengineering and Therapeutic Sciences, Schools of Pharmacy and Medicine, University of California San Francisco, San Francisco, California
| | - Leslie Z Benet
- Department of Bioengineering and Therapeutic Sciences, Schools of Pharmacy and Medicine, University of California San Francisco, San Francisco, California
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Combining Therapeutic Drug Monitoring and Pharmacokinetic Modelling Deconvolutes Physiological and Environmental Sources of Variability in Clozapine Exposure. Pharmaceutics 2021; 14:pharmaceutics14010047. [PMID: 35056943 PMCID: PMC8779032 DOI: 10.3390/pharmaceutics14010047] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 12/13/2021] [Accepted: 12/22/2021] [Indexed: 11/17/2022] Open
Abstract
Background: Clozapine is a key antipsychotic drug for treatment-resistant schizophrenia but exhibits highly variable pharmacokinetics and a propensity for serious adverse effects. Currently, these challenges are addressed using therapeutic drug monitoring (TDM). This study primarily sought to (i) verify the importance of covariates identified in a prior clozapine population pharmacokinetic (popPK) model in the absence of environmental covariates using physiologically based pharmacokinetic (PBPK) modelling, and then to (ii) evaluate the performance of the popPK model as an adjunct or alternative to TDM-guided dosing in an active TDM population. Methods: A popPK model incorporating age, metabolic activity, sex, smoking status and weight was applied to predict clozapine trough concentrations (Cmin) in a PBPK-simulated population and an active TDM population comprising 142 patients dosed to steady state at Flinders Medical Centre in Adelaide, South Australia. Post hoc analyses were performed to deconvolute the impact of physiological and environmental covariates in the TDM population. Results: Analysis of PBPK simulations confirmed age, cytochrome P450 1A2 activity, sex and weight as physiological covariates associated with variability in clozapine Cmin (R2 = 0.7698; p = 0.0002). Prediction of clozapine Cmin using a popPK model based on these covariates accounted for <5% of inter-individual variability in the TDM population. Post hoc analyses confirmed that environmental covariates accounted for a greater proportion of the variability in clozapine Cmin in the TDM population. Conclusions: Variability in clozapine exposure was primarily driven by environmental covariates in an active TDM population. Pharmacokinetic modelling can be used as an adjunct to TDM to deconvolute sources of variability in clozapine exposure.
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Abstract
Accurate estimation of in vivo clearance in human is pivotal to determine the dose and dosing regimen for drug development. In vitro-in vivo extrapolation (IVIVE) has been performed to predict drug clearance using empirical and physiological scalars. Multiple in vitro systems and mathematical modeling techniques have been employed to estimate in vivo clearance. The models for predicting clearance have significantly improved and have evolved to become more complex by integrating multiple processes such as drug metabolism and transport as well as passive diffusion. This chapter covers the use of conventional as well as recently developed methods to predict metabolic and transporter-mediated clearance along with the advantages and disadvantages of using these methods and the associated experimental considerations. The general approaches to improve IVIVE by use of appropriate scalars, incorporation of extrahepatic metabolism and transport and application of physiologically based pharmacokinetic (PBPK) models with proteomics data are also discussed. The chapter also provides an overview of the advantages of using such dynamic mechanistic models over static models for clearance predictions to improve IVIVE.
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Miners JO, Rowland A, Novak JJ, Lapham K, Goosen TC. Evidence-based strategies for the characterisation of human drug and chemical glucuronidation in vitro and UDP-glucuronosyltransferase reaction phenotyping. Pharmacol Ther 2020; 218:107689. [PMID: 32980440 DOI: 10.1016/j.pharmthera.2020.107689] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 09/17/2020] [Accepted: 09/18/2020] [Indexed: 12/26/2022]
Abstract
Enzymes of the UDP-glucuronosyltransferase (UGT) superfamily contribute to the elimination of drugs from almost all therapeutic classes. Awareness of the importance of glucuronidation as a drug clearance mechanism along with increased knowledge of the enzymology of drug and chemical metabolism has stimulated interest in the development and application of approaches for the characterisation of human drug glucuronidation in vitro, in particular reaction phenotyping (the fractional contribution of the individual UGT enzymes responsible for the glucuronidation of a given drug), assessment of metabolic stability, and UGT enzyme inhibition by drugs and other xenobiotics. In turn, this has permitted the implementation of in vitro - in vivo extrapolation approaches for the prediction of drug metabolic clearance, intestinal availability, and drug-drug interaction liability, all of which are of considerable importance in pre-clinical drug development. Indeed, regulatory agencies (FDA and EMA) require UGT reaction phenotyping for new chemical entities if glucuronidation accounts for ≥25% of total metabolism. In vitro studies are most commonly performed with recombinant UGT enzymes and human liver microsomes (HLM) as the enzyme sources. Despite the widespread use of in vitro approaches for the characterisation of drug and chemical glucuronidation by HLM and recombinant enzymes, evidence-based guidelines relating to experimental approaches are lacking. Here we present evidence-based strategies for the characterisation of drug and chemical glucuronidation in vitro, and for UGT reaction phenotyping. We anticipate that the strategies will inform practice, encourage development of standardised experimental procedures where feasible, and guide ongoing research in the field.
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Affiliation(s)
- John O Miners
- Department of Clinical Pharmacology and Flinders Centre for Innovation in Cancer, College of Medicine and Public Health, Flinders University, Adelaide, Australia.
| | - Andrew Rowland
- Department of Clinical Pharmacology and Flinders Centre for Innovation in Cancer, College of Medicine and Public Health, Flinders University, Adelaide, Australia
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Adiwidjaja J, Boddy AV, McLachlan AJ. Physiologically-Based Pharmacokinetic Predictions of the Effect of Curcumin on Metabolism of Imatinib and Bosutinib: In Vitro and In Vivo Disconnect. Pharm Res 2020; 37:128. [PMID: 32529309 DOI: 10.1007/s11095-020-02834-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Accepted: 04/26/2020] [Indexed: 12/14/2022]
Abstract
PURPOSE This study aimed to investigate the potential pharmacokinetic interactions between curcumin, imatinib and bosutinib, combining In Vitro and in silico methods. METHODS In Vitro metabolism of imatinib and bosutinib were investigated in pooled human liver microsomes and recombinant CYP3A4 enzyme in the presence and absence of curcumin and curcumin glucuronide using an LC-MS/MS assay for N-desmethyl metabolites. A physiologically-based pharmacokinetic (PBPK) model for curcumin formulated as solid lipid nanoparticles (SLN) was constructed using In Vitro glucuronidation kinetics and published clinical pharmacokinetic data. The potential effects of curcumin coadministration on systemic exposures of imatinib and bosutinib were predicted in silico using PBPK simulations. RESULTS Curcumin demonstrated potent reversible inhibition of cytochrome P450 (CYP)3A4-mediated N-demethylation of imatinib and bosutinib and CYP2C8-mediated metabolism of imatinib with inhibitory constants (ki,u) of ≤1.5 μmol. L-1. A confirmatory In Vitro study with paclitaxel, the 6α-hydroxylation of which is exclusively mediated by CYP2C8, was consistent with a potent inhibition of this enzyme by curcumin. Curcumin glucuronide also inhibited both CYP enzymes In Vitro, albeit to a lesser extent than that of curcumin. PBPK model simulations predicted that at recommended dosing regimens of SLN curcumin, coadministration would result in an increase in systemic exposures of imatinib and bosutinib of up to only 10%. CONCLUSION A PBPK model for curcumin in a SLN formulation was successfully developed. Although curcumin possesses a strong In Vitro inhibitory activity towards CYP3A4 and CYP2C8 enzymes, its interactions with imatinib and bosutinib were unlikely to be of clinical importance due to curcumin's poor bioavailability.
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Affiliation(s)
- Jeffry Adiwidjaja
- Sydney Pharmacy School, The University of Sydney, Sydney, NSW, 2006, Australia.
| | - Alan V Boddy
- School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, 5001, Australia
- University of South Australia Cancer Research Institute, University of South Australia, Adelaide, SA, 5000, Australia
| | - Andrew J McLachlan
- Sydney Pharmacy School, The University of Sydney, Sydney, NSW, 2006, Australia
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A physiologically based pharmacokinetic - pharmacodynamic modelling approach to predict incidence of neutropenia as a result of drug-drug interactions of paclitaxel in cancer patients. Eur J Pharm Sci 2020; 150:105355. [PMID: 32438273 DOI: 10.1016/j.ejps.2020.105355] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 02/21/2020] [Accepted: 04/17/2020] [Indexed: 12/24/2022]
Abstract
Paclitaxel is the backbone of standard chemotherapeutic regimens used in a number of malignancies and is frequently given with concomitant medications. Newly developed oncolytic agents, including tyrosine kinase inhibitors are often shown to be CYP3A4 and P-gp inhibitors. The aim of this study was to develop a PBPK model for intravenously administered paclitaxel in order to predict the incidence of neutropenia and to estimate the DDI potential as a victim drug. The dose-dependent effects on paclitaxel plasma protein binding, volume of distribution and drug clearance were considered for dose levels of 80 mg/m2, 135 mg/m2 and 175 mg/m2. A pharmacodynamics model that incorporate the impact of paclitaxel on the neutrophil was developed. The relative metabolic clearance via CYP3A4 and CYP2C8, the renal clearance as well as P-gp mediated biliary clearance were incorporated in the model in order to assess the neutropenia in the presence of DDI. The developed PBPK-PD model was able to recover the drop in neutrophils observed after the administration of 175mg/m2 of paclitaxel over a 3-h duration. The mean nadir observed was 1.9 × 109 neutrophils/L and was attained after 10 days of treatment, and a fraction of 47% of the population was predicted to have at some point a neutropenia including 12% with severe neutropenia. In the case of concomitant administration of ketoconazole, 39% of the population was predicted to suffer from severe neutropenia. In summary, PBPK-PD modeling allows a priori prediction of DDIs and safety events involving complex combination therapies which are often utilized in an oncology setting.
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Chang JH, Chen YC, Cheong J, Jones RS, Pang J. Investigating the Impact of Albumin on the Liver Uptake of Pitavastatin and Warfarin in Nagase Analbuminemic Rats. Drug Metab Dispos 2019; 47:1307-1313. [PMID: 31492695 DOI: 10.1124/dmd.119.088278] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 09/03/2019] [Indexed: 11/22/2022] Open
Abstract
Albumin has been suggested to enhance the hepatic uptake of organic anion-transporting polypeptide (Oatp) substrates in various in vitro as well as liver perfusion models. However, it is not known whether the interplay between albumin and Oatp substrates is an experimental artifact or if this interaction occurs in vivo. The objective of this work was to investigate the hepatic uptake of warfarin and pitavastatin, which are both extensively bound to albumin but only pitavastatin being an Oatp substrate. Experiments were conducted in Nagase analbuminemic rats (NAR) which exhibit reduced albumin levels compared with F344 (wild type, WT). The fraction unbound (f u) was 140- and 10-fold greater in NAR plasma for warfarin and pitavastatin, respectively, whereas no meaningful differences were observed with tissue binding. In vitro, pitavastatin uptake into hepatocytes reconstituted in WT plasma was 17- and 3-fold greater than when reconstituted in buffer or NAR plasma, respectively. In vivo, the free tissue-to-free plasma ratios (K p,u,u) from brain and liver in intact WT and NAR were not significantly different for warfarin. Contrarily, liver K p,u,u of pitavastatin was 6-fold higher in WT animals, which corresponded to a 2.3-fold reduction in free plasma and 2.6-fold increase in free liver exposure. These results suggest that the enhanced hepatic uptake by albumin is not necessarily an experimental artifact but is also a relevant phenomenon in vivo. This work raises the possibility that other plasma proteins may also effect the function of additional drug transporters, and that modulating plasma protein binding may exhibit meaningful clinical relevance in the disposition of drugs. SIGNIFICANCE STATEMENT: The interplay between albumin and Oatp substrates has been reported in hepatocytes and in liver perfusion studies, but the in vivo relevance of this interaction has yet to be elucidated. Using NAR and its corresponding WT animal, this study demonstrates that albumin may indeed enhance the hepatic uptake of pitavastatin in intact animals. In vivo demonstration of this interplay not only provides further justification for continued investigation into this particular mechanism but also raises the possibility that other plasma proteins may affect additional drug transporters and that modulating plasma protein binding may exhibit meaningful clinical relevance in the disposition of drugs.
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Affiliation(s)
- Jae H Chang
- Department of Drug Metabolism and Pharmacokinetics, Genentech Inc., South San Francisco, California
| | - Yi-Chen Chen
- Department of Drug Metabolism and Pharmacokinetics, Genentech Inc., South San Francisco, California
| | - Jonathan Cheong
- Department of Drug Metabolism and Pharmacokinetics, Genentech Inc., South San Francisco, California
| | - Robert S Jones
- Department of Drug Metabolism and Pharmacokinetics, Genentech Inc., South San Francisco, California
| | - Jodie Pang
- Department of Drug Metabolism and Pharmacokinetics, Genentech Inc., South San Francisco, California
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Pang KS, Han YR, Noh K, Lee PI, Rowland M. Hepatic clearance concepts and misconceptions: Why the well-stirred model is still used even though it is not physiologic reality? Biochem Pharmacol 2019; 169:113596. [PMID: 31398312 DOI: 10.1016/j.bcp.2019.07.025] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 07/30/2019] [Indexed: 12/22/2022]
Abstract
The liver is the most important drug metabolizing organ, endowed with a plethora of metabolizing enzymes and transporters to facilitate drug entry and removal via metabolism and/or biliary excretion. For this reason, much focus surrounds the development of clearance concepts, which are based on normalizing the rate of removal to the input or arterial concentration. By so doing, some authors have recently claimed that it implies one specific model of hepatic elimination, namely, the widely used well-stirred or venous equilibration model (WSM). This commentary challenges this claim and aims to provide a comprehensive discussion of not only the WSM but other currently applied hepatic clearance models - the parallel tube model (PTM), the dispersion model (DM), the zonal liver model (ZLM), and the heterogeneous capillary transit time model of Goresky and co-workers (GM). The WSM, PTM, and DM differ in the patterns of internal blood flow, assuming bulk, plug, and dispersive flows, respectively, which render different degrees of mixing within the liver that are characterized by the magnitudes of the dispersion number (DN), resulting in different implications concerning the (unbound) substrate concentration in liver (CuH). Early models assumed perfusion rate-limited distribution, which have since been modified to include membrane-limited transport. The recent developments associated with the misconceptions and the sensitivity of the models are hereby addressed. Since the WSM has been and will likely remain widely used, the pros and cons of this model relative to physiological reality are further discussed.
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Affiliation(s)
- K Sandy Pang
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada.
| | - Yi Rang Han
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Keumhan Noh
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Ping I Lee
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Malcolm Rowland
- Centre for Applied Pharmacokinetic Research, University of Manchester, United Kingdom
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Kapetas AJ, Sorich MJ, Rodrigues AD, Rowland A. Guidance for Rifampin and Midazolam Dosing Protocols To Study Intestinal and Hepatic Cytochrome P450 (CYP) 3A4 Induction and De-induction. AAPS JOURNAL 2019; 21:78. [DOI: 10.1208/s12248-019-0341-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Accepted: 05/15/2019] [Indexed: 12/24/2022]
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Abstract
In this review, 9 compounds with insufficient absorption characteristics, safety or efficacy were selected from among the compounds for which the author was in charge of development between 2000 and 2005, in order to evaluate the pharmacokinetic (PK) approaches used to develop these compounds. Optimization of the PK characteristics of a compound at the early stage of chemical design was found to be the most important factor for successful development. For example, (i) selecting class I or II drugs in the biopharmaceutical classification system, while avoiding efflux transporters, and introducing an appropriate dissociation moiety into a compound to make it soluble lead to sufficient drug absorption; (ii) designing compounds whose production of reactive metabolites, such as acyl glucuronide, does not largely affect total metabolism, yet helps to prevent abnormal PK caused by reactive metabolites. Other factors include (i) selection of a drug efficacy evaluation system based on the correct understanding of the relationship between PK and pharmacodynamics (PD) helps to solve species differences in PD; (ii) the establishment of a nonclinical study based on the identification of the involvement of specific cytochrome P450 molecules in the total metabolic clearance of a drug (fm,CYPs) helps to solve species differences in PK; and (iii) PK analysis using the tube model for hepatic extraction kinetics, and knowledge of the fm,CYPs of the victim drug, lead to successful drug-drug interaction (DDI) prediction. I hope that this review aids in future drug discovery or development.
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Affiliation(s)
- Katsumi Iga
- Department of Clinical Pharmacy, Faculty of Pharmaceutical Sciences, Doshisha Women's College of Liberal Arts
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Fujino R, Hashizume K, Aoyama S, Maeda K, Ito K, Toshimoto K, Lee W, Ninomiya SI, Sugiyama Y. Strategies to improve the prediction accuracy of hepatic intrinsic clearance of three antidiabetic drugs: Application of the extended clearance concept and consideration of the effect of albumin on CYP2C metabolism and OATP1B-mediated hepatic uptake. Eur J Pharm Sci 2018; 125:181-192. [DOI: 10.1016/j.ejps.2018.09.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 09/03/2018] [Accepted: 09/28/2018] [Indexed: 01/20/2023]
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Bowman CM, Benet LZ. An examination of protein binding and protein-facilitated uptake relating to in vitro-in vivo extrapolation. Eur J Pharm Sci 2018; 123:502-514. [PMID: 30098391 DOI: 10.1016/j.ejps.2018.08.008] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 08/03/2018] [Accepted: 08/04/2018] [Indexed: 01/09/2023]
Abstract
As explained by the free drug theory, the unbound fraction of drug has long been thought to drive the efficacy of a molecule. Thus, the fraction unbound term, or fu, appears in equations for fundamental pharmacokinetic parameters such as clearance, and is used when attempting in vitro to in vivo extrapolation (IVIVE). In recent years though, it has been noted that IVIVE does not always yield accurate predictions, and that some highly protein bound ligands have more efficient uptake than can be explained by their unbound fractions. This review explores the evolution of fu terms included when implementing IVIVE, the concept of protein-facilitated uptake, and the mechanisms that have been proposed to account for facilitated uptake.
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Affiliation(s)
- C M Bowman
- Department of Bioengineering and Therapeutic Sciences, Schools of Pharmacy and Medicine, University of California San Francisco, San Francisco, CA, USA
| | - L Z Benet
- Department of Bioengineering and Therapeutic Sciences, Schools of Pharmacy and Medicine, University of California San Francisco, San Francisco, CA, USA.
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Shimura K, Murayama N, Tanaka S, Onozeki S, Yamazaki H. Suitable albumin concentrations for enhanced drug oxidation activities mediated by human liver microsomal cytochrome P450 2C9 and other forms predicted with unbound fractions and partition/distribution coefficients of model substrates. Xenobiotica 2018; 49:557-562. [PMID: 29808734 DOI: 10.1080/00498254.2018.1482576] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Albumin has reportedly enhanced cytochrome P450 (P450)-mediated drug oxidation rates in human liver microsomes. Consequently, measurements of clearances and fractions metabolized could vary depending on the experimental albumin concentrations used. In this study, the oxidation rates of diclofenac and warfarin by human liver microsomes were significantly enhanced in the presence of 0.10% (w/v) bovine serum albumin, whereas those of tolbutamide and phenytoin required 1.0% and 2.0% of albumin for significant enhancement. Values of the fractions metabolized by P450 2C9 for four substrates did not markedly change in the presence of albumin at the above-mentioned concentrations. The oxidation rates of bupropion, omeprazole, chlorzoxazone and phenacetin in human liver microsomes were reportedly enhanced by 0.5%, 1%, 2% and 2% of albumin, respectively. Analysis of reported intrinsic clearance values and suitable albumin concentrations for the currently analyzed substrates and the reported substrates revealed an inverse correlation, with warfarin as an outlier. Suitable albumin concentrations were multivariately correlated with physicochemical properties, that is, the plasma unbound fractions, octanol-water partition coefficient and acid dissociation constant (r = 0.98, p<.0001, n = 10). Therefore, multiple physicochemical properties may be determinants of suitable albumin concentrations for substrate oxidations in human liver microsomes.
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Affiliation(s)
- Kanami Shimura
- a Laboratory of Drug Metabolism and Pharmacokinetics , Showa Pharmaceutical University , Machida , Tokyo , Japan
| | - Norie Murayama
- a Laboratory of Drug Metabolism and Pharmacokinetics , Showa Pharmaceutical University , Machida , Tokyo , Japan
| | - Saki Tanaka
- a Laboratory of Drug Metabolism and Pharmacokinetics , Showa Pharmaceutical University , Machida , Tokyo , Japan
| | - Shunsuke Onozeki
- a Laboratory of Drug Metabolism and Pharmacokinetics , Showa Pharmaceutical University , Machida , Tokyo , Japan
| | - Hiroshi Yamazaki
- a Laboratory of Drug Metabolism and Pharmacokinetics , Showa Pharmaceutical University , Machida , Tokyo , Japan
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16
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Atypical Kinetics and Albumin Effect of Glucuronidation of 5-n-Butyl-4-{4-[2-(1H-tetrazole-5- yl)-1H-pyrrol-1-yl]phenylmethyl}-2,4-dihydro-2-(2,6- dichlorophenyl)-3H-1,2,4-triazol-3-one, a Novel Nonpeptide Angiotensin Type 1 Receptor Antagonist, in Liver Microsomes and UDP-Glucuronosyl-transferase. Molecules 2018; 23:molecules23030688. [PMID: 29562678 PMCID: PMC6017351 DOI: 10.3390/molecules23030688] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 03/08/2018] [Accepted: 03/16/2018] [Indexed: 12/12/2022] Open
Abstract
Ib is a new nonpeptide AT1 receptor antagonist, which plays an active role in cardiovascular protection. Ib monoglucuronide has been identified as its main metabolite. A detailed study of Ib glucuronidation is important for predicting potential DDI. Besides, the elucidation of the “BSA effect” in Ib glucuronidation would make obtained kinetic parameters more predictive in IVIVE. “BSA effect” means that there is a significant change in in vitro kinetic parameters when generated from incubations performed in the presence of bovine serum albumin (BSA). Five UGTs (UGT1A3, UGT2B4, UGT2B7, UGT1A9 and UGT1A8) were identified that produced abundant Ib monoglucuronide, especially UGT1A3. We investigated Ib glucuronidation in liver microsomes from different species (rat, dog, human) and in five identified major human UGTs. Ib glucuronidation in liver microsomes and recombinant human UGTs all showed substrate inhibition kinetics. DLM showed the strongest affinity and activity, HLM showed the lowest affinity, and RLM showed the weakest activity. The addition of BSA did not alter the enzyme kinetics, but significantly altered enzyme kinetic parameters resulting in a reduction in Km value and an increase in CLint value. However, high concentrations of BSA could significantly attenuate this positive effect on enzyme affinity and activity, and the effect of BSA on the Vmax of Ib glucuronidation was opposite in different enzyme sources. In conclusion, this study demonstrated the substrate inhibition kinetics of Ib glucuronidation in the liver metabolism and the effect of BSA on its kinetic parameters, in order to provide more accurate in vitro data for in vivo prediction.
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17
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Gao J, Zhou J, He XP, Zhang YF, Gao N, Tian X, Fang Y, Wen Q, Jia LJ, Jin H, Qiao HL. Changes in cytochrome P450s-mediated drug clearance in patients with hepatocellular carcinoma in vitro and in vivo: a bottom-up approach. Oncotarget 2017; 7:28612-23. [PMID: 27086920 PMCID: PMC5053749 DOI: 10.18632/oncotarget.8704] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Accepted: 03/27/2016] [Indexed: 01/21/2023] Open
Abstract
Hepatocellular carcinoma (HCC) accompanied by severe liver dysfunction is a serious disease, which results in altered hepatic clearance. Generally, maintenance doses depend upon drug clearance, so individual dosage regimens should be customized for HCC patients based on the condition of patients. Based on clearance of CYP isoform-specific substrates at the microsomal level (CLM), microsomal protein per gram of liver (MPPGL), liver weight, hepatic blood flow, hepatic clearance values (CLH) for 10 CYPs in HCC patients (n=102) were extrapolated using a predictive bottom-up pharmacokinetic model. Compared with controls, the CLM values for CYP2C9, 2D6, 2E1 were significantly increased in HCC patients. Additionally, CYP1A2, 2C8, 2C19 CLM values decreased while the values for CYP2A6, 2B6, 3A4/5 were unchanged. The MPPGL values in HCC tissues were significantly reduced. CLH values of HCC patients for CYP1A2, 2A6, 2B6, 2C8, 2C19, and 3A4/5 were significantly reduced, while this for CYP2E1 were markedly increased and those for CYP2C9 and 2D6 did not change. Moreover, disease (fibrosis and cirrhosis) and polymorphisms of the CYP genes have influenced the CLH for some CYPs. Prediction of the effects of HCC on drug clearance may be helpful for the design of clinical studies and the clinical management of drugs in HCC patients.
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Affiliation(s)
- Jie Gao
- Institute of Clinical Pharmacology, Zhengzhou University, Zhengzhou, China
| | - Jun Zhou
- Institute of Clinical Pharmacology, Zhengzhou University, Zhengzhou, China
| | - Xiao-Pei He
- Institute of Clinical Pharmacology, Zhengzhou University, Zhengzhou, China
| | - Yun-Fei Zhang
- Institute of Clinical Pharmacology, Zhengzhou University, Zhengzhou, China
| | - Na Gao
- Institute of Clinical Pharmacology, Zhengzhou University, Zhengzhou, China
| | - Xin Tian
- Institute of Clinical Pharmacology, Zhengzhou University, Zhengzhou, China
| | - Yan Fang
- Institute of Clinical Pharmacology, Zhengzhou University, Zhengzhou, China
| | - Qiang Wen
- Institute of Clinical Pharmacology, Zhengzhou University, Zhengzhou, China
| | - Lin-Jing Jia
- Institute of Clinical Pharmacology, Zhengzhou University, Zhengzhou, China
| | - Han Jin
- Institute of Clinical Pharmacology, Zhengzhou University, Zhengzhou, China
| | - Hai-Ling Qiao
- Institute of Clinical Pharmacology, Zhengzhou University, Zhengzhou, China
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18
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Palacharla RC, Uthukam V, Manoharan A, Ponnamaneni RK, Padala NP, Boggavarapu RK, Bhyrapuneni G, Ajjala DR, Nirogi R. Inhibition of cytochrome P450 enzymes by saturated and unsaturated fatty acids in human liver microsomes, characterization of enzyme kinetics in the presence of bovine serum albumin (0.1 and 1.0% w/v) and in vitro - in vivo extrapolation of hepatic clearance. Eur J Pharm Sci 2017; 101:80-89. [PMID: 28179134 DOI: 10.1016/j.ejps.2017.01.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 12/29/2016] [Accepted: 01/22/2017] [Indexed: 11/28/2022]
Abstract
The objective of the study was to determine the effect of fatty acids on CYP enzymes and the effect of BSA on intrinsic clearance of probe substrates. The inhibitory effect of thirteen fatty acids including saturated, mono-unsaturated and polyunsaturated fatty acids on CYP enzymes, kinetic parameters and intrinsic clearance values of nine CYP marker probe substrate reactions in the absence and presence of BSA (0.1 and 1.0% w/v) were characterized in human liver microsomes. The results demonstrate that most of the unsaturated fatty acids showed marked inhibition towards CYP2C8 mediated amodiaquine N-deethylation followed by inhibition of CYP2C9 and CYP2B6 mediated activities. The addition of 0.1% BSA in the incubation markedly improved the unbound intrinsic clearance values of probe substrates by reducing the Km values with little or no effect on maximal velocity. The addition of BSA (0.1 and 1.0% w/v) did not influence the unbound intrinsic clearance of marker reactions for CYP2A6, and CYP3A4 enzymes. The addition of 0.1% w/v BSA is sufficient to determine the intrinsic clearance of marker probe reactions by metabolite formation approach. The predicted hepatic clearance values for the substrates using the well-stirred model, in the presence of BSA (0.1% BSA), are comparable to the in vivo hepatic clearance values.
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Affiliation(s)
| | - Venkatesham Uthukam
- Drug Metabolism and Pharmacokinetics, Suven Life Sciences Ltd, Jeedimetla, Hyderabad, India
| | - Arunkumar Manoharan
- Drug Metabolism and Pharmacokinetics, Suven Life Sciences Ltd, Jeedimetla, Hyderabad, India
| | | | | | | | - Gopinadh Bhyrapuneni
- Drug Metabolism and Pharmacokinetics, Suven Life Sciences Ltd, Jeedimetla, Hyderabad, India
| | | | - Ramakrishna Nirogi
- Discovery Research, Suven Life Sciences Ltd, Banjara Hills, Hyderabad, India.
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19
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Advances in drug metabolism and pharmacogenetics research in Australia. Pharmacol Res 2017; 116:7-19. [DOI: 10.1016/j.phrs.2016.12.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 12/07/2016] [Accepted: 12/08/2016] [Indexed: 01/04/2023]
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20
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Rowland A, Mangoni AA, Hopkins A, Sorich MJ, Rowland A. Optimized Cocktail Phenotyping Study Protocol Using Physiological Based Pharmacokinetic Modeling and In silico Assessment of Metabolic Drug-Drug Interactions Involving Modafinil. Front Pharmacol 2017; 7:517. [PMID: 28082902 PMCID: PMC5186771 DOI: 10.3389/fphar.2016.00517] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 12/14/2016] [Indexed: 11/13/2022] Open
Abstract
In vivo cocktail pathway phenotyping (ICPP) is routinely used to assess the metabolic drug-drug interaction (mDDI) potential of new drug candidates (NDC) during drug development. However, there are a number of potential limitations to this approach and the use of validated drug cocktails and study protocols is essential. Typically ICPP mDDI studies assess only the impact of interactions following multiple postulated perpetrator doses and hence the emphasis in terms of validation of these studies has been ensuring that there are no interactions between probe substrates. Studies assessing the comparative impact of single and multiple doses of the postulated perpetrator have the potential to provide richer information regarding both the clinical impact and mechanism of mDDIs. Using modafinil as a model compound, we sought to develop an optimized ICPP mDDI study protocol to evaluate the potential magnitude and clinical relevance of mDDIs using a physiologically based pharmacokinetic modeling approach.
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Affiliation(s)
- Angela Rowland
- Department of Clinical Pharmacology, School of Medicine, Flinders University Adelaide, SA, Australia
| | - Arduino A Mangoni
- Department of Clinical Pharmacology, School of Medicine, Flinders UniversityAdelaide, SA, Australia; Precision Medicine Group, Flinders Center for Innovation in Cancer, School of Medicine, Flinders University AdelaideSA, Australia
| | - Ashley Hopkins
- Department of Clinical Pharmacology, School of Medicine, Flinders UniversityAdelaide, SA, Australia; Precision Medicine Group, Flinders Center for Innovation in Cancer, School of Medicine, Flinders University AdelaideSA, Australia
| | - Michael J Sorich
- Department of Clinical Pharmacology, School of Medicine, Flinders UniversityAdelaide, SA, Australia; Precision Medicine Group, Flinders Center for Innovation in Cancer, School of Medicine, Flinders University AdelaideSA, Australia
| | - Andrew Rowland
- Department of Clinical Pharmacology, School of Medicine, Flinders UniversityAdelaide, SA, Australia; Precision Medicine Group, Flinders Center for Innovation in Cancer, School of Medicine, Flinders University AdelaideSA, Australia
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21
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Deng F, Sjöstedt N, Kidron H. The Effect of Albumin on MRP2 and BCRP in the Vesicular Transport Assay. PLoS One 2016; 11:e0163886. [PMID: 27706255 PMCID: PMC5051865 DOI: 10.1371/journal.pone.0163886] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 09/15/2016] [Indexed: 11/18/2022] Open
Abstract
The ABC transporters multidrug resistance associated protein 2 (MRP2) and breast cancer resistance protein (BCRP) are of interest in drug development, since they affect the pharmacokinetics of several drugs. Membrane vesicle transport assays are widely used to study interactions with these proteins. Since albumin has been found to affect the kinetics of metabolic enzymes in similar membrane preparations, we investigated whether albumin affects the kinetic parameters of efflux transport. We found that albumin increased the Vmax of 5(6)-carboxy-2',7'-dichlorofluorescein (CDCF) and estradiol-17-β-D-glucuronide uptake into MRP2 vesicles in the presence of 0.1% bovine serum albumin (BSA) by 2 and 1.5-fold, respectively, while BSA increased Lucifer yellow uptake by 30% in BCRP vesicles. Km values increased slightly, but the change was not statistically significant. The effect of BSA on substrate uptake was dependent on the vesicle amount, while increasing BSA concentration did not significantly improve substrate uptake. These results indicate a minor effect of albumin on MRP2 and BCRP, but it should be considered if albumin is added to transporter assays for example as a solubilizer, since the effect may be substrate or transporter specific.
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Affiliation(s)
- Feng Deng
- Centre for Drug Research, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - Noora Sjöstedt
- Centre for Drug Research, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - Heidi Kidron
- Centre for Drug Research, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
- * E-mail:
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22
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Backman JT, Filppula AM, Niemi M, Neuvonen PJ. Role of Cytochrome P450 2C8 in Drug Metabolism and Interactions. Pharmacol Rev 2016; 68:168-241. [PMID: 26721703 DOI: 10.1124/pr.115.011411] [Citation(s) in RCA: 142] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
During the last 10-15 years, cytochrome P450 (CYP) 2C8 has emerged as an important drug-metabolizing enzyme. CYP2C8 is highly expressed in human liver and is known to metabolize more than 100 drugs. CYP2C8 substrate drugs include amodiaquine, cerivastatin, dasabuvir, enzalutamide, imatinib, loperamide, montelukast, paclitaxel, pioglitazone, repaglinide, and rosiglitazone, and the number is increasing. Similarly, many drugs have been identified as CYP2C8 inhibitors or inducers. In vivo, already a small dose of gemfibrozil, i.e., 10% of its therapeutic dose, is a strong, irreversible inhibitor of CYP2C8. Interestingly, recent findings indicate that the acyl-β-glucuronides of gemfibrozil and clopidogrel cause metabolism-dependent inactivation of CYP2C8, leading to a strong potential for drug interactions. Also several other glucuronide metabolites interact with CYP2C8 as substrates or inhibitors, suggesting that an interplay between CYP2C8 and glucuronides is common. Lack of fully selective and safe probe substrates, inhibitors, and inducers challenges execution and interpretation of drug-drug interaction studies in humans. Apart from drug-drug interactions, some CYP2C8 genetic variants are associated with altered CYP2C8 activity and exhibit significant interethnic frequency differences. Herein, we review the current knowledge on substrates, inhibitors, inducers, and pharmacogenetics of CYP2C8, as well as its role in clinically relevant drug interactions. In addition, implications for selection of CYP2C8 marker and perpetrator drugs to investigate CYP2C8-mediated drug metabolism and interactions in preclinical and clinical studies are discussed.
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Affiliation(s)
- Janne T Backman
- Department of Clinical Pharmacology, University of Helsinki (J.T.B., A.M.F., M.N., P.J.N.), and Helsinki University Hospital, Helsinki, Finland (J.T.B., M.N., P.J.N.)
| | - Anne M Filppula
- Department of Clinical Pharmacology, University of Helsinki (J.T.B., A.M.F., M.N., P.J.N.), and Helsinki University Hospital, Helsinki, Finland (J.T.B., M.N., P.J.N.)
| | - Mikko Niemi
- Department of Clinical Pharmacology, University of Helsinki (J.T.B., A.M.F., M.N., P.J.N.), and Helsinki University Hospital, Helsinki, Finland (J.T.B., M.N., P.J.N.)
| | - Pertti J Neuvonen
- Department of Clinical Pharmacology, University of Helsinki (J.T.B., A.M.F., M.N., P.J.N.), and Helsinki University Hospital, Helsinki, Finland (J.T.B., M.N., P.J.N.)
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23
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Nair PC, McKinnon RA, Miners JO. A Fragment-Based Approach for the Computational Prediction of the Nonspecific Binding of Drugs to Hepatic Microsomes. ACTA ACUST UNITED AC 2016; 44:1794-1798. [PMID: 27543205 DOI: 10.1124/dmd.116.071852] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2016] [Accepted: 08/18/2016] [Indexed: 11/22/2022]
Abstract
Correction for the nonspecific binding (NSB) of drugs to liver microsomes is essential for the accurate measurement of the kinetic parameters Km and Ki, and hence in vitro-in vivo extrapolation to predict hepatic clearance and drug-drug interaction potential. Although a number of computational approaches for the estimation of drug microsomal NSB have been published, they generally rely on compound lipophilicity and charge state at the expense of other physicochemical and chemical properties. In this work, we report the development of a fragment-based hologram quantitative structure activity relationship (HQSAR) approach for the prediction of NSB using a database of 132 compounds. The model has excellent predictivity, with a noncross-validated r2 of 0.966 and cross-validated r2 of 0.680, with a predictive r2 of 0.748 for an external test set comprising 34 drugs. The HQSAR method reliably predicted the fraction unbound in incubations of 95% of the training and test set drugs, excluding compounds with a steroid or morphinan 4,5-epoxide nucleus. Using the same data set of compounds, performance of the HQSAR method was superior to a model based on logP/D as the sole descriptor (predictive r2 for the test set compounds, 0.534). Thus, the HQSAR method provides an alternative approach to laboratory-based procedures for the prediction of the NSB of drugs to liver microsomes, irrespective of the drug charge state (acid, base, or neutral).
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Affiliation(s)
- Pramod C Nair
- Department of Clinical Pharmacology (P.C.N., J.O.M.) and Flinders Centre for Innovation in Cancer (P.C.N., R.A.M., J.O.M.), School of Medicine, Flinders University, Adelaide, Australia
| | - Ross A McKinnon
- Department of Clinical Pharmacology (P.C.N., J.O.M.) and Flinders Centre for Innovation in Cancer (P.C.N., R.A.M., J.O.M.), School of Medicine, Flinders University, Adelaide, Australia
| | - John O Miners
- Department of Clinical Pharmacology (P.C.N., J.O.M.) and Flinders Centre for Innovation in Cancer (P.C.N., R.A.M., J.O.M.), School of Medicine, Flinders University, Adelaide, Australia
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24
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Poulin P, Burczynski FJ, Haddad S. The Role of Extracellular Binding Proteins in the Cellular Uptake of Drugs: Impact on Quantitative In Vitro-to-In Vivo Extrapolations of Toxicity and Efficacy in Physiologically Based Pharmacokinetic-Pharmacodynamic Research. J Pharm Sci 2016; 105:497-508. [PMID: 26173749 DOI: 10.1002/jps.24571] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 06/18/2015] [Accepted: 06/18/2015] [Indexed: 01/10/2023]
Abstract
A critical component in the development of physiologically based pharmacokinetic-pharmacodynamic (PBPK/PD) models for estimating target organ dosimetry in pharmacology and toxicology studies is the understanding of the uptake kinetics and accumulation of drugs and chemicals at the cellular level. Therefore, predicting free drug concentrations in intracellular fluid will contribute to our understanding of concentrations at the site of action in cells in PBPK/PD research. Some investigators believe that uptake of drugs in cells is solely driven by the unbound fraction; conversely, others argue that the protein-bound fraction contributes a significant portion of the total amount delivered to cells. Accordingly, the current literature suggests the existence of a so-called albumin-mediated uptake mechanism(s) for the protein-bound fraction (i.e., extracellular protein-facilitated uptake mechanisms) at least in hepatocytes and cardiac myocytes; however, such mechanism(s) and cells from other organs deserve further exploration. Therefore, the main objective of this present study was to discuss further the implication of potential protein-facilitated uptake mechanism(s) on drug distribution in cells under in vivo conditions. The interplay between the protein-facilitated uptake mechanism(s) and the effects of a pH gradient, metabolism, transport, and permeation limitation potentially occurring in cells was also discussed, as this should violate the basic assumption on similar free drug concentration in cells and plasma. This was made because the published equations used to calculate drug concentrations in cells in a PBPK/PD model did not consider potential protein-facilitated uptake mechanism(s). Consequently, we corrected some published equations for calculating the free drug concentrations in cells compared with plasma in PBPK/PD modeling studies, and we proposed a refined strategy for potentially performing more accurate quantitative in vitro-to-in vivo extrapolations (IVIVEs) of toxicity (efficacy) at the cellular level from data generated in cell assays. Overall, this present study may help to optimize the human dose prediction in preclinical and clinical studies, while prescribing drugs with narrow therapeutic windows that are highly bound to extracellular proteins and/or highly ionized at the physiological pH. This may facilitate building a more accurate safety (efficacy) profile for such drugs.
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Affiliation(s)
- Patrick Poulin
- Consultant, Québec city, Québec, Canada; Department of Occupational and Environmental Health, School of Public Health, IRSPUM, Université de Montréal, Québec, Canada.
| | - Frank J Burczynski
- Department of Pharmacology and Therapeutics, Faculty of Pharmacy, University of Manitoba, Manitoba, Canada
| | - Sami Haddad
- Department of Occupational and Environmental Health, School of Public Health, IRSPUM, Université de Montréal, Québec, Canada
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25
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Sekiguchi K, Kanazu T, Murayama N, Yamazaki H, Yamaguchi Y. In vitroinhibition and enhancement of liver microsomal S-777469 metabolism by long-chain fatty acids and serum albumin: insight intoin vitroandin vivodiscrepancy of metabolite formation in humans. Xenobiotica 2015; 46:495-502. [DOI: 10.3109/00498254.2015.1091114] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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26
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Korprasertthaworn P, Polasek TM, Sorich MJ, McLachlan AJ, Miners JO, Tucker GT, Rowland A. In Vitro Characterization of the Human Liver Microsomal Kinetics and Reaction Phenotyping of Olanzapine Metabolism. Drug Metab Dispos 2015; 43:1806-14. [DOI: 10.1124/dmd.115.064790] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 08/31/2015] [Indexed: 12/11/2022] Open
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27
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Khan MS, Barratt DT, Somogyi AA. Impact of CYP2C8*3 polymorphism on in vitro metabolism of imatinib to N-desmethyl imatinib. Xenobiotica 2015; 46:278-87. [PMID: 26161459 DOI: 10.3109/00498254.2015.1060649] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
1. Imatinib is metabolized to N-desmethyl imatinib by CYPs 3A4 and 2C8. The effect of CYP2C8*3 genotype on N-desmethyl imatinib formation was unknown. 2. We examined imatinib N-demethylation in human liver microsomes (HLMs) genotyped for CYP2C8*3, in CYP2C8*3/*3 pooled HLMs and in recombinant CYP2C8 and CYP3A4 enzymes. Effects of CYP-selective inhibitors on N-demethylation were also determined. 3. A single-enzyme Michaelis-Menten model with autoinhibition best fitted CYP2C8*1/*1 HLM (n = 5) and recombinant CYP2C8 kinetic data (median ± SD Ki = 139 ± 61 µM and 149 µM, respectively). Recombinant CYP3A4 showed two-site enzyme kinetics with no autoinhibition. Three of four CYP2C8*1/*3 HLMs showed single-enzyme kinetics with no autoinhibition. Binding affinity was higher in CYP2C8*1/*3 than CYP2C8*1/*1 HLM (median ± SD Km = 6 ± 2 versus 11 ± 2 µM, P=0.04). CYP2C8*3/*3 (pooled HLM) also showed high binding affinity (Km = 4 µM) and single-enzyme weak autoinhibition (Ki = 449 µM) kinetics. CYP2C8 inhibitors reduced HLM N-demethylation by 47-75%, compared to 0-30% for CYP3A4 inhibitors. 4. In conclusion, CYP2C8*3 is a gain-of-function polymorphism for imatinib N-demethylation, which appears to be mainly mediated by CYP2C8 and not CYP3A4 in vitro in HLM.
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Affiliation(s)
- Muhammad Suleman Khan
- a Discipline of Pharmacology, School of Medical Sciences, University of Adelaide , Adelaide , Australia and
| | - Daniel T Barratt
- a Discipline of Pharmacology, School of Medical Sciences, University of Adelaide , Adelaide , Australia and.,b Centre for Personalised Cancer Medicine, University of Adelaide , Adelaide , Australia
| | - Andrew A Somogyi
- a Discipline of Pharmacology, School of Medical Sciences, University of Adelaide , Adelaide , Australia and.,b Centre for Personalised Cancer Medicine, University of Adelaide , Adelaide , Australia
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Wang N, Wang F, Meng Y, Yang GH, Chen JW, Wang JX. Albumin Supplement Affects the Metabolism and Metabolism-Related Drug-Drug Interaction of Fenoprofen Enantiomers. Chirality 2015; 27:436-40. [PMID: 26037509 DOI: 10.1002/chir.22462] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 03/08/2015] [Accepted: 04/10/2015] [Indexed: 11/11/2022]
Affiliation(s)
- Nan Wang
- Department of Emergency; First Affiliated Hospital of Zhengzhou University; Zhengzhou Henan China
| | - Feng Wang
- Department of Orthopaedic Surgery; Shanghai Jiao Tong University Affiliated Sixth People's Hospital
| | - Yu Meng
- Department of Emergency; First Affiliated Hospital of Zhengzhou University; Zhengzhou Henan China
| | - Guo-Hui Yang
- Department of Emergency; First Affiliated Hospital of Zhengzhou University; Zhengzhou Henan China
| | - Ju-Wu Chen
- Department of Emergency; First Affiliated Hospital of Zhengzhou University; Zhengzhou Henan China
| | - Jia-Xiang Wang
- Department of Pediatric Surgery; First Affiliated Hospital of Zhengzhou University; Zhengzhou Henan China
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Peng Y, Wu H, Zhang X, Zhang F, Qi H, Zhong Y, Wang Y, Sang H, Wang G, Sun J. A comprehensive assay for nine major cytochrome P450 enzymes activities with 16 probe reactions on human liver microsomes by a single LC/MS/MS run to support reliablein vitroinhibitory drug–drug interaction evaluation. Xenobiotica 2015; 45:961-77. [DOI: 10.3109/00498254.2015.1036954] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Kandel SE, Lampe JN. Role of protein-protein interactions in cytochrome P450-mediated drug metabolism and toxicity. Chem Res Toxicol 2014; 27:1474-86. [PMID: 25133307 PMCID: PMC4164225 DOI: 10.1021/tx500203s] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
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Through their unique oxidative chemistry,
cytochrome P450 monooxygenases
(CYPs) catalyze the elimination of most drugs and toxins from the
human body. Protein–protein interactions play a critical role
in this process. Historically, the study of CYP–protein interactions
has focused on their electron transfer partners and allosteric mediators,
cytochrome P450 reductase and cytochrome b5. However, CYPs can bind
other proteins that also affect CYP function. Some examples include
the progesterone receptor membrane component 1, damage resistance
protein 1, human and bovine serum albumin, and intestinal fatty acid
binding protein, in addition to other CYP isoforms. Furthermore, disruption
of these interactions can lead to altered paths of metabolism and
the production of toxic metabolites. In this review, we summarize
the available evidence for CYP protein–protein interactions
from the literature and offer a discussion of the potential impact
of future studies aimed at characterizing noncanonical protein–protein
interactions with CYP enzymes.
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Affiliation(s)
- Sylvie E Kandel
- XenoTech, LLC , 16825 West 116th Street, Lenexa, Kansas 66219, United States
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Wang Y, Wang M, Qi H, Pan P, Hou T, Li J, He G, Zhang H. Pathway-Dependent Inhibition of Paclitaxel Hydroxylation by Kinase Inhibitors and Assessment of Drug–Drug Interaction Potentials. Drug Metab Dispos 2014; 42:782-95. [DOI: 10.1124/dmd.113.053793] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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Kadono K, Koakutsu A, Naritomi Y, Terashita S, Tabata K, Teramura T. Comparison of intestinal metabolism of CYP3A substrates between rats and humans: application of portal–systemic concentration difference method. Xenobiotica 2013; 44:511-21. [DOI: 10.3109/00498254.2013.869375] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Poulin P, Haddad S. Toward a new paradigm for the efficient in vitro–in vivo extrapolation of metabolic clearance in humans from hepatocyte data. J Pharm Sci 2013; 102:3239-51. [DOI: 10.1002/jps.23502] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Revised: 02/19/2013] [Accepted: 02/20/2013] [Indexed: 01/18/2023]
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Poulin P. Prediction of Total Hepatic Clearance by Combining Metabolism, Transport, and Permeability Data in the In Vitro–In Vivo Extrapolation Methods: Emphasis on an Apparent Fraction Unbound in Liver for Drugs. J Pharm Sci 2013; 102:2085-95. [DOI: 10.1002/jps.23562] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Revised: 04/09/2013] [Accepted: 04/09/2013] [Indexed: 12/14/2022]
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35
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Yu L, Shi D, Ma L, Zhou Q, Zeng S. Influence ofCYP2C8polymorphisms on the hydroxylation metabolism of paclitaxel, repaglinide and ibuprofen enantiomersin vitro. Biopharm Drug Dispos 2013; 34:278-87. [DOI: 10.1002/bdd.1842] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2012] [Revised: 02/04/2013] [Accepted: 03/18/2013] [Indexed: 12/22/2022]
Affiliation(s)
- Lushan Yu
- Laboratory of Pharmaceutical Analysis and Drug Metabolism, College of Pharmaceutical Sciences; Zhejiang University; Hangzhou; 310058; China
| | - Da Shi
- Laboratory of Pharmaceutical Analysis and Drug Metabolism, College of Pharmaceutical Sciences; Zhejiang University; Hangzhou; 310058; China
| | - Liping Ma
- Laboratory of Pharmaceutical Analysis and Drug Metabolism, College of Pharmaceutical Sciences; Zhejiang University; Hangzhou; 310058; China
| | - Quan Zhou
- Department of Pharmacy, the 2nd Affiliated Hospital, School of Medicine; Zhejiang University; Zhejiang; Zhejiang Province; China
| | - Su Zeng
- Laboratory of Pharmaceutical Analysis and Drug Metabolism, College of Pharmaceutical Sciences; Zhejiang University; Hangzhou; 310058; China
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36
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Jia T, Carrero JJ, Lindholm B, Stenvinkel P. The complex role of adiponectin in chronic kidney disease. Biochimie 2012; 94:2150-6. [DOI: 10.1016/j.biochi.2012.02.024] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Accepted: 02/17/2012] [Indexed: 12/25/2022]
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37
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Poulin P, Hop CECA, Ho Q, Halladay JS, Haddad S, Kenny JR. Comparative assessment of In Vitro-In Vivo extrapolation methods used for predicting hepatic metabolic clearance of drugs. J Pharm Sci 2012; 101:4308-26. [PMID: 22890957 DOI: 10.1002/jps.23288] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Revised: 06/26/2012] [Accepted: 07/17/2012] [Indexed: 02/06/2023]
Abstract
The purpose of this study was to perform a comparative analysis of various in vitro--in vivo extrapolation (IVIVE) methods used for predicting hepatic metabolic clearance (CL) of drugs on the basis of intrinsic CL data determined in microsomes. Five IVIVE methods were evaluated: the "conventional and conventional bias-corrected methods" using the unbound fraction in plasma (fu(p) ), the "Berezhkovskiy method" in which the fu(p) is adjusted for drug ionization, the "Poulin et al. method" using the unbound fraction in liver (fu(liver) ), and the "direct scaling method," which does not consider any binding corrections. We investigated the effects of the following scenarios on the prediction of CL: the use of preclinical or human datasets, the extent of plasma protein binding, the magnitude of CL in vivo, and the extent of drug disposition based on biopharmaceutics drug disposition classification system (BDDCS) categorization. A large and diverse dataset of 139 compounds was collected, including those from the literature and in house from Genentech. The results of this study confirm that the Poulin et al. method is robust and showed the greatest accuracy as compared with the other IVIVE methods in the majority of prediction scenarios studied here. The difference across the prediction methods is most pronounced for (a) albumin-bound drugs, (b) highly bound drugs, and (c) low CL drugs. Predictions of CL showed relevant interspecies differences for BDDCS class 2 compounds; the direct scaling method showed the greatest predictivity for these compounds, particularly for a reduced dataset in rat that have unexpectedly high CL in vivo. This result is a reflection of the direct scaling method's natural tendency to overpredict the true metabolic CL. Overall, this study should facilitate the use of IVIVE correlation methods in physiologically based pharmacokinetics (PBPK) model.
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Affiliation(s)
- Patrick Poulin
- Consultant, 4009 Sylvia Daoust, Québec City, Québec G1X 0A6, Canada.
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Honkalammi J, Niemi M, Neuvonen PJ, Backman JT. Gemfibrozil Is a Strong Inactivator of CYP2C8 in Very Small Multiple Doses. Clin Pharmacol Ther 2012; 91:846-55. [DOI: 10.1038/clpt.2011.313] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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39
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Wattanachai N, Tassaneeyakul W, Rowland A, Elliot DJ, Bowalgaha K, Knights KM, Miners JO. Effect of Albumin on Human Liver Microsomal and Recombinant CYP1A2 Activities: Impact on In Vitro-In Vivo Extrapolation of Drug Clearance. Drug Metab Dispos 2012; 40:982-9. [DOI: 10.1124/dmd.111.044057] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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40
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Yoda N, Emoto C, Date S, Kondo S, Miyake M, Nakazato S, Umehara K, Kashiyama E. Characterization of intestinal and hepatic P450 enzymes in cynomolgus monkeys with typical substrates and inhibitors for human P450 enzymes. Xenobiotica 2012; 42:719-30. [DOI: 10.3109/00498254.2012.656732] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Shaffer CL, Scialis RJ, Rong H, Obach RS. Using Simcyp to project human oral pharmacokinetic variability in early drug research to mitigate mechanism-based adverse events. Biopharm Drug Dispos 2012; 33:72-84. [PMID: 22213407 DOI: 10.1002/bdd.1768] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Revised: 12/20/2011] [Accepted: 12/22/2011] [Indexed: 12/15/2022]
Abstract
Positive allosteric modulators ('potentiators') of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) have been shown to display a mechanism-based exposure-response continuum in preclinical species with procognitive electrophysiological and behavioral effects ('efficacy') at low exposures and motor coordination disruptions at progressively higher exposures. Due to the dose-capping nature of such motor coordination deficits, an exposure threshold-mediated adverse event (C(AE) ), the adequacy of separation between the maximal total plasma compound concentration (C(max) ) at a predicted clinically efficacious oral dose and this adverse event (AE) was explored in early drug research with three AMPAR potentiators considered potential candidates for clinical trials. In vitro metabolism studies in human liver microsomes and human hepatocytes demonstrated the metabolic clearance for each compound was predominately due to cytochromes P450 (CYP). Thus, for each compound's anticipated clinically efficacious dose, human C(max) variability following oral administration was assessed using Simcyp software, which combines its virtual human populations database using extensive demographic, physiological and genomic information with routinely collected compound-specific in vitro biochemical data to simulate and predict drug disposition. Using a combination of experimentally determined recombinant human CYP intrinsic clearances for CYP1A2, CYP2C8, CYP2C9, CYP2C19, CYP2D6 and CYP3A4, human binding factors, expected fraction absorbed and estimated steady-state volume of distribution, Simcyp simulations demonstrated that two of the three potentiators had acceptable projected C(max) variability (i.e. the 95th percentile C(max) did not breach C(AE) ). This evaluation aided in the selection of compounds for preclinical progression, and represents a novel application of pharmacologically based pharmacokinetic (PBPK) software approaches to predict interpatient variability.
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Affiliation(s)
- Christopher L Shaffer
- Department of Pharmacokinetics, Pharmacodynamics and Metabolism, Pfizer Global Research and Development, Groton Laboratories, Pfizer Inc., Groton, CT 06340, USA.
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