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Bržezická T, Mlčochová H, Glatz Z, Kohútová L. Contactless conductivity detector as a tool for improving universality and sensitivity of capillary electrophoresis-frontal analysis: Proof of concept. J Sep Sci 2024; 47:e2300667. [PMID: 38234025 DOI: 10.1002/jssc.202300667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 11/13/2023] [Accepted: 12/05/2023] [Indexed: 01/19/2024]
Abstract
Drug binding to plasma proteins influences processes such as liberation, adsorption, disposition, metabolism, and elimination of drugs, which are thus one of the key steps of a new drug development. As a result, the characterization of drug-protein interactions is an essential part of these time- and money-consuming processes. It is important to determine not only the binding strength and the stoichiometry of interaction, but also the binding site of a drug on a protein molecule, because two drugs with the same binding site can mutually affect free drug concentration. Capillary electrophoresis-frontal analysis with mobility shift affinity capillary electrophoresis is one of the most used affinity capillary electrophoresis methods for the characterization of these interactions. In this study, a well-known sensitivity problem of most capillary electrophoresis-frontal analyses using ultraviolet detection is solved by its combination with contactless conductivity detection, which provided sixfold lower limits of quantitation and detection. Binding parameters of the human serum albumin-salicylic acid model affinity pair were evaluated by this newly developed approach and by the classical approach with ultraviolet detection primarily used for their mutual comparison. The results of both approaches agreed well and are also in agreement with literature data obtained using different techniques.
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Affiliation(s)
- Taťána Bržezická
- Department of Biochemistry, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Hana Mlčochová
- Department of Biochemistry, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Zdeněk Glatz
- Department of Biochemistry, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Lenka Kohútová
- Department of Biochemistry, Faculty of Science, Masaryk University, Brno, Czech Republic
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Yang C, Xue M, He Y, Yin H, Yang C, Zhong D, Zeng H, Zheng Y, Diao X. Absorption, Distribution, Metabolism, and Excretion of [ 14C]BS1801, a Selenium-Containing Drug Candidate, in Rats. Molecules 2023; 28:8102. [PMID: 38138590 PMCID: PMC10745422 DOI: 10.3390/molecules28248102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 12/09/2023] [Accepted: 12/12/2023] [Indexed: 12/24/2023] Open
Abstract
BS1801 is a selenium-containing drug candidate with potential for treating liver and lung fibrosis. To fully elucidate the biotransformation of BS1801 in animals and provide sufficient preclinical drug metabolism data for human mass balance study, the metabolism of BS1801 in rats was investigated. We used radiolabeling techniques to investigate the mass balance, tissue distribution, and metabolite identification of BS1801 in Sprague-Dawley/Long-Evans rats after a single oral dose of 100 mg/kg (100 μCi/kg) [14C]BS1801: 1. The mean recovery of radioactive substances in urine and feces was 93.39% within 168 h postdose, and feces were the main excretion route. 2. Additionally, less than 1.00% of the dose was recovered from either urine or bile. 3. BS1801-related components were widely distributed throughout the body. 4. Fifteen metabolites were identified in rat plasma, urine, feces, and bile, and BS1801 was detected only in feces. 5. BS1801-M484, the methylation product obtained via a N-Se bond reduction in BS1801, was the most abundant drug-related component in plasma. The main metabolic pathways of BS1801 were reduction, amide hydrolysis, oxidation, and methylation. Overall, BS1801 was distributed throughout the body, and excreted mainly as an intact BS1801 form through feces. No differences were observed between male and female rats in distribution, metabolism, and excretion of BS1801.
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Affiliation(s)
- Cheng Yang
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing 210023, China;
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201210, China; (Y.H.); (C.Y.); (D.Z.)
| | - Mingzhen Xue
- Jiangsu Key Laboratory for Functional Substances of Chinese Medicine, Nanjing University of Chinese Medicine, Nanjing 210023, China;
| | - Yifei He
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201210, China; (Y.H.); (C.Y.); (D.Z.)
| | - Hanwei Yin
- Shanghai Yuanxi Pharmaceutical Technology Co., Ltd., Shanghai 201203, China;
| | - Chen Yang
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201210, China; (Y.H.); (C.Y.); (D.Z.)
| | - Dafang Zhong
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201210, China; (Y.H.); (C.Y.); (D.Z.)
| | - Huihui Zeng
- Shanghai Yuanxi Pharmaceutical Technology Co., Ltd., Shanghai 201203, China;
| | - Yuandong Zheng
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201210, China; (Y.H.); (C.Y.); (D.Z.)
| | - Xingxing Diao
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing 210023, China;
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201210, China; (Y.H.); (C.Y.); (D.Z.)
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Abstract
According to the free drug hypothesis (FDH), only free, unbound drug is available to interact with biological targets. This hypothesis is the fundamental principle that continues to explain the vast majority of all pharmacokinetic and pharmacodynamic processes. Under the FDH, the free drug concentration at the target site is considered the driver of pharmacodynamic activity and pharmacokinetic processes. However, deviations from the FDH are observed in hepatic uptake and clearance predictions, where observed unbound intrinsic hepatic clearance (CLint,u) is larger than expected. Such deviations are commonly observed when plasma proteins are present and form the basis of the so-called plasma protein-mediated uptake effect (PMUE). This review will discuss the basis of plasma protein binding as it pertains to hepatic clearance based on the FDH, as well as several hypotheses that may explain the underlying mechanisms of PMUE. Notably, some, but not all, potential mechanisms remained aligned with the FDH. Finally, we will outline possible experimental strategies to elucidate PMUE mechanisms. Understanding the mechanisms of PMUE and its potential contribution to clearance underprediction is vital to improving the drug development process.
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Eneberg E, Jones C, Jensen T, Langthaler K, Bundgaard C. Practical Application of Rodent Transporter Knockout Models to assess Brain Penetration in Drug Discovery. Drug Metab Lett 2022; 15:12-21. [PMID: 35196975 DOI: 10.2174/1872312815666220222091032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 12/02/2021] [Accepted: 01/03/2022] [Indexed: 11/22/2022]
Abstract
BACKGROUND & OBJECTIVE Compound X is a drug candidate for the treatment of neurodegenerative diseases. Its brain distribution was evaluated as part of the lead identification and optimization of early drug discovery. METHODS The brain distribution of compound X was studied in genetic transporter knockout rodent models, in vivo models with a chemical inhibitor and in vitro transporter cell systems. RESULTS Compound X was found to be a substrate for human Breast Cancer-Resistance Protein (BCRP) in vitro (efflux ratio 8.1) and rodent Bcrp in vivo (Kp,uuKO/Kp,uuWT = 0.15/0.057 = 2.7, p < 0.05) but not a substrate for human P-glycoprotein (P-gp) in vitro (efflux ratio 1.0) nor rodent P-gp in vivo (Kp,uuKO/Kp,uuWT = 0.056/0.051 = 1.1, p > 0.05). When both transporters were knocked out in vivo, Kp,uu increased to 0.51 ± 0.02. Similar patterns observed across compounds with related chemistry corroborated structure-activity relationship. CONCLUSION While in vitro assays showed compound X to be a substrate for human BCRP and not P-gp, in vivo studies indicated a synergistic effect between rodent efflux transporters. However, this only accounted for ~50% of restricted BBB-transport, suggesting involvement from other efflux transporters. Given Kp,uu is a key criterion for assessing technical quality of CNS candidates before progression into clinical development, it is important to identify relevant screening assays for a better understanding of low Kp,uu and brain distribution in pre-clinical models for translation to humans.
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Affiliation(s)
- Elin Eneberg
- Translational DMPK, H. Lundbeck A/S, Valby, 2500 Copenhagen, Denmark
| | - Christopher Jones
- Translational DMPK, H. Lundbeck A/S, Valby, 2500 Copenhagen, Denmark
| | - Thomas Jensen
- Medicinal Chemistry, H. Lundbeck A/S, Valby, 2500 Copenhagen, Denmark
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Patel NC, Feng B, Hou X, West MA, Trapa PE, Sciabola S, Verhoest P, Liras JL, Maurer TS, Wager TT. Harnessing Preclinical Data as a Predictive Tool for Human Brain Tissue Targeting. ACS Chem Neurosci 2021; 12:1007-1017. [PMID: 33651587 DOI: 10.1021/acschemneuro.0c00807] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
One of the objectives within the medicinal chemistry discipline is to design tissue targeting molecules. The objective of tissue specificity can be either to gain drug access to the compartment of interest (e.g., the CNS) for Neuroscience targets or to restrict drug access to the CNS for all other therapeutic areas. Both neuroscience and non-neuroscience therapeutic areas have struggled to quantitatively estimate brain penetration or the lack thereof with compounds that are substrates of efflux transport proteins such as P-glycoprotein (P-gp) and breast cancer resistant protein (BCRP) that are key components of the blood-brain barrier (BBB). It has been well established that drug candidates with high efflux ratios (ER) of these transporters have poor penetration into brain tissue. In the current work, we outline a parallel analysis to previously published models for the prediction of brain penetration that utilize an alternate MDR1-MDCK cell line as a better predictor of brain penetration and whether a correlation between in vitro, rodent data, non-human primate (NHP), and human in vivo brain penetration data could be established. Analysis of structural and physicochemical properties in conjunction with in vitro parameters and preclinical in vivo data has been highlighted in this manuscript as a continuation of the previously published work.
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Affiliation(s)
- Nandini C. Patel
- Medicine Design, Medicinal Chemistry, Pfizer Worldwide R&D, 610 Main Street, Cambridge, Massachusetts 02139, United States
| | - Bo Feng
- Medicine Design, Pharmacokinetics, Dynamics, & Metabolism, Pfizer Worldwide R&D, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Xinjun Hou
- Medicine Design, Medicinal Chemistry, Pfizer Worldwide R&D, 610 Main Street, Cambridge, Massachusetts 02139, United States
| | - Mark A. West
- Medicine Design, Pharmacokinetics, Dynamics, & Metabolism, Pfizer Worldwide R&D, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Patrick E. Trapa
- Medicine Design, Pharmacokinetics, Dynamics, & Metabolism, Pfizer Worldwide R&D, 610 Main Street, Cambridge, Massachusetts 02139, United States
| | - Simone Sciabola
- Medicine Design, Medicinal Chemistry, Pfizer Worldwide R&D, 610 Main Street, Cambridge, Massachusetts 02139, United States
| | - Patrick Verhoest
- Medicine Design, Medicinal Chemistry, Pfizer Worldwide R&D, 610 Main Street, Cambridge, Massachusetts 02139, United States
| | - Jennifer L. Liras
- Medicine Design, Pharmacokinetics, Dynamics, & Metabolism, Pfizer Worldwide R&D, 610 Main Street, Cambridge, Massachusetts 02139, United States
| | - Tristan S. Maurer
- Medicine Design, Pharmacokinetics, Dynamics, & Metabolism, Pfizer Worldwide R&D, 610 Main Street, Cambridge, Massachusetts 02139, United States
| | - Travis T. Wager
- Medicine Design, Medicinal Chemistry, Pfizer Worldwide R&D, 610 Main Street, Cambridge, Massachusetts 02139, United States
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6
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Patel NC. Methods to optimize CNS exposure of drug candidates. Bioorg Med Chem Lett 2020; 30:127503. [DOI: 10.1016/j.bmcl.2020.127503] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 08/12/2020] [Accepted: 08/16/2020] [Indexed: 02/07/2023]
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7
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Wallenwein CM, Nova MV, Janas C, Jablonka L, Gao GF, Thurn M, Albrecht V, Wiehe A, Wacker MG. A dialysis-based in vitro drug release assay to study dynamics of the drug-protein transfer of temoporfin liposomes. Eur J Pharm Biopharm 2019; 143:44-50. [PMID: 31421208 DOI: 10.1016/j.ejpb.2019.08.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 08/14/2019] [Accepted: 08/14/2019] [Indexed: 12/11/2022]
Abstract
Today, a growing number of nanotherapeutics is utilized to deliver poorly soluble compounds using the intravenous route of administration. The drug release and the direct transfer of the active pharmaceutical ingredient to serum proteins plays an important role in bioavailability and accumulation of the drug at the target site. It is closely related to the formation of a protein corona as well as the plasma protein binding of the compound. In the present study, two in vitro drug release methods, the flow-through cell and the dispersion releaser technology, were evaluated with regards to their capability to measure a time-resolved profile of the serum protein binding. In this context, the photosensitizer temoporfin and temoporfin-loaded liposomes were tested. While in the fine capillaries of the flow-through cell a rapid agglomeration of proteins occurred, the dispersion releaser technology in combination with the four-step model enabled the measurement of the transfer of drugs from liposomes to proteins. In presence of 10% of fetal calf serum approximately 20% of the model compound temoporfin were bound to serum proteins within the first 3 h. At higher serum concentration this binding remained stable for approximately 10 h.
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Affiliation(s)
- Chantal M Wallenwein
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Branch for Translational Medicine and Pharmacology TMP, Theodor-Stern-Kai 7, 60596 Frankfurt (Main), Germany; Institute of Pharmaceutical Technology, Goethe University, Max-von-Laue-Str. 9, 60438 Frankfurt (Main), Germany
| | - Mônica Villa Nova
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Branch for Translational Medicine and Pharmacology TMP, Theodor-Stern-Kai 7, 60596 Frankfurt (Main), Germany; Institute of Pharmaceutical Technology, Goethe University, Max-von-Laue-Str. 9, 60438 Frankfurt (Main), Germany
| | - Christine Janas
- Institute of Pharmaceutical Technology, Goethe University, Max-von-Laue-Str. 9, 60438 Frankfurt (Main), Germany
| | - Laura Jablonka
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Branch for Translational Medicine and Pharmacology TMP, Theodor-Stern-Kai 7, 60596 Frankfurt (Main), Germany; Institute of Pharmaceutical Technology, Goethe University, Max-von-Laue-Str. 9, 60438 Frankfurt (Main), Germany
| | - Ge F Gao
- Institute of Pharmaceutical Technology, Goethe University, Max-von-Laue-Str. 9, 60438 Frankfurt (Main), Germany
| | - Manuela Thurn
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Branch for Translational Medicine and Pharmacology TMP, Theodor-Stern-Kai 7, 60596 Frankfurt (Main), Germany; Institute of Pharmaceutical Technology, Goethe University, Max-von-Laue-Str. 9, 60438 Frankfurt (Main), Germany
| | - Volker Albrecht
- Biolitec Research GmbH, Otto-Schott-Str. 15, 07745 Jena, Germany
| | - Arno Wiehe
- Biolitec Research GmbH, Otto-Schott-Str. 15, 07745 Jena, Germany
| | - Matthias G Wacker
- National University of Singapore, Department of Pharmacy, 6 Science Drive 2, Singapore 117546, Singapore.
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8
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Bhyrapuneni G, Thentu JB, Palacharla VRC, Muddana N, Aleti RR, Ajjala DR, Nirogi R. A definite measure of occupancy exposures, seeking with non-radiolabeled in vivo 5-HT2A receptor occupancy and in vitro free fractions. J Recept Signal Transduct Res 2018; 38:359-366. [PMID: 30481094 DOI: 10.1080/10799893.2018.1531888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Unbound drug concentration in the brain would be the true exposure responsible for specific target occupancy. Drug exposures from preclinical are total concentrations of those over/underestimate the clinical dose projection. With the application of mass spectrometry, the current work proposes a definite measure of test drug exposures at serotonin-2A occupancy. The 5-HT2A occupancy of antagonist in the rat brain has determined with non-radiolabeled tracer MDL-100,907 at an optimized dose (3 µg/kg) and treatment time (30 min). Equilibrium dialysis method determines the in vitro free fraction of the test antagonist in untreated rat brain homogenates and plasma. Drug-free fractions derived the unbound concentration (EC50) in plasma and brain at test doses. The corresponding binding affinities (Ki) correlated with the unbound concentrations. Except for quetiapine, the ED50 values in the dose-occupancy curves of antagonists are close and ranged from 1 to 3 mg/kg. The test drug quetiapine, eplivanserin, and clozapine showed high free fractions in plasma, but for ketanserin and olanzapine, the brain free fraction was higher. The correlation between the unbound EC50 of the antagonists and corresponding Ki values was good (r2=0.828). The improved EC50 accuracy with unbound concentrations was 10-250 folds in plasma and 10-170 folds in the brain. Further, the free fractions (fu, plasma/fu, brain) of test drugs had shown a correlation of ∼83% with brain permeability (Ctotal brain/Ctotal plasma), a limiting factor. Thus, correlating the occupancy with unbound exposure and pharmacology would result in an accurate measurement of drug potency and optimizes in selecting the clinical dose.
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Durk MR, Deshmukh G, Valle N, Ding X, Liederer BM, Liu X. Use of Subcutaneous and Intraperitoneal Administration Methods to Facilitate Cassette Dosing in Microdialysis Studies in Rats. Drug Metab Dispos 2018; 46:964-969. [PMID: 29700231 DOI: 10.1124/dmd.118.080697] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 04/24/2018] [Indexed: 01/14/2023] Open
Abstract
Microdialysis is a powerful technique allowing for real-time measurement of unbound drug concentrations in brain interstitial fluid in conscious animals. Use of microdialysis in drug discovery is limited by high resource requirement and low throughput, but this may be improved by cassette dosing. Administering multiple compounds intravenously of diverse physiochemical properties, it is often very challenging and time consuming to identify a vehicle that can dissolve all of the compounds. To overcome this limitation, the present study explores the possibility of administering a cassette dose of nine diverse compounds (carbamazepine, citalopram, desmethylclozapine, diphenhydramine, gabapentin, metoclopramide, naltrexone, quinidine, and risperidone) in suspension, rather than in solution, by intraperitoneal and subcutaneous routes, and determining if this is a viable option for assessing blood-brain barrier penetration in microdialysis studies. Repeated hourly subcutaneous dosing during the 6-hour microdialysis study allowed for the best attainment of distributional equilibrium between brain and plasma, resulting in less than a 2-fold difference in the unbound brain to unbound plasma concentration ratio for the cassette dosing method versus discrete dosing. Both subcutaneous and intraperitoneal repeated dosing can provide a more practical substitute for intravenous dosing in determining brain penetration of a cassette of diverse compounds in brain microdialysis studies. The results from the present study demonstrate that dosing compounds in suspension represents a practical approach to eliminating the technical challenge and labor-intensive step of preparation of solutions of a mixture of compounds and will enable the use of the cassette brain microdialysis method in a central nervous system drug discovery setting.
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Affiliation(s)
- Matthew R Durk
- Department of Drug Metabolism and Pharmacokinetics (M.R.D., G.D., X.D., B.M.L., X.L.) and IVS group (N.V.), Genentech Inc., South San Francisco, California
| | - Gauri Deshmukh
- Department of Drug Metabolism and Pharmacokinetics (M.R.D., G.D., X.D., B.M.L., X.L.) and IVS group (N.V.), Genentech Inc., South San Francisco, California
| | - Nicole Valle
- Department of Drug Metabolism and Pharmacokinetics (M.R.D., G.D., X.D., B.M.L., X.L.) and IVS group (N.V.), Genentech Inc., South San Francisco, California
| | - Xiao Ding
- Department of Drug Metabolism and Pharmacokinetics (M.R.D., G.D., X.D., B.M.L., X.L.) and IVS group (N.V.), Genentech Inc., South San Francisco, California
| | - Bianca M Liederer
- Department of Drug Metabolism and Pharmacokinetics (M.R.D., G.D., X.D., B.M.L., X.L.) and IVS group (N.V.), Genentech Inc., South San Francisco, California
| | - Xingrong Liu
- Department of Drug Metabolism and Pharmacokinetics (M.R.D., G.D., X.D., B.M.L., X.L.) and IVS group (N.V.), Genentech Inc., South San Francisco, California
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10
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Yahata M, Chiba K, Watanabe T, Sugiyama Y. Possibility of Predicting Serotonin Transporter Occupancy From the In Vitro Inhibition Constant for Serotonin Transporter, the Clinically Relevant Plasma Concentration of Unbound Drugs, and Their Profiles for Substrates of Transporters. J Pharm Sci 2017; 106:2345-2356. [PMID: 28501470 DOI: 10.1016/j.xphs.2017.05.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 04/20/2017] [Accepted: 05/02/2017] [Indexed: 01/16/2023]
Abstract
Accurate prediction of target occupancy facilitates central nervous system drug development. In this review, we discuss the predictability of serotonin transporter (SERT) occupancy in human brain estimated from in vitro Ki values for human SERT and plasma concentrations of unbound drug (Cu,plasma), as well as the impact of drug transporters in the blood-brain barrier. First, the geometric means of in vitro Ki values were compared with the means of in vivo Ki values (Ki,u,plasma) which were calculated as Cu,plasma values at 50% occupancy of SERT obtained from previous clinical positron emission tomography/single photon emission computed tomography imaging studies for 6 selective serotonin transporter reuptake inhibitors and 3 serotonin norepinephrine reuptake inhibitors. The in vitro Ki values for 7 drugs were comparable to their in vivo Ki,u,plasma values within 3-fold difference. SERT occupancy was overestimated for 5 drugs (P-glycoprotein substrates) and underestimated for 2 drugs (presumably uptake transporter substrates, although no evidence exists as yet). In conclusion, prediction of human SERT occupancy from in vitro Ki values and Cu,plasma was successful for drugs that are not transporter substrates and will become possible in future even for transporter substrates, once the transporter activities will be accurately estimated from in vitro experiments.
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Affiliation(s)
- Masahiro Yahata
- Preclinical Research Laboratories, Sumitomo Dainippon Pharma Company, Ltd., Osaka, Japan.
| | - Koji Chiba
- Laboratory of Clinical Pharmacology, Yokohama University of Pharmacy, Yokohama, Japan
| | - Takao Watanabe
- Preclinical Research Laboratories, Sumitomo Dainippon Pharma Company, Ltd., Osaka, Japan
| | - Yuichi Sugiyama
- Sugiyama Laboratory, RIKEN Innovation Center, Research Cluster for Innovation, RIKEN, Yokohama, Japan
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11
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Salphati L, Alicke B, Heffron TP, Shahidi-Latham S, Nishimura M, Cao T, Carano RA, Cheong J, Greve J, Koeppen H, Lau S, Lee LB, Nannini-Pepe M, Pang J, Plise EG, Quiason C, Rangell L, Zhang X, Gould SE, Phillips HS, Olivero AG. Brain Distribution and Efficacy of the Brain Penetrant PI3K Inhibitor GDC-0084 in Orthotopic Mouse Models of Human Glioblastoma. Drug Metab Dispos 2016; 44:1881-1889. [PMID: 27638506 DOI: 10.1124/dmd.116.071423] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 09/09/2016] [Indexed: 01/08/2023] Open
Abstract
Glioblastoma multiforme (GBM) is the most common primary brain tumor in adults. Limited treatment options have only marginally impacted patient survival over the past decades. The phophatidylinositol 3-kinase (PI3K) pathway, frequently altered in GBM, represents a potential target for the treatment of this glioma. 5-(6,6-Dimethyl-4-morpholino-8,9-dihydro-6H-[1,4]oxazino[4,3-e]purin-2-yl)pyrimidin-2-amine (GDC-0084) is a PI3K inhibitor that was specifically optimized to cross the blood-brain barrier. The goals of our studies were to characterize the brain distribution, pharmacodynamic (PD) effect, and efficacy of GDC-0084 in orthotopic xenograft models of GBM. GDC-0084 was tested in vitro to assess its sensitivity to the efflux transporters P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) and in vivo in mice to evaluate its effects on the PI3K pathway in intact brain. Mice bearing U87 or GS2 intracranial tumors were treated with GDC-0084 to assess its brain distribution by matrix-assisted laser desorption ionization (MALDI) imaging and measure its PD effects and efficacy in GBM orthotopic models. Studies in transfected cells indicated that GDC-0084 was not a substrate of P-gp or BCRP. GDC-0084 markedly inhibited the PI3K pathway in mouse brain, causing up to 90% suppression of the pAkt signal. MALDI imaging showed GDC-0084 distributed evenly in brain and intracranial U87 and GS2 tumors. GDC-0084 achieved significant tumor growth inhibition of 70% and 40% against the U87 and GS2 orthotopic models, respectively. GDC-0084 distribution throughout the brain and intracranial tumors led to potent inhibition of the PI3K pathway. Its efficacy in orthotopic models of GBM suggests that it could be effective in the treatment of GBM. GDC-0084 is currently in phase I clinical trials.
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Affiliation(s)
- Laurent Salphati
- Departments of Drug Metabolism and Pharmacokinetics (L.S., S.S.-L., J.C., J.P., E.G.P., C.Q., X.Z.), Discovery Chemistry (T.P.H., A.G.O.), Cancer Signaling and Translational Oncology (B.A., M.N., M.N.-P., L.B.L., S.E.G., H.S.P.), Biomedical Imaging (T.C., R.A.C., J.G.), and Pathology (H.K., S.L., L.R.), Genentech Inc., South San Francisco, California
| | - Bruno Alicke
- Departments of Drug Metabolism and Pharmacokinetics (L.S., S.S.-L., J.C., J.P., E.G.P., C.Q., X.Z.), Discovery Chemistry (T.P.H., A.G.O.), Cancer Signaling and Translational Oncology (B.A., M.N., M.N.-P., L.B.L., S.E.G., H.S.P.), Biomedical Imaging (T.C., R.A.C., J.G.), and Pathology (H.K., S.L., L.R.), Genentech Inc., South San Francisco, California
| | - Timothy P Heffron
- Departments of Drug Metabolism and Pharmacokinetics (L.S., S.S.-L., J.C., J.P., E.G.P., C.Q., X.Z.), Discovery Chemistry (T.P.H., A.G.O.), Cancer Signaling and Translational Oncology (B.A., M.N., M.N.-P., L.B.L., S.E.G., H.S.P.), Biomedical Imaging (T.C., R.A.C., J.G.), and Pathology (H.K., S.L., L.R.), Genentech Inc., South San Francisco, California
| | - Sheerin Shahidi-Latham
- Departments of Drug Metabolism and Pharmacokinetics (L.S., S.S.-L., J.C., J.P., E.G.P., C.Q., X.Z.), Discovery Chemistry (T.P.H., A.G.O.), Cancer Signaling and Translational Oncology (B.A., M.N., M.N.-P., L.B.L., S.E.G., H.S.P.), Biomedical Imaging (T.C., R.A.C., J.G.), and Pathology (H.K., S.L., L.R.), Genentech Inc., South San Francisco, California
| | - Merry Nishimura
- Departments of Drug Metabolism and Pharmacokinetics (L.S., S.S.-L., J.C., J.P., E.G.P., C.Q., X.Z.), Discovery Chemistry (T.P.H., A.G.O.), Cancer Signaling and Translational Oncology (B.A., M.N., M.N.-P., L.B.L., S.E.G., H.S.P.), Biomedical Imaging (T.C., R.A.C., J.G.), and Pathology (H.K., S.L., L.R.), Genentech Inc., South San Francisco, California
| | - Tim Cao
- Departments of Drug Metabolism and Pharmacokinetics (L.S., S.S.-L., J.C., J.P., E.G.P., C.Q., X.Z.), Discovery Chemistry (T.P.H., A.G.O.), Cancer Signaling and Translational Oncology (B.A., M.N., M.N.-P., L.B.L., S.E.G., H.S.P.), Biomedical Imaging (T.C., R.A.C., J.G.), and Pathology (H.K., S.L., L.R.), Genentech Inc., South San Francisco, California
| | - Richard A Carano
- Departments of Drug Metabolism and Pharmacokinetics (L.S., S.S.-L., J.C., J.P., E.G.P., C.Q., X.Z.), Discovery Chemistry (T.P.H., A.G.O.), Cancer Signaling and Translational Oncology (B.A., M.N., M.N.-P., L.B.L., S.E.G., H.S.P.), Biomedical Imaging (T.C., R.A.C., J.G.), and Pathology (H.K., S.L., L.R.), Genentech Inc., South San Francisco, California
| | - Jonathan Cheong
- Departments of Drug Metabolism and Pharmacokinetics (L.S., S.S.-L., J.C., J.P., E.G.P., C.Q., X.Z.), Discovery Chemistry (T.P.H., A.G.O.), Cancer Signaling and Translational Oncology (B.A., M.N., M.N.-P., L.B.L., S.E.G., H.S.P.), Biomedical Imaging (T.C., R.A.C., J.G.), and Pathology (H.K., S.L., L.R.), Genentech Inc., South San Francisco, California
| | - Joan Greve
- Departments of Drug Metabolism and Pharmacokinetics (L.S., S.S.-L., J.C., J.P., E.G.P., C.Q., X.Z.), Discovery Chemistry (T.P.H., A.G.O.), Cancer Signaling and Translational Oncology (B.A., M.N., M.N.-P., L.B.L., S.E.G., H.S.P.), Biomedical Imaging (T.C., R.A.C., J.G.), and Pathology (H.K., S.L., L.R.), Genentech Inc., South San Francisco, California
| | - Hartmut Koeppen
- Departments of Drug Metabolism and Pharmacokinetics (L.S., S.S.-L., J.C., J.P., E.G.P., C.Q., X.Z.), Discovery Chemistry (T.P.H., A.G.O.), Cancer Signaling and Translational Oncology (B.A., M.N., M.N.-P., L.B.L., S.E.G., H.S.P.), Biomedical Imaging (T.C., R.A.C., J.G.), and Pathology (H.K., S.L., L.R.), Genentech Inc., South San Francisco, California
| | - Shari Lau
- Departments of Drug Metabolism and Pharmacokinetics (L.S., S.S.-L., J.C., J.P., E.G.P., C.Q., X.Z.), Discovery Chemistry (T.P.H., A.G.O.), Cancer Signaling and Translational Oncology (B.A., M.N., M.N.-P., L.B.L., S.E.G., H.S.P.), Biomedical Imaging (T.C., R.A.C., J.G.), and Pathology (H.K., S.L., L.R.), Genentech Inc., South San Francisco, California
| | - Leslie B Lee
- Departments of Drug Metabolism and Pharmacokinetics (L.S., S.S.-L., J.C., J.P., E.G.P., C.Q., X.Z.), Discovery Chemistry (T.P.H., A.G.O.), Cancer Signaling and Translational Oncology (B.A., M.N., M.N.-P., L.B.L., S.E.G., H.S.P.), Biomedical Imaging (T.C., R.A.C., J.G.), and Pathology (H.K., S.L., L.R.), Genentech Inc., South San Francisco, California
| | - Michelle Nannini-Pepe
- Departments of Drug Metabolism and Pharmacokinetics (L.S., S.S.-L., J.C., J.P., E.G.P., C.Q., X.Z.), Discovery Chemistry (T.P.H., A.G.O.), Cancer Signaling and Translational Oncology (B.A., M.N., M.N.-P., L.B.L., S.E.G., H.S.P.), Biomedical Imaging (T.C., R.A.C., J.G.), and Pathology (H.K., S.L., L.R.), Genentech Inc., South San Francisco, California
| | - Jodie Pang
- Departments of Drug Metabolism and Pharmacokinetics (L.S., S.S.-L., J.C., J.P., E.G.P., C.Q., X.Z.), Discovery Chemistry (T.P.H., A.G.O.), Cancer Signaling and Translational Oncology (B.A., M.N., M.N.-P., L.B.L., S.E.G., H.S.P.), Biomedical Imaging (T.C., R.A.C., J.G.), and Pathology (H.K., S.L., L.R.), Genentech Inc., South San Francisco, California
| | - Emile G Plise
- Departments of Drug Metabolism and Pharmacokinetics (L.S., S.S.-L., J.C., J.P., E.G.P., C.Q., X.Z.), Discovery Chemistry (T.P.H., A.G.O.), Cancer Signaling and Translational Oncology (B.A., M.N., M.N.-P., L.B.L., S.E.G., H.S.P.), Biomedical Imaging (T.C., R.A.C., J.G.), and Pathology (H.K., S.L., L.R.), Genentech Inc., South San Francisco, California
| | - Cristine Quiason
- Departments of Drug Metabolism and Pharmacokinetics (L.S., S.S.-L., J.C., J.P., E.G.P., C.Q., X.Z.), Discovery Chemistry (T.P.H., A.G.O.), Cancer Signaling and Translational Oncology (B.A., M.N., M.N.-P., L.B.L., S.E.G., H.S.P.), Biomedical Imaging (T.C., R.A.C., J.G.), and Pathology (H.K., S.L., L.R.), Genentech Inc., South San Francisco, California
| | - Linda Rangell
- Departments of Drug Metabolism and Pharmacokinetics (L.S., S.S.-L., J.C., J.P., E.G.P., C.Q., X.Z.), Discovery Chemistry (T.P.H., A.G.O.), Cancer Signaling and Translational Oncology (B.A., M.N., M.N.-P., L.B.L., S.E.G., H.S.P.), Biomedical Imaging (T.C., R.A.C., J.G.), and Pathology (H.K., S.L., L.R.), Genentech Inc., South San Francisco, California
| | - Xiaolin Zhang
- Departments of Drug Metabolism and Pharmacokinetics (L.S., S.S.-L., J.C., J.P., E.G.P., C.Q., X.Z.), Discovery Chemistry (T.P.H., A.G.O.), Cancer Signaling and Translational Oncology (B.A., M.N., M.N.-P., L.B.L., S.E.G., H.S.P.), Biomedical Imaging (T.C., R.A.C., J.G.), and Pathology (H.K., S.L., L.R.), Genentech Inc., South San Francisco, California
| | - Stephen E Gould
- Departments of Drug Metabolism and Pharmacokinetics (L.S., S.S.-L., J.C., J.P., E.G.P., C.Q., X.Z.), Discovery Chemistry (T.P.H., A.G.O.), Cancer Signaling and Translational Oncology (B.A., M.N., M.N.-P., L.B.L., S.E.G., H.S.P.), Biomedical Imaging (T.C., R.A.C., J.G.), and Pathology (H.K., S.L., L.R.), Genentech Inc., South San Francisco, California
| | - Heidi S Phillips
- Departments of Drug Metabolism and Pharmacokinetics (L.S., S.S.-L., J.C., J.P., E.G.P., C.Q., X.Z.), Discovery Chemistry (T.P.H., A.G.O.), Cancer Signaling and Translational Oncology (B.A., M.N., M.N.-P., L.B.L., S.E.G., H.S.P.), Biomedical Imaging (T.C., R.A.C., J.G.), and Pathology (H.K., S.L., L.R.), Genentech Inc., South San Francisco, California
| | - Alan G Olivero
- Departments of Drug Metabolism and Pharmacokinetics (L.S., S.S.-L., J.C., J.P., E.G.P., C.Q., X.Z.), Discovery Chemistry (T.P.H., A.G.O.), Cancer Signaling and Translational Oncology (B.A., M.N., M.N.-P., L.B.L., S.E.G., H.S.P.), Biomedical Imaging (T.C., R.A.C., J.G.), and Pathology (H.K., S.L., L.R.), Genentech Inc., South San Francisco, California
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Sawant-Basak A, Chen L, Shaffer CL, Palumbo D, Schmidt A, Tseng E, Spracklin DK, Gallezot JD, Labaree D, Nabulsi N, Huang Y, Carson RE, McCarthy T. Quantitative projection of human brain penetration of the H3 antagonist PF-03654746 by integrating rat-derived brain partitioning and PET receptor occupancy. Xenobiotica 2016; 47:119-126. [DOI: 10.3109/00498254.2016.1166531] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Aarti Sawant-Basak
- Departments of Pharmacokinetics, Dynamics, and Metabolism, Pfizer Inc., Cambridge, MA, USA,
| | - Laigao Chen
- Clinical & Translational Imaging, Pfizer Inc., Cambridge, MA, USA,
| | | | - Donna Palumbo
- Worldwide Research and Development, Pfizer Inc., Cambridge, MA, USA, and
| | - Anne Schmidt
- Departments of Pharmacokinetics, Dynamics, and Metabolism, Pfizer Inc., Cambridge, MA, USA,
| | - Elaine Tseng
- Departments of Pharmacokinetics, Dynamics, and Metabolism, Pfizer Inc., Cambridge, MA, USA,
| | - Douglas K. Spracklin
- Departments of Pharmacokinetics, Dynamics, and Metabolism, Pfizer Inc., Cambridge, MA, USA,
| | | | - David Labaree
- Department of Diagnostic Radiology, Yale University, New Haven, CT, USA
| | - Nabeel Nabulsi
- Department of Diagnostic Radiology, Yale University, New Haven, CT, USA
| | - Yiyun Huang
- Department of Diagnostic Radiology, Yale University, New Haven, CT, USA
| | - Richard E. Carson
- Department of Diagnostic Radiology, Yale University, New Haven, CT, USA
| | - Timothy McCarthy
- Clinical & Translational Imaging, Pfizer Inc., Cambridge, MA, USA,
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13
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Modi ME, Majchrzak MJ, Fonseca KR, Doran A, Osgood S, Vanase-Frawley M, Feyfant E, McInnes H, Darvari R, Buhl DL, Kablaoui NM. Peripheral Administration of a Long-Acting Peptide Oxytocin Receptor Agonist Inhibits Fear-Induced Freezing. J Pharmacol Exp Ther 2016; 358:164-72. [PMID: 27217590 PMCID: PMC4959095 DOI: 10.1124/jpet.116.232702] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 05/11/2016] [Indexed: 01/05/2023] Open
Abstract
Oxytocin (OT) modulates the expression of social and emotional behaviors and consequently has been proposed as a pharmacologic treatment of psychiatric diseases, including autism spectrum disorders and schizophrenia; however, endogenous OT has a short half-life in plasma and poor permeability across the blood-brain barrier. Recent efforts have focused on the development of novel drug delivery methods to enhance brain penetration, but few efforts have aimed at improving its half-life. To explore the behavioral efficacy of an OT analog with enhanced plasma stability, we developed PF-06655075 (PF1), a novel non–brain-penetrant OT receptor agonist with increased selectivity for the OT receptor and significantly increased pharmacokinetic stability. PF-06478939 was generated with only increased stability to disambiguate changes to selectivity versus stability. The efficacy of these compounds in evoking behavioral effects was tested in a conditioned fear paradigm. Both central and peripheral administration of PF1 inhibited freezing in response to a conditioned fear stimulus. Peripheral administration of PF1 resulted in a sustained level of plasma concentrations for greater than 20 hours but no detectable accumulation in brain tissue, suggesting that plasma or cerebrospinal fluid exposure was sufficient to evoke behavioral effects. Behavioral efficacy of peripherally administered OT receptor agonists on conditioned fear response opens the door to potential peripheral mechanisms in other behavioral paradigms, whether they are mediated by direct peripheral activation or feed-forward responses. Compound PF1 is freely available as a tool compound to further explore the role of peripheral OT in behavioral response.
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Affiliation(s)
- Meera E Modi
- Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.)
| | - Mark J Majchrzak
- Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.)
| | - Kari R Fonseca
- Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.)
| | - Angela Doran
- Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.)
| | - Sarah Osgood
- Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.)
| | - Michelle Vanase-Frawley
- Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.)
| | - Eric Feyfant
- Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.)
| | - Heather McInnes
- Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.)
| | - Ramin Darvari
- Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.)
| | - Derek L Buhl
- Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.)
| | - Natasha M Kablaoui
- Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.)
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Gu Y, Wang J, Li K, Zhang L, Ren H, Guo L, Sai Y, Zhang W, Su W. Preclinical pharmacokinetics and disposition of a novel selective VEGFR inhibitor fruquintinib (HMPL-013) and the prediction of its human pharmacokinetics. Cancer Chemother Pharmacol 2014; 74:95-115. [PMID: 24817647 DOI: 10.1007/s00280-014-2471-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 04/22/2014] [Indexed: 01/07/2023]
Abstract
PURPOSE This study evaluated the preclinical pharmacokinetics (PK) and disposition of fruquintinib (HMPL-013), a small molecule vascular endothelial growth factor receptors inhibitor. METHODS In vitro and in vivo PK/ADME assays were conducted. Allometry and PK modeling/simulation were conducted to predict human PK parameters and the time course profiles. RESULTS HMPL-013 has high permeability without efflux. It shows moderate oral bioavailability of 42-53 % and Tmax < 4 h in mouse, rat, dog and monkey, with exposure-dose linearity proved in rats and dogs. No significant food effect is on dog PK. HMPL-013 has moderately high tissue distribution. It majorly distributes in gastrointestinal tract, liver, kidney, adrenal and adipose. The plasma protein binding fraction is 88-95 % in mouse, rat, dog and human, invariable up to 10 µM. The in vivo clearance of HMPL-013 is low, consistent with the in vitro scaling. Three major oxidative metabolites were identified in liver microsomes of mouse, rat, dog, monkey and human. Dog is mostly similar to human regarding in vitro metabolism. Demethylation, hydroxylation and sequential glucuronidation are the major in vivo metabolic reactions. Direct urinary and biliary excretion of HMPL-013 is negligible. Metabolizing to M1 (demethylation), sequentially glucuronidating, followed by biliary excretion, and to a less extent, by urinary excretion, are important elimination pathways for HMPL-013 in rats. HMPL-013 has low risk of drug-drug interaction. It is predicted to have favorable human PK properties and low efficacious dose. CONCLUSION HMPL-013 demonstrates good preclinical PK and enables successful human PK and dose projection. It is valuable for further clinical development.
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Patel NC, Schwarz J, Hou XJ, Hoover DJ, Xie L, Fliri AJ, Gallaschun RJ, Lazzaro JT, Bryce DK, Hoffmann WE, Hanks AN, McGinnis D, Marr ES, Gazard JL, Hajós M, Scialis RJ, Hurst RS, Shaffer CL, Pandit J, O’Donnell CJ. Discovery and Characterization of a Novel Dihydroisoxazole Class of α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) Receptor Potentiators. J Med Chem 2013; 56:9180-91. [DOI: 10.1021/jm401274b] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Nandini C. Patel
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Jacob Schwarz
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Xinjun J. Hou
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Dennis J. Hoover
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Longfei Xie
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Anton J. Fliri
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Randall J. Gallaschun
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - John T. Lazzaro
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Dianne K. Bryce
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - William E. Hoffmann
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Ashley N. Hanks
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Dina McGinnis
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Eric S. Marr
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Justin L. Gazard
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Mihály Hajós
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Renato J. Scialis
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Raymond S. Hurst
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Christopher L. Shaffer
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Jayvardhan Pandit
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Christopher J. O’Donnell
- Pfizer Worldwide Research and Development, Groton Laboratories, 445 Eastern Point Road, Groton, Connecticut 06340, United States
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Shaffer CL, Hurst RS, Scialis RJ, Osgood SM, Bryce DK, Hoffmann WE, Lazzaro JT, Hanks AN, Lotarski S, Weber ML, Liu J, Menniti FS, Schmidt CJ, Hajós M. Positive allosteric modulation of AMPA receptors from efficacy to toxicity: the interspecies exposure-response continuum of the novel potentiator PF-4778574. J Pharmacol Exp Ther 2013; 347:212-24. [PMID: 23899905 DOI: 10.1124/jpet.113.204735] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) positive allosteric modulation (i.e., "potentiation") has been proposed to overcome cognitive impairments in schizophrenia, but AMPAR overstimulation can be excitotoxic. Thus, it is critical to define carefully a potentiator's mechanism-based therapeutic index (TI) and to determine confidently its translatability from rodents to higher-order species. Accordingly, the novel AMPAR potentiator N-{(3R,4S)-3-[4-(5-cyano-2-thienyl)phenyl]tetrahydro-2H-pyran-4-yl}propane-2-sulfonamide (PF-4778574) was characterized in a series of in vitro assays and single-dose animal studies evaluating AMPAR-mediated activities related to cognition and safety to afford an unbound brain compound concentration (Cb,u)-normalized interspecies exposure-response relationship. Because it is unknown which AMPAR subtype(s) may be selectively potentiated for an optimal TI, PF-4778574 binding affinity and functional potency were determined in rodent tissues expected to express a native mixture of AMPAR subunits and their associated proteins to afford composite pharmacological values. Functional activity was also quantified in recombinant cell lines stably expressing human GluA2 flip or flop homotetramers. Procognitive effects of PF-4778574 were evaluated in both rat electrophysiological and nonhuman primate (nhp) behavioral models of pharmacologically induced N-methyl-d-aspartate receptor hypofunction. Safety studies assessed cerebellum-based AMPAR activation (mouse) and motor coordination disruptions (mouse, dog, and nhp), as well as convulsion (mouse, rat, and dog). The resulting empirically derived exposure-response continuum for PF-4778574 defines a single-dose-based TI of 8- to 16-fold for self-limiting tremor, a readily monitorable clinical adverse event. Importantly, the Cb,u mediating each physiological effect were highly consistent across species, with efficacy and convulsion occurring at just fractions of the in vitro-derived pharmacological values.
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Affiliation(s)
- Christopher L Shaffer
- Department of Pharmacokinetics, Pharmacodynamics and Metabolism (C.L.S., R.J.S., S.M.O., J.L.) and the Neuroscience Research Unit (R.S.H., D.K.B., W.E.H., J.T.L., A.N.H., S.L., M.L.W., F.S.M., C.J.S., M.H.), Worldwide Research and Development, Groton Laboratories, Pfizer Inc., Groton, Connecticut
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Weber ML, Hofland CM, Shaffer CL, Flik G, Cremers T, Hurst RS, Rollema H. Therapeutic doses of antidepressants are projected not to inhibit human α4β2 nicotinic acetylcholine receptors. Neuropharmacology 2013; 72:88-95. [PMID: 23639435 DOI: 10.1016/j.neuropharm.2013.04.027] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 03/20/2013] [Accepted: 04/10/2013] [Indexed: 11/22/2022]
Abstract
Inhibition of central α4β2 nAChRs by antidepressants, proposed to contribute to their clinical efficacy, was assessed for monoamine reuptake inhibitors (amitriptyline, nortriptyline, fluoxetine, sertraline, paroxetine, citalopram) by comparing projected human unbound brain drug concentrations (Cu,b) at therapeutic doses with concentrations that inhibit human α4β2 nAChRs in vitro. Inhibitory concentrations (IC50) were determined by patch clamp and ranged from 0.8-3.2 μM, except for nortriptyline (IC50 = 100 nM). Cu,b values were calculated from human unbound plasma drug concentrations (Cu,p) and rat-derived brain-to-plasma and extracellular fluid-to-plasma ratios for the unbound drug, which are near unity, due to much higher brain tissue binding than plasma protein binding of these drugs. Accordingly in humans, antidepressant Cu,b are projected to essentially equal Cu,p, with average values from 3-87 nM, which are 30-to-250-fold below their IC50 concentrations. Based on our model, monoaminergic antidepressants minimally inhibit central nAChRs and it is unlikely that α4β2 nAChR antagonism contributes to their antidepressant activity. Nortriptyline is an exception with a Cu,b that is 2-fold below its IC50, which is comparable to the nAChR antagonist (±)-mecamylamine, for which Cu,b is 4-fold below its IC50; both drugs will inhibit a substantial fraction of α4β2 nAChRs. The Cu,b of the α4β2 nAChR partial agonist varenicline, which has antidepressant-like activity in a murine model, is higher than its IC50 and varenicline is projected to cause ~70% inhibition of α4β2 nAChRs. Taken together these data may help explain the negative outcome of recent antidepressant augmentation trials with mecamylamine and the partial agonist CP-601927.
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Salphati L, Heffron TP, Alicke B, Nishimura M, Barck K, Carano RA, Cheong J, Edgar KA, Greve J, Kharbanda S, Koeppen H, Lau S, Lee LB, Pang J, Plise EG, Pokorny JL, Reslan HB, Sarkaria JN, Wallin JJ, Zhang X, Gould SE, Olivero AG, Phillips HS. Targeting the PI3K pathway in the brain--efficacy of a PI3K inhibitor optimized to cross the blood-brain barrier. Clin Cancer Res 2012; 18:6239-48. [PMID: 22992516 DOI: 10.1158/1078-0432.ccr-12-0720] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Glioblastoma (GBM), the most common primary brain tumor in adults, presents a high frequency of alteration in the PI3K pathway. Our objectives were to identify a dual PI3K/mTOR inhibitor optimized to cross the blood-brain barrier (BBB) and characterize its brain penetration, pathway modulation in the brain and efficacy in orthotopic xenograft models of GBM. EXPERIMENTAL DESIGN Physicochemical properties of PI3K inhibitors were optimized using in silico tools, leading to the identification of GNE-317. This compound was tested in cells overexpressing P-glycoprotein (P-gp) or breast cancer resistance protein (BCRP). Following administration to mice, GNE-317 plasma and brain concentrations were determined, and phosphorylated biomarkers (pAkt, p4EBP1, and pS6) were measured to assess PI3K pathway suppression in the brain. GNE-317 efficacy was evaluated in the U87, GS2, and GBM10 orthotopic models of GBM. RESULTS GNE-317 was identified as having physicochemical properties predictive of low efflux by P-gp and BCRP. Studies in transfected MDCK cells showed that GNE-317 was not a substrate of either transporter. GNE-317 markedly inhibited the PI3K pathway in mouse brain, causing 40% to 90% suppression of the pAkt and pS6 signals up to 6-hour postdose. GNE-317 was efficacious in the U87, GS2, and GBM10 orthotopic models, achieving tumor growth inhibition of 90% and 50%, and survival benefit, respectively. CONCLUSIONS These results indicated that specific optimization of PI3K inhibitors to cross the BBB led to potent suppression of the PI3K pathway in healthy brain. The efficacy of GNE-317 in 3 intracranial models of GBM suggested that this compound could be effective in the treatment of GBM.
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Affiliation(s)
- Laurent Salphati
- Department of Drug Metabolism and Pharmacokinetics, Genentech Inc, South San Francisco, California 94080, USA.
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Pellegatti M, Pagliarusco S, Solazzo L, Colato D. Plasma protein binding and blood-free concentrations: which studies are needed to develop a drug? Expert Opin Drug Metab Toxicol 2011; 7:1009-20. [DOI: 10.1517/17425255.2011.586336] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Petitjean O, Lu Q, Rouby J. Lack of lung tissue penetration after intravenous colistimethate administration: reply to Imberti. Intensive Care Med 2010; 36:1796-1797. [DOI: 10.1007/s00134-010-1961-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Abstract
IMPORTANCE OF THE FIELD The incorporation of brain tissue binding routinely in CNS drug discovery screening strategies has markedly changed the way CNS drug discovery is performed and is proving to be a valuable tool in identifying new therapies for CNS diseases. For many years emphasis has been placed on the magnitude of the brain to blood ratio, the bigger the better, even though, in many cases, brain total concentration (C(brain)) has no or, at best, poor correlation with receptor occupancy/pharmacodynamic readout. Today, C(brain) values measured during in vivo experiments are corrected for the fraction unbound measured through in vitro experiments using brain tissue homogenate or brain tissue slice to obtain an estimate of the brain unbound concentration (C(u,brain)), and this has been demonstrated across a range of CNS targets to give a much better correlation with receptor occupancy/pharmacodynamic readout. This apparently simple change in CNS lead optimisation strategy has de facto revolutionised the vision of the brain penetration concepts. AREAS COVERED IN THIS REVIEW This review will provide an overview of the use and applications of assessing brain free fraction to determine C(u,brain). TAKE HOME MESSAGE Assessing brain free fraction to determine C(u,brain) in CNS lead optimisation strategies is the surrogate of choice for rapidly assessing biophase concentration for the majority of CNS targets.
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Affiliation(s)
- Kevin D Read
- Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee, Scotland, UK.
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Shaffer CL. Defining Neuropharmacokinetic Parameters in CNS Drug Discovery to Determine Cross-Species Pharmacologic Exposure–Response Relationships. Annual Reports in Medicinal Chemistry 2010. [DOI: 10.1016/s0065-7743(10)45004-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Nguyen TB, Kumar EVKS, Sil D, Wood SJ, Miller KA, Warshakoon HJ, Datta A, David SA. Controlling plasma protein binding: structural correlates of interactions of hydrophobic polyamine endotoxin sequestrants with human serum albumin. Mol Pharm 2009; 5:1131-7. [PMID: 19434925 DOI: 10.1021/mp8001123] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Hydrophobically substituted polyamine compounds, particularly N-acyl or N-alkyl derivatives of homospermine, are potent endotoxin (lipopolysaccharide) sequestrants. Despite their polycationic nature, the aqueous solubilites are limited owing to the considerable overall hydrophobicity contributed by the long-chain aliphatic substituent, but solubilization is readily achieved in the presence of human serum albumin (HSA). We desired first to delineate the structural basis of lipopolyamine-albumin interactions and, second, to explore possible structure-activity correlates in a well-defined, congeneric series of N-alkyl and -acyl homospermine lead compounds. Fluorescence spectroscopic and isothermal titration calorimetry (ITC) results indicate that these compounds appear to bind to HSA via occupancy of the fatty-acid binding sites on the protein. The acyl and carbamate compounds bind HSA the strongest; the ureido and N-alkyl analogues are significantly weaker, and the branched alkyl compound is weaker still. ITC-derived dissociation constants are weighted almost in their entirety by enthalpic deltaH terms, which is suggestive that the polarizability of the carbonyl groups facilitate, at least in large part, their interactions with HSA. The relative affinities of these lipopolyamines toward HSA is reflected in discernible differences in apparent potencies of LPS-sequestering activity under experimental conditions requiring physiological concentrations of HSA, and also of in vivo pharmacodynamic behavior. These results are likely to be useful in designing analogues with varying pharmacokinetic profiles.
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Affiliation(s)
- Thuan B Nguyen
- Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66047, USA
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Watson J, Wright S, Lucas A, Clarke KL, Viggers J, Cheetham S, Jeffrey P, Porter R, Read KD. Receptor occupancy and brain free fraction. Drug Metab Dispos 2009; 37:753-60. [PMID: 19158315 DOI: 10.1124/dmd.108.022814] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
This study was designed to investigate whether brain unbound concentration (C(u,brain)) is a better predictor of dopamine D(2) receptor occupancy than total brain concentration, cerebrospinal fluid concentration (C(CSF)), or blood unbound concentration (C(u,blood)). The ex vivo D(2) receptor occupancy and concentration-time profiles in cerebrospinal fluid, blood, and brain of six marketed antipsychotic drugs were determined after oral administration in rats at a range of dose levels. The C(u,brain) was estimated from the product of total brain concentration and unbound fraction, which was determined using a brain homogenate method. In conclusion, the C(u,brain) of selected antipsychotic agents is a good predictor of D(2) receptor occupancy in rats. Furthermore, C(u,brain) seems to provide a better prediction of D(2) receptor occupancy than C(CSF) or C(u,blood) for those compounds whose mechanism of entry into brain tissue is influenced by factors other than simple passive diffusion.
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Affiliation(s)
- Jeanette Watson
- Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, Scotland, UK
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Westedt U, Wittmar M, Hellwig M, Hanefeld P, Greiner A, Schaper AK, Kissel T. Paclitaxel releasing films consisting of poly(vinyl alcohol)-graft-poly(lactide-co-glycolide) and their potential as biodegradable stent coatings. J Control Release 2006; 111:235-46. [PMID: 16466824 DOI: 10.1016/j.jconrel.2005.12.012] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2005] [Revised: 12/12/2005] [Accepted: 12/14/2005] [Indexed: 12/20/2022]
Abstract
Although substantial progress in catheter and stent design has contributed to the success of percutaneous transluminal angioplasty (PTA) of atherosclerotic disease, the incidence of restenosis caused by in-stent neointimal hyperplasia remains a serious problem. Therefore, stents with a non-degradable polymer coating showing controlled release of active ingredients have become an attractive option for the site-specific delivery of anti-restenotic agents. Biodegradable coatings using polyesters, namely poly(lactic-co-glycolic acid) (PLGA) and different poly(vinyl alcohol)-graft-poly(lactic-co-glycolic acid) (PVA-g-PLGA) as paclitaxel-eluting stent coating materials were investigated here to evaluate their influence on the release kinetic. Whereas PLGA showed sigmoid release behavior, the paclitaxel release from PVA-g-PLGA films was continuous over 40 days without initial drug burst. Wide angle X-ray diffraction confirmed that paclitaxel is dissolved in the polymer matrix. Paclitaxel crystallization can be observed at a drug load of > or =10%. The effect of drug loading on polymer degradation was studied in films prepared from PVA300-g-PLGA30 with paclitaxel loadings of 5% and 15% over a time period of 6 weeks. The results suggest a surface-like erosion mechanism in films. A model stent (Jostent peripheral) coated with Parylene N, a poly(p-xylylene) (PPX) derivate, was covered with a second layer of PVA300-g-PLGA15, and PVA300-g-PLGA30 by using airbrush method. Morphology of coated stents, and film integrity after expansion from 3.12 to 5 mm was investigated by scanning electron microscopy (SEM). The devices resisted mechanical stress during stent expansion and merit further investigation under in vivo conditions.
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Affiliation(s)
- Ulrich Westedt
- Philipps University Marburg, Faculty of Pharmacy and Biopharmaceutics, Ketzerbach 63, 35032 Marburg, Germany
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Jahrsdörfer B, Blackwell SE, Wooldridge JE, Taylor CM, Weiner GJ. Serum alters the uptake and biologic activity of CpG oligodeoxynucleotides in B cell chronic lymphocytic leukemia. Oligonucleotides 2005; 15:51-9. [PMID: 15788900 DOI: 10.1089/oli.2005.15.51] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Immunostimulatory CpG-containing oligodeoxynucleotides (CpG ODN) have a number of effects on B cells, including upregulation of immunogenic molecules, and, therefore, appear attractive as potential components of immunotherapy for B cell chronic lymphocytic leukemia (B-CLL). Previous in vitro studies investigating the effect of CpG ODN on B-CLL cells used serum-low conditions and did not account for the longer-half life of CpG ODN in vitro. The present study was designed to explore how the presence of serum and exposure time affect CpG ODN-mediated changes on B-CLL cells. The optimal concentration for CpG ODN-mediated effects in the presence of 100% serum or plasma was higher (10-20 microg/ml) than for serum-low conditions. Maximal CpG ODN-mediated effects required the presence of ODN for no longer than 3 hours. The inhibition of CpG ODN-mediated effects by serum correlated with lower uptake of ODN into B-CLL cells in the presence of serum. A threshold effect on biologic response was observed, with a given amount of ODN internalized, resulting in phenotypic changes. In conclusion, systemic short-term application of CpG ODN appears to be sufficient to induce phenotypic changes, but higher doses of CpG ODN than previously thought may be necessary because of inhibition of their uptake by serum.
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Affiliation(s)
- Bernd Jahrsdörfer
- The Holden Comprehensive Cancer Center, University of Iowa, Iowa City, IA 52242, USA
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27
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Xu BQ, Ishii M, Ding LR, Fischer NE, Inaba T. Interaction of serum proteins with CYP isoforms in human liver microsomes: inhibitory effects of human and bovine albumin, alpha-globulins, alpha-1-acid glycoproteins and gamma-globulins on CYP2C19 and CYP2D6. Life Sci 2003; 72:1953-62. [PMID: 12597994 DOI: 10.1016/s0024-3205(03)00093-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The effects of serum proteins on the in vitro hydroxylation pathways of mephenytoin (CYP2C19) and debrisoquine (CYP2D6) were studied to enhance the predictability of in vivo drug metabolism from in vitro assays. Both CYP substrates are known to be weakly bound to albumin and the applicability of the free drug hypothesis was further appraised. Since bovine serum albumin (BSA) is used widely in in vitro assays, a comparison between human and bovine proteins was made. Four major serum proteins were studied: albumin, alpha1-acid glycoprotein (AGP), alpha- and gamma-globulins. Human serum albumin (HSA) inhibited both CYP activities about 20% more than BSA. The addition of human alpha-globulins, but not the bovine protein, resulted in marked reduction of 86% and 41% in CYP2C19 and CYP2D6 activities, respectively. This reduction of activity was strikingly greater than the fraction bound (14 and 22%, respectively). The inhibition was of the competitive type and the Ki values of human alpha-globulins on CYP2C19 and CYP2D6 were found to be 0.45% (4.5 mg/ml) and 3.5% (35 mg/ml), respectively. The effect of both human and bovine gamma-globulins on CYP isoforms was negligible. The Ki values of human and bovine AGP for CYP2C19 were 1.84% (420 microM) and 0.93% (210 microM), respectively. For HSA, human alpha-globulins and human and bovine AGP, the strongly decreased CYP activities in vitro cannot be explained by the free drug hypothesis. A direct interaction of these serum proteins with CYP enzymes is postulated. Differential effects of bovine and human serum proteins and CYP specific inhibition were observed.
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Affiliation(s)
- Bang Qian Xu
- Department of Pharmacology, Faculty of Medicine, University of Toronto, Canada M5S1A8
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28
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Abstract
The growing use of local drug delivery to vascular tissues has increased interest in hydrophobic compounds. The binding of these drugs to serum proteins raises their levels in solution, but hinders their distribution through tissues. Inside the arterial interstitium, viscous and steric forces and binding interactions impede drug motion. As such, this might be the ideal scenario for increasing the amount of drug delivered to, and residence time within, arterial tissues. We quantified carrier-mediated transport for paclitaxel, a model hydrophobic agent with potential use in proliferative vascular diseases, by determining, in the presence or absence of carrier proteins, the maximum concentration of drug in aqueous solution, the diffusivity in free solution, and the diffusivity in arterial tissues. Whereas solubility of paclitaxel was raised 8.1-, 21-, and 57-fold by physiologic levels of alpha(1)-acid glycoproteins, bovine serum albumin, and calf serum over that in protein-free solution, diffusivity of paclitaxel in free solution was reduced by 41, 49, and 74%, respectively. When paclitaxel mixed in these solutions was applied to arteries both in vitro and in vivo, drug was more abundant at the tissue interface, but protein carriers tended to retain drug in the lumen. Once within the tissue, these proteins did not affect the rate at which drug traverses the tissue because this hydrophobic drug interacted with the abundant fixed proteins and binding sites. The protein binding properties of hydrophobic compounds allow for beneficial effects on transvascular transport, deposition, and distribution, and may enable prolonged effect and rationally guide local and systemic strategies for their administration.
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Affiliation(s)
- M A Lovich
- Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Room 16-343, Cambridge, MA 02139, USA
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Abstract
The blood-brain barrier is formed by the endothelial cells of the brain capillaries. Its primary characteristic is the impermeability of the capillary wall due to the presence of complex tight junctions and a low endocytic activity. Essential nutrients are delivered to the brain by selective transport mechanisms, such as the glucose transporter and a variety of amino acid transporters. Although most drugs enter the brain by passive diffusion through the endothelial cells depending on their lipophilicity, degree of ionization, molecular weight, relative brain tissue and plasma bindings, some others can use specific endogenous transporters. In such cases, binding competition on the transporter with endogenous products or nutrients can occur and limits drug transfer. The blood-brain barrier can be a major impediment for the treatment of diseases of the central nervous system, since many drugs are unable to reach this organ at therapeutic concentrations. Various attempts have been made to overcome the limiting access of drugs to the brain, e.g. chemical modification, development of more hydrophobic analogs or linking an active compound to a specific carrier. Transient opening of the blood-brain barrier in humans has been achieved by intracarotid infusion of hypertonic mannitol solutions or of bradykinin analogs. Another way to increase or decrease brain delivery of drugs is to modulate the P-glycoprotein (P-gp) whose substrates are actively pumped out the cell into the capillary lumen. Many P-gp inhibitors or inducers are available to enhance the therapeutic effects of centrally acting drugs or to decrease central adverse effects of peripherally active drugs.
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Affiliation(s)
- P Jolliet-Riant
- Service de Pharmacologie, Faculté de Médecine de Créteil, Université Paris XII
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Jolliet-Riant P, Boukef MF, Duché JC, Simon N, Tillement JP. The genetic variant A of human alpha 1-acid glycoprotein limits the blood to brain transfer of drugs it binds. Life Sci 1998; 62:PL219-26. [PMID: 9570346 DOI: 10.1016/s0024-3205(98)00061-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The objective of this work was to check the effects of alpha-1 acid glycoprotein (AAG) and of its components, A and F1/S genetic variants, on the brain transfer of drugs they bind in plasma. The relevant extractions of six basic drugs, highly bound to AAG, were measured. We chose three drugs selectively bound to the A variant, disopyramide, imipramine and methadone, one drug mainly bound to the mixture F1/S, mifepristone, and two drugs which were simultaneously bound to the variant A and the mixture F1/S, propranolol and chlorpromazine. Their brain extraction were investigated in rats using the carotid injection technique and the capillary depletion method. Injected drugs were dissolved either in buffer, either in native AAG containing the three variants (A, F1 and S), either in variant A or in variant F1/S solutions. Brain extractions of disopyramide, imipramine and methadone were significantly reduced by native AAG and by variant A. Drug's plasma retention was related to their preferential and almost exclusive binding to A variant, both of them exhibiting the same decrease in brain transfer as compared to a buffered solution. At the opposite, there were no significative differences between the extraction either in buffer, either in AAG or in F1/S solutions, of drugs both bound to A variant and F1/S mixture (chlorpromazine and propranolol) or to the F1/S mixture (mifepristone). In serum, the retentional effect of the A variant on the extraction of disopyramide and imipramine was counteracted by the presence of albumin and lipoproteins, which simultaneously bind these two drugs at a high extent and act as permissive binders. We conclude that AAG binding decreases brain drug transfer when the A variant is mainly and almost exclusively involved in the binding. On the contrary, the entire fraction of the tested drugs when bound exclusively or partly to the mixture F1/S is available for transfer into the brain.
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Affiliation(s)
- P Jolliet-Riant
- Service de Pharmacologie, Faculté de Médecine de Créteil-Paris XII, Creteil, France.
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Jolliet P, Simon N, Brée F, Urien S, Pagliara A, Carrupt PA, Testa B, Tillement JP. Blood-to-brain transfer of various oxicams: effects of plasma binding on their brain delivery. Pharm Res 1997; 14:650-6. [PMID: 9165538 DOI: 10.1023/a:1012165414610] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
PURPOSE The objective of this work was to assess the influence of binding to plasma proteins and to serum on the brain extraction of four antiinflammatory oxicams. METHODS The brain extraction of isoxicam, tenoxicam, meloxicam and piroxicam was investigated in rats using the carotid injection technique. Blood protein binding parameters were determined by equilibrium dialysis using human serum, human serum albumin (HSA) and alpha-l-acid glycoprotein (AAG) solutions at various concentrations. RESULTS All oxicams had low values of brain extraction, between 19% and 39% when dissolved in serum, i.e. under physiological conditions. Brain efflux rate constants calculated from the wash-out curves were the same in the absence or presence of serum. Brain efflux was inversely related to the polarity of the oxicams, such that the higher their H-bonding capacity, the lower their brain efflux. The free dialyzable drug fraction was inversely related to protein concentration. However, rat brain extraction was always higher than expected from in vitro measurements of the dialyzable fraction. CONCLUSIONS Except for piroxicam whose brain extraction was partially decreased in the presence of proteins, the serum unbound and initially bound fractions of oxicams both seem available for transfer into the brain. Modest affinities for AAG rule out any related effect. More surprising is the apparent lack of effect on brain transfer of the high-affinity binding to HSA and serum. The enhanced brain uptake of meloxicam in the presence of AAG could be a result of interactions between this globular protein and the endothelial wall.
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Affiliation(s)
- P Jolliet
- Service de Pharmacologie, Faculté de Médecine PARIS XII, Créteil, France
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Ozier Y. [Role of substitution albumin therapy in drugs, hormones, electrolytes and miscellanous substances transport]. Ann Fr Anesth Reanim 1996; 15:532-42. [PMID: 8881494 DOI: 10.1016/0750-7658(96)83216-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Human serum albumin (HSA) is quantitatively the most important non specific transport protein. HSA binds a wide variety of both endogenous and exogenous ligands. Hypoalbuminaemia may lead to a decreased plasma binding capability of some compounds. Biological/pharmacological consequences depend on the ligand and the target tissue. Many experimental studies suggest that hypoalbuminaemia may influence the metabolism and toxicity of endogenous ligands (bilirubin, metallic ions, oxygen radicals) and the pharmacological effect of some drugs (among others: furosemide, phenytoin, warfarin). The relevance of such information for human surgical situations remains unclear. Clinical studies are scarce and inconclusive. There is a lack of pertinent data supporting the necessity of HSA infusions in order to maintain a minimal plasma concentration and a convenient plasma transport. However, experimental data indicate that major hypoalbuminaemia should be considered with caution.
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Affiliation(s)
- Y Ozier
- Service d'anesthésie-réanimation chirurgicale, université René-Descartes, Paris V, France
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Minder S, Daniel WA, Clausen J, Bickel MH. Adipose tissue storage of drugs as a function of binding competition. In-vitro studies with distribution dialysis. J Pharm Pharmacol 1994; 46:313-5. [PMID: 7914229 DOI: 10.1111/j.2042-7158.1994.tb03801.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Distribution dialysis was used to study binding competition between homogenates of adipose tissue and of lean tissues. The concentration ratios adipose/X (X = blood, muscle, lung, liver) of eight lipophilic drugs were determined in the absence and in the presence of a competing binding system X. With drugs which do not undergo storage in adipose tissue in-vivo, yet have a high volume of distribution, such as imipramine or desipramine, there was strong binding competition, and the balance of distribution was shifted from adipose to lean tissues. In the case of indomethacin with a low volume of distribution this shift was from adipose tissue to blood. With diazepam there was a marked binding competition which was not, however, sufficient to shift the balance of distribution away from adipose tissue. Binding competition was negligible with thiopentone. In contrast, with the equally lipophilic hexethal a moderate binding competition was observed. This is consistent with a decreased adipose tissue storage of the latter barbiturate. It is concluded that binding competition exists not only between blood and tissues but also among individual tissues. It is suggested that occurrence and extent of adipose tissue storage of drugs are determined by binding competition between lean and adipose tissues and, more generally, that distribution of lipophilic drugs is largely a function of binding competition.
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Affiliation(s)
- S Minder
- Department of Pharmacology, University of Berne, Switzerland
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Abstract
The ligands are generally bound in plasma to a significant extent by several transport proteins (both high and low affinity), irrespective of their endogenous or exogenous origin. The protein binding of endogenous compounds (such as hormones) exhibits higher affinity and specificity than those of exogenous compounds (such as drugs). For plasma proteins that bind the same ligand(s), structural similarities or a common genetic origin may be found, although this is not a general rule. Alterations in ligand binding may be due to modifications of either the structure or the level of the binding protein. These modifications may result from genetic make up, physiology or pathology. In some situations, plasma binding may impair the distribution of drugs to tissues, with drug distribution then mainly restricted to the distribution compartment of the drug-binding protein. In other instances, the plasma drug-binding is permissive, and does not limit drug distribution to tissues. A given drug-transport protein system may have either a permissive or a restrictive effect on the drug distribution, depending on the tissue. The physiological significance of the high-affinity transport proteins is not completely understood. These proteins may increase the plasma concentration of poorly hydrosoluble ligands, ensure a more uniform tissue distribution and increase the life of the ligands. The life of the protein may also be increased by ligand binding. High-affinity transport proteins are also involved in some specific carrier mediated transfer mechanisms. It is possible to demonstrate structure-binding relationships or binding selectivity for the plasma transport proteins, but these are quite independent of relationships observed at the receptor level.
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Affiliation(s)
- F Hervé
- Laboratoire Hospitalo-Universitaire de Pharmacologie, Université Paris XII, Centre Hospitalier Intercommunal, Créteil, France
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35
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Abstract
The myocardial uptake and pharmacodynamics of quinidine were examined in the isolated perfused rat heart preparation under conditions of varying concentrations of bovine alpha 1-acidglycoprotein (AAG) in the perfusate. Three hearts were perfused for five consecutive 35 min phases with buffer containing quinidine and AAG in concentrations of 0, 0.1, 0.5, 1.5 and 0 g/L, in that order, with a 55 min washout period between each phase. The equilibration rate constant for the quinidine output concentration increased with increasing AAG concentration, but not as much as predicted by the conventional pharmacokinetic uptake model, which assumes constant capillary permeability among the phases. Estimates of the permeability surface product for the two zero AAG phases (17.7 +/- 1.91 and 19.1 +/- 0.82 mL/min/g) were significantly greater than those for the three AAG phases (8.94 +/- 0.99, 8.70 +/- 0.26, 9.01 +/- 0.26 mL/min/g; P < 0.05). This effect of AAG is the same as that observed previously by us with bovine serum albumin in this same experimental preparation. This suggests that the mechanism of reduced capillary permeability is the same for both proteins, i.e., the formation of a steric barrier to paracellular transport rather than an electrostatic barrier. There was a direct, linear relationship between lengthening of the QT interval of the electrocardiogram and total and unbound quinidine concentrations, but the relationship for unbound concentration was independent of quinidine unbound fraction. Therefore, the electrocardiogram effect of quinidine was directly related to the circulating unbound rather than total drug concentration.
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Affiliation(s)
- J L Huang
- Department of Pharmaceutics, Victorian College of Pharmacy, Melbourne, Australia
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36
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Abstract
Relationships between the binding and the distribution of drugs have been studied in vitro and compared with in vivo data. By use of a standardized technique of distribution dialysis, 10 model drugs were allowed to be distributed among blood and homogenates of seven tissues. The drugs represented a variety of distinct molecules with different lipophilicities, ionization constants, and binding characteristics. The tissue/blood drug concentration ratios were below unity for salicylic acid and phenylbutazone, at about unity for antipyrine (phenazone) and morphine, and above unity for two barbiturates and four basic lipophilic drugs. The binding of the 10 drugs to blood and homogenates of seven tissues was determined by use of conventional equilibrium dialysis and experimental conditions identical to those used in distribution dialysis. From these binding values (free fractions), the theoretical concentration ratios were calculated. There was a good correlation between the calculated values and those determined by distribution dialysis. Thus, the distribution of drugs in the in vitro model of distribution dialysis clearly is the result of binding competition and is predictable from binding values. The correlation between distribution in vitro (or calculated from binding values) and distribution in vivo, on the basis of literature data, indicated a reasonable agreement for antipyrine and the acidic lipophilic drugs used, as well as for the basic lipophilic drugs, with respect to the brain, muscle, and adipose tissue. However, the distribution of the latter drugs in the lungs, liver, and kidneys was grossly underestimated.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- J Clausen
- Department of Pharmacology, University of Berne, Switzerland
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37
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Malmary MF, Kabbaj K, Labat C, Batalla A, Houti I, Moussamih S, Oustrin J. Chronopharmacokinetics of Cyclosporine A in the Wistar rat following oral administration. Eur J Drug Metab Pharmacokinet 1992; 17:135-44. [PMID: 1425812 DOI: 10.1007/bf03188782] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The pharmacokinetics of Cyclosporine A (CsA) was studied in male Wistar rats weighting 300 +/- 50 g trained to a 12:12 light-dark cycle. Oral administration (40 mg/kg) was performed at 1 of 4 different temporal stages: 09.00 h, 15.00 h, 21.00 h or 03.00 h (local time) i.e. 0200, 0800, 1400 or 2000 HALO (hours after light on). Blood samples were collected over 72-96 h after dosing, plasma was separated by centrifugation at 37 degrees C and stored frozen until assay, using radioimmunoassay (RIA). Two experiments were performed: the first with 4 groups of 48 rats and a non-specific polyclonal antibody (P-RIA); and the second with only 2 groups of 48 rats and a more specific monoclonal antibody (M-RIA). Plasma concentration data were evaluated with model-based linear pharmacokinetic concepts, with apparent zero-order or first-order absorption and n-exponential disposition (n = 1, 2 or 3): models MN0 or MN1. A compartment-independent approach was also conducted and led to area under the plasma concentration-time curve (AUC) and mean residence time (MRT) determinations. A comparison of the pharmacokinetic profiles across time of administration indicates that absorption, first-pass metabolism and tissue distribution of CsA in the rat are circadian-dosing stage dependent.
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Affiliation(s)
- M F Malmary
- Equipe de Chronopharmacologie, Faculté des Sciences Pharmaceutiques, Toulouse, France
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38
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Abstract
The apparent diffusion coefficient of a bound drug, cefoperazone, was studied. The protein binding of cefoperazone was studied by voltammetry, a technique which permitted instant measurements. The apparent diffusion coefficients were similar in agar and fibrin and lower in rat brain tissue. The influence of protein on the value of the apparent diffusion coefficient was negligible. The hypothesis that only the free drug diffuses was supported. The percentage of binding determined by voltammetry corresponded to the true concentration of drug which diffuses and is much lower than the percentage of binding determined by the ultrafiltration centrifugation method. This discrepancy could be explained by the rate of dissociation of the protein-drug complex.
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Affiliation(s)
- A Meulemans
- Laboratoire de Biophysique, Faculté de Médecine Xavier-Bichat, Paris, France
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