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Chen J, Yuan Z, Tu Y, Hu W, Xie C, Ye L. Experimental and computational models to investigate intestinal drug permeability and metabolism. Xenobiotica 2023; 53:25-45. [PMID: 36779684 DOI: 10.1080/00498254.2023.2180454] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Oral administration is the preferred route for drug administration that leads to better therapy compliance. The intestine plays a key role in the absorption and metabolism of oral drugs, therefore, new intestinal models are being continuously proposed, which contribute to the study of intestinal physiology, drug screening, drug side effects, and drug-drug interactions.Advances in pharmaceutical processes have produced more drug formulations, causing challenges for intestinal models. To adapt to the rapid evolution of pharmaceuticals, more intestinal models have been created. However, because of the complexity of the intestine, few models can take all aspects of the intestine into account, and some functions must be sacrificed to investigate other areas. Therefore, investigators need to choose appropriate models according to the experimental stage and other requirements to obtain the desired results.To help researchers achieve this goal, this review summarised the advantages and disadvantages of current commonly used intestinal models and discusses possible future directions, providing a better understanding of intestinal models.
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Affiliation(s)
- Jinyuan Chen
- Institute of Scientific Research, Southern Medical University, Guangzhou, P.R. China.,TCM-Integrated Hospital, Southern Medical University, Guangzhou, P.R. China
| | - Ziyun Yuan
- NMPA Key Laboratory for Research and Evaluation of Drug Metabolism, Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, P.R. China
| | - Yifan Tu
- Boehringer-Ingelheim, Connecticut, P.R. USA
| | - Wanyu Hu
- NMPA Key Laboratory for Research and Evaluation of Drug Metabolism, Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, P.R. China
| | - Cong Xie
- Clinical Pharmacy Center, Nanfang Hospital, Southern Medical University, Guangzhou, P.R. China
| | - Ling Ye
- TCM-Integrated Hospital, Southern Medical University, Guangzhou, P.R. China
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2
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George B, Lumen A, Nguyen C, Wesley B, Wang J, Beitz J, Crentsil V. Application of physiologically based pharmacokinetic modeling for sertraline dosing recommendations in pregnancy. NPJ Syst Biol Appl 2020; 6:36. [PMID: 33159093 PMCID: PMC7648747 DOI: 10.1038/s41540-020-00157-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 10/02/2020] [Indexed: 01/26/2023] Open
Abstract
Pregnancy is a period of significant change that impacts physiological and metabolic status leading to alterations in the disposition of drugs. Uncertainty in drug dosing in pregnancy can lead to suboptimal therapy, which can contribute to disease exacerbation. A few studies show there are increased dosing requirements for antidepressants in late pregnancy; however, the quantitative data to guide dose adjustments are sparse. We aimed to develop a physiologically based pharmacokinetic (PBPK) model that allows gestational-age dependent prediction of sertraline dosing in pregnancy. A minimal physiological model with defined gut, liver, plasma, and lumped placental-fetal compartments was constructed using the ordinary differential equation solver package, ‘mrgsolve’, in R. We extracted data from the literature to parameterize the model, including sertraline physicochemical properties, in vitro metabolism studies, disposition in nonpregnant women, and physiological changes during pregnancy. The model predicted the pharmacokinetic parameters from a clinical study with eight subjects for the second trimester and six subjects for the third trimester. Based on the model, gestational-dependent changes in physiology and metabolism account for increased clearance of sertraline (up to 143% at 40 weeks gestational age), potentially leading to under-dosing of pregnant women when nonpregnancy doses are used. The PBPK model was converted to a prototype web-based interactive dosing tool to demonstrate how the output of a PBPK model may translate into optimal sertraline dosing in pregnancy. Quantitative prediction of drug exposure using PBPK modeling in pregnancy will support clinically appropriate dosing and increase the therapeutic benefit for pregnant women.
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Affiliation(s)
- Blessy George
- Center for Drug Evaluation and Research, U.S. FDA, Silver Spring, MD, USA.,Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA
| | - Annie Lumen
- National Center for Toxicological Research, U.S. FDA, Jefferson, AR, USA
| | - Christine Nguyen
- Center for Drug Evaluation and Research, U.S. FDA, Silver Spring, MD, USA
| | - Barbara Wesley
- Center for Drug Evaluation and Research, U.S. FDA, Silver Spring, MD, USA
| | - Jian Wang
- Center for Drug Evaluation and Research, U.S. FDA, Silver Spring, MD, USA
| | - Julie Beitz
- Center for Drug Evaluation and Research, U.S. FDA, Silver Spring, MD, USA
| | - Victor Crentsil
- Center for Drug Evaluation and Research, U.S. FDA, Silver Spring, MD, USA.
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The Segregated Intestinal Flow Model (SFM) for Drug Absorption and Drug Metabolism: Implications on Intestinal and Liver Metabolism and Drug-Drug Interactions. Pharmaceutics 2020; 12:pharmaceutics12040312. [PMID: 32244748 PMCID: PMC7238003 DOI: 10.3390/pharmaceutics12040312] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 03/26/2020] [Accepted: 03/27/2020] [Indexed: 12/13/2022] Open
Abstract
The properties of the segregated flow model (SFM), which considers split intestinal flow patterns perfusing an active enterocyte region that houses enzymes and transporters (<20% of the total intestinal blood flow) and an inactive serosal region (>80%), were compared to those of the traditional model (TM), wherein 100% of the flow perfuses the non-segregated intestine tissue. The appropriateness of the SFM model is important in terms of drug absorption and intestinal and liver drug metabolism. Model behaviors were examined with respect to intestinally (M1) versus hepatically (M2) formed metabolites and the availabilities in the intestine (FI) and liver (FH) and the route of drug administration. The %contribution of the intestine to total first-pass metabolism bears a reciprocal relation to that for the liver, since the intestine, a gateway tissue, regulates the flow of substrate to the liver. The SFM predicts the highest and lowest M1 formed with oral (po) and intravenous (iv) dosing, respectively, whereas the extent of M1 formation is similar for the drug administered po or iv according to the TM, and these values sit intermediate those of the SFM. The SFM is significant, as this drug metabolism model explains route-dependent intestinal metabolism, describing a higher extent of intestinal metabolism with po versus the much reduced or absence of intestinal metabolism with iv dosing. A similar pattern exists for drug–drug interactions (DDIs). The inhibitor or inducer exerts its greatest effect on victim drugs when both inhibitor/inducer and drug are given po. With po dosing, more drug or inhibitor/inducer is brought into the intestine for DDIs. The bypass of flow and drug to the enterocyte region of the intestine after intravenous administration adds complications to in vitro–in vivo extrapolations (IVIVE).
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Noh K, Pang KS. Theoretical consideration of the properties of intestinal flow models on route-dependent drug removal: Segregated Flow (SFM) vs. Traditional (TM). Biopharm Drug Dispos 2020; 40:195-213. [PMID: 31099032 DOI: 10.1002/bdd.2184] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 04/21/2019] [Accepted: 04/30/2019] [Indexed: 12/28/2022]
Abstract
The intestine is endowed with a plethora of enzymes and transporters and regulates the flow of substrate to the liver. Physiologically-based pharmacokinetic models have surfaced to describe intestinal removal. The traditional model (TM) describes the intestinal flow as a whole perfusing the entire tissue that contains the intestinal transporters and enzymes. The segregated flow model (SFM) describes that only a fraction (fQ < 0.2) of the intestinal blood flow perfuses the enterocyte region where the intestinal enzymes and transporters are housed, rendering a lower drug distribution/intestinal clearance when drug enters via the circulation than from the gut lumen. As shown by simulations, a higher intestinal clearance and extraction ratio (EI,iv ) exists for the TM than for SFM after iv dosing. By contrast, the EI,po after po dosing is higher for the SFM, due to the smaller volume of distribution for the enterocyte region and a lower flow rate that result in increased mean residence time and higher drug extraction. Under MBI (mechanism-based inhibition), the AUCR,po after oral bolus is the highest for drug when inhibitor is given orally, with SFM > TM. Competitive inhibition of intestinal enzymes leads to higher liver metabolism; again, when both drug and inhibitor are given orally, changes in the SFM > TM. However, less definitive patterns result with inhibition of both intestinal and liver enzymes. In conclusion, differences exist for EI and drug-drug interaction (DDI) between the TM and SFM. The fractional intestinal blood flow (fQ ) is a key factor affecting different extents of intestinal/liver metabolism of the drug after oral as well as intravenous administration.
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Affiliation(s)
- Keumhan Noh
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, M5S 3M2, Canada
| | - K Sandy Pang
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, M5S 3M2, Canada
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Heinig R, Gerisch M, Engelen A, Nagelschmitz J, Loewen S. Pharmacokinetics of the Novel, Selective, Non-steroidal Mineralocorticoid Receptor Antagonist Finerenone in Healthy Volunteers: Results from an Absolute Bioavailability Study and Drug-Drug Interaction Studies In Vitro and In Vivo. Eur J Drug Metab Pharmacokinet 2019; 43:715-727. [PMID: 29779093 DOI: 10.1007/s13318-018-0483-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND AND OBJECTIVES Finerenone is a selective, non-steroidal mineralocorticoid receptor antagonist. In vivo and in vitro studies were performed to assess absolute bioavailability of finerenone, the effect of metabolic enzyme inhibitors on the pharmacokinetics of finerenone and its metabolites, the quantitative contribution of the involved enzymes cytochrome P450 (CYP) 3A4 and CYP2C8 and the relevance of gut wall versus liver metabolism. METHODS The pharmacokinetics, safety and tolerability of finerenone (1.25-10 mg orally or 0.25-1.0 mg intravenously) were evaluated in healthy male volunteers in four crossover studies. Absolute bioavailability was assessed in volunteers receiving finerenone orally and by intravenous infusion (n = 15) and the effects of erythromycin (n = 15), verapamil (n = 13) and gemfibrozil (n = 16) on finerenone pharmacokinetics were investigated. Finerenone was also incubated with cryopreserved human hepatocytes in vitro in the presence of erythromycin, verapamil or gemfibrozil. RESULTS Finerenone absolute bioavailability was 43.5% due to first-pass metabolism in the gut wall and liver. The geometric mean AUC0-∞ ratios of finerenone (drug + inhibitor/drug alone) were 3.48, 2.70 and 1.10 with erythromycin, verapamil and gemfibrozil, respectively. The contribution ratio of CYP3A4 to the metabolic clearance of finerenone derived from these values was 0.88-0.89 and was consistent with estimations based on in vitro data, with the remaining metabolic clearance due to CYP2C8 involvement. CONCLUSION Finerenone is predominantly metabolized by CYP3A4 in the gut wall and liver. Increases in systemic exposure upon concomitant administration of inhibitors of this isoenzyme are predictable and consistent with in vitro data. Inhibition of CYP2C8, the second involved metabolic enzyme, has no relevant effect on finerenone in vivo.
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Affiliation(s)
- Roland Heinig
- Bayer AG, Research and Development, Pharmaceuticals, Clinical Sciences, Wuppertal, Germany.
| | - Michael Gerisch
- Bayer AG, Research and Development, Pharmaceuticals, DMPK, Wuppertal, Germany
| | - Anna Engelen
- Bayer AG, Research and Development, Pharmaceuticals, DMPK, Wuppertal, Germany
| | - Johannes Nagelschmitz
- Bayer AG, Research and Development, Pharmaceuticals, Clinical Sciences, Wuppertal, Germany
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Pharmacokinetics, Tissue Distribution and Excretion of a Novel Diuretic (PU-48) in Rats. Pharmaceutics 2018; 10:pharmaceutics10030124. [PMID: 30096833 PMCID: PMC6160999 DOI: 10.3390/pharmaceutics10030124] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 07/21/2018] [Accepted: 07/27/2018] [Indexed: 01/02/2023] Open
Abstract
Methyl 3-amino-6-methoxythieno [2,3-b] quinoline-2-carboxylate (PU-48) is a novel diuretic urea transporter inhibitor. The aim of this study is to investigate the profile of plasma pharmacokinetics, tissue distribution, and excretion by oral dosing of PU-48 in rats. Concentrations of PU-48 within biological samples are determined using a validated high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. After oral administration of PU-48 (3, 6, and 12 mg/kg, respectively) in self-nanomicroemulsifying drug delivery system (SNEDDS) formulation, the peak plasma concentrations (Cmax), and the area under the curve (AUC0⁻∞) were increased by the dose-dependent and linear manner, but the marked different of plasma half-life (t1/2) were not observed. This suggests that the pharmacokinetic profile of PU-48 prototype was first-order elimination kinetic characteristics within the oral three doses range in rat plasma. Moreover, the prototype of PU-48 was rapidly and extensively distributed into thirteen tissues, especially higher concentrations were detected in stomach, intestine, liver, kidney, and bladder. The total accumulative excretion of PU-48 in the urine, feces, and bile was less than 2%. This research is the first report on disposition via oral administration of PU-48 in rats, and it provides important information for further development of PU-48 as a diuretic drug candidate.
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Yang QJ, Bukuroshi P, Quach HP, Chow ECY, Pang KS. Highlighting Vitamin D Receptor-Targeted Activities of 1 α,25-Dihydroxyvitamin D 3 in Mice via Physiologically Based Pharmacokinetic-Pharmacodynamic Modeling. Drug Metab Dispos 2017; 46:75-87. [PMID: 29084783 DOI: 10.1124/dmd.117.077271] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 10/26/2017] [Indexed: 01/09/2023] Open
Abstract
We expanded our published physiologically based pharmacokinetic model (PBPK) on 1α,25-dihydroxyvitamin D3 [1,25(OH)2D3], ligand of the vitamin D receptor (VDR), to appraise VDR-mediated pharmacodynamics in mice. Since 1,25(OH)2D3 kinetics was best described by a segregated-flow intestinal model (SFM) that described a low/partial intestinal (blood/plasma) flow to enterocytes, with feedback regulation of its synthesis (Cyp27b1) and degradation (Cyp24a1) enzymes, this PBPK(SFM) model was expanded to describe the VDR-mediated changes (altered/basal mRNA expression) of target genes/responses with the indirect response model. We examined data on 1) renal Trpv5 (transient receptor potential cation channel, subfamily V member 5) and Trpv6 and intestinal Trpv6 (calcium channels) for calcium absorption; 2) liver 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (Hmgcr) and cytochrome 7α-hydroxylase (Cyp7a1) for cholesterol synthesis and degradation, respectively; and 3) renal and brain Mdr1 (multidrug-resistance protein that encodes the P-glycoprotein) for digoxin disposition after repetitive intraperitoneal doses of 120 pmol 1,25(OH)2D3 Fitting, performed with modeling software, yielded reasonable prediction of a dominant role of intestinal Trpv6 in calcium absorption, circadian rhythm that is characterized by simple cosine models for Hmgcr and Cyp7a1 on liver cholesterol, and brain and renal Mdr1 on tissue efflux of digoxin. Fitted parameters on the Emax, EC50, and turnover rate constants of VDR-target genes [zero-order production (kin) and first-order degradation (kout) rate constants] showed low coefficients of variation and acceptable median prediction errors (4.5%-40.6%). Sensitivity analyses showed that the Emax and EC50 values are key parameters that could influence the pharmacodynamic responses. In conclusion, the PBPK(SFM)-pharmacodynamic model successfully characterized VDR gene activation and serves as a useful tool to predict the therapeutic effects of 1,25(OH)2D3.
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Affiliation(s)
- Qi Joy Yang
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Paola Bukuroshi
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Holly P Quach
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Edwin C Y Chow
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - K Sandy Pang
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
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Rostami-Hodjegan A, Tamai I, Pang KS. Revisiting the role of gut wall in the fate of orally administered drugs: Why now and to what effect? Biopharm Drug Dispos 2017; 38:87-93. [DOI: 10.1002/bdd.2071] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
| | - Ikumi Tamai
- Faculty of Pharmaceutical Sciences, Institute of Medical; Pharmaceutical and Health Sciences, Kanazawa University; Kanazawa Japan
| | - K. Sandy Pang
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy; University of Toronto; Canada
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Ge S, Wei Y, Yin T, Xu B, Gao S, Hu M. Transport–Glucuronidation Classification System and PBPK Modeling: New Approach To Predict the Impact of Transporters on Disposition of Glucuronides. Mol Pharm 2017; 14:2884-2898. [DOI: 10.1021/acs.molpharmaceut.6b00941] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Shufan Ge
- Department
of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, The University of Houston, 1441 Moursund Street, Houston, Texas 77030, United States
| | - Yingjie Wei
- Key
Laboratory of New Drug Delivery System of Chinese Materia Medica, Jiangsu Provincial Academy of Chinese Medicine, 100 Shizi Street, Nanjing 210028, China
| | - Taijun Yin
- Department
of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, The University of Houston, 1441 Moursund Street, Houston, Texas 77030, United States
| | - Beibei Xu
- Department
of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, The University of Houston, 1441 Moursund Street, Houston, Texas 77030, United States
| | - Song Gao
- Department
of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, The University of Houston, 1441 Moursund Street, Houston, Texas 77030, United States
| | - Ming Hu
- Department
of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, The University of Houston, 1441 Moursund Street, Houston, Texas 77030, United States
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Noh K, Chen S, Yang QJ, Pang KS. Physiologically based pharmacokinetic modeling revealed minimal codeine intestinal metabolism in first-pass removal in rats. Biopharm Drug Dispos 2017; 38:50-74. [PMID: 27925239 DOI: 10.1002/bdd.2051] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 10/14/2016] [Accepted: 12/01/2016] [Indexed: 01/03/2023]
Abstract
The physiologically based model with segregated flow to the intestine (SFM-PBPK; partial, lower flow to enterocyte region vs. greater flow to serosal region) was found to describe the first-pass glucuronidation of morphine (M) to morphine-3β-glucuronide (MG) in rats after intraduodenal (i.d.) and intravenous (i.v.) administration better than the traditional model (TM), for which a single intestinal flow perfused the whole of the intestinal tissue. The segregated flow model (SFM) described a disproportionately greater extent of intestinal morphine glucuronidation for i.d. vs. i.v. administration. The present study applied the same PBPK modeling approaches to examine the contributions of the intestine and liver on the first-pass metabolism of the precursor, codeine (C, 3-methylmorphine) in the rat. Unexpectedly, the profiles of codeine, morphine and morphine-3β-glucuronide in whole blood, bile and urine, assayed by LCMS, were equally well described by both the TM-PBPK and SFM-PBPK. The fitted parameters for the models were similar, and the net formation intrinsic clearance of morphine (from codeine) for the liver was much higher, being 9- to 13-fold that of the intestine. Simulations, based on the absence of intestinal formation of morphine, correlated well with observations. The lack of discrimination of SFM and TM with the codeine data did not invalidate the SFM-PBPK model but rather suggests that the liver is the only major organ for codeine metabolism. Because of little or no contribution by the intestine to the metabolism of codeine, both the TM- and SFM-PBPK models are equally consistent with the data. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Keumhan Noh
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Shu Chen
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada.,Apotex Inc., 150 Signet Drive, Toronto, Ontario, M9L 1T9, Canada
| | - Qi J Yang
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - K Sandy Pang
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
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Pang KS, Yang QJ, Noh K. Unequivocal evidence supporting the segregated flow intestinal model that discriminates intestine versus liver first-pass removal with PBPK modeling. Biopharm Drug Dispos 2016; 38:231-250. [PMID: 27977852 DOI: 10.1002/bdd.2056] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 12/01/2016] [Accepted: 12/01/2016] [Indexed: 11/08/2022]
Abstract
Merits of the segregated flow model (SFM), highlighting the intestine as inert serosa and active enterocyte regions, with a smaller fractional (fQ < 0.3) intestinal flow (QI ) perfusing the enterocyte region, are described. Less drug in the circulation reaches the enterocytes due to the lower flow (fQ QI ) in comparison with drug administered into the gut lumen, fostering the idea of route-dependent intestinal removal. The SFM has been found superior to the traditional model (TM), which views the serosa and enterocytes totally as a well-mixed tissue perfused by 100% of the intestinal flow, QI . The SFM model is able to explain the lower extents of intestinal metabolism of enalapril, morphine and midazolam with i.v. vs. p.o. dosing. For morphine, the urine/bile ratio of the metabolite, morphine glucuronide MGurineMGbile for p.o. was 2.6× that of i.v. This was due to the higher proportion of intestinally formed morphine glucuronide, appearing more in urine than in bile due to its low permeability and greater extent of intestinal formation with p.o. administration. By contrast, the TM predicted the same MGurineMGbile for p.o. vs. i.v. The TM predicted that the contributions of the intestine:liver to first-pass removal were 46%:54% for both p.o. and i.v. The SFM predicted same 46%:54% (intestine:liver) for p.o., but 9%:91% for i.v. By contrast, the kinetics of codeine, the precursor of morphine, was described equally well by the SFM- and TM-PBPK models, a trend suggesting that intestinal metabolism of codeine is negligible. Fits to these PBPK models further provide insightful information towards metabolite formation: available fractions and the fractions of hepatic and total clearances that form the metabolite in question. The SFM-PBPK model is useful to identify not only the presence of intestinal metabolism but the contributions of the intestine and liver for metabolite formation. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- K Sandy Pang
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Qi Joy Yang
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Keumhan Noh
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
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Ge S, Tu Y, Hu M. Challenges and Opportunities with Predicting in Vivo Phase II Metabolism via Glucuronidation from in Vitro Data. ACTA ACUST UNITED AC 2016; 2:326-338. [PMID: 28966903 DOI: 10.1007/s40495-016-0076-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Glucuronidation is the most important phase II metabolic pathway which is responsible for the clearance of many endogenous and exogenous compounds. To better understand the elimination process for compounds undergoing glucuronidation and identify compounds with desirable in vivo pharmacokinetic properties, many efforts have been made to predict in vivo glucuronidation using in vitro data. In this article, we reviewed typical approaches used in previous predictions. The problems and challenges in prediction of glucuronidation were discussed. Besides that different incubation conditions can affect the prediction accuracy, other factors including efflux / uptake transporters, enterohepatic recycling, and deglucuronidation reactions also contribute to the disposition of glucuronides and make the prediction more difficult. PBPK modeling, which can describe more complicated process in vivo, is a promising prediction strategy which may greatly improve the prediction of glucuronidation and potential DDIs involving glucuronidation. Based on previous studies, we proposed a transport-glucuronidation classification system, which was built based on the kinetics of both glucuronidation and transport of the glucuronide. This system could be a very useful tool to achieve better in vivo predictions.
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Affiliation(s)
- Shufan Ge
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, The University of Houston, 1441 Moursund Street, Houston, TX, 77030, USA
| | - Yifan Tu
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, The University of Houston, 1441 Moursund Street, Houston, TX, 77030, USA
| | - Ming Hu
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, The University of Houston, 1441 Moursund Street, Houston, TX, 77030, USA
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Kulkarni P, Korzekwa K, Nagar S. Intracellular Unbound Atorvastatin Concentrations in the Presence of Metabolism and Transport. J Pharmacol Exp Ther 2016; 359:26-36. [PMID: 27451408 DOI: 10.1124/jpet.116.235689] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 07/20/2016] [Indexed: 12/26/2022] Open
Abstract
Accurate prediction of drug target activity and rational dosing regimen design require knowledge of drug concentrations at the target. It is important to understand the impact of processes such as membrane permeability, partitioning, and active transport on intracellular drug concentrations. The present study aimed to predict intracellular unbound atorvastatin concentrations and characterize the effect of enzyme-transporter interplay on these concentrations. Single-pass liver perfusion studies were conducted in rats using atorvastatin (ATV, 1 µM) alone at 4°C and at 37°C in presence of rifampin (RIF, 20 µM) and 1-aminobenzotriazole (ABT, 1 mM), separately and in combination. The unbound intracellular ATV concentration was predicted with a five-compartment explicit membrane model using the parameterized diffusional influx clearance, active basolateral uptake clearance, and metabolic clearance. Chemical inhibition of uptake and metabolism at 37°C proved to be better controls relative to studies at 4°C. The predicted unbound intracellular concentration at the end of the 50-minute perfusion in the +ABT , +ABT+RIF, and the ATV-only groups was 6.5 µM, 0.58 µM, and 5.14 µM, respectively. The predicted total liver concentrations and amount recovered in bile were within 0.94-1.3 fold of the observed value in all groups. The fold difference in total liver concentration did not always extrapolate to the fold difference in predicted unbound concentration across groups. Together, these results support the use of compartmental modeling to predict intracellular concentrations in dynamic organ-based systems. These predictions can provide insight into the role of uptake transporters and metabolizing enzymes in determining drug tissue concentrations.
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Affiliation(s)
- Priyanka Kulkarni
- Department of Pharmaceutical Sciences, Temple University School of Pharmacy, Philadelphia, Pennsylvania
| | - Kenneth Korzekwa
- Department of Pharmaceutical Sciences, Temple University School of Pharmacy, Philadelphia, Pennsylvania
| | - Swati Nagar
- Department of Pharmaceutical Sciences, Temple University School of Pharmacy, Philadelphia, Pennsylvania
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