Received for publication June 26, 2007.
Revised October 18, 2007.
Accepted for publication October 22, 2007.

In Vitro P-glycoprotein Assays to Predict the in Vivo Interactions of P-glycoprotein with Drugs in the Central Nervous System

Abstract

Thirty-one structurally diverse marketed central nervous system (CNS)-active drugs, one active metabolite, and seven non-CNS-active compounds were tested in three P-glycoprotein (P-gp) in vitro assays: transwell assays using MDCK, human MDR1-MDCK and mouse Mdr1a-MDCK cells, ATPase, and Calcein AM inhibition. Additionally, the permeability for these compounds was measured in two in vitro models: PAMPA and apical-to-basolateral apparent permeability in MDCK. The exposure of the same set of compounds in brain and plasma was measured in P-gp knockout (KO) and wild type (WT) mice after subcutaneous administration (Doran et al., 2005). One drug and its metabolite, risperidone and 9-hydroxyrisperidone, of the thirty-two CNS compounds, and six of the seven non-CNS drugs were determined to have positive efflux using ratio of ratios (RR) in MDR1-MDCK vs. MDCK transwell assays. Data from transwell studies correlated well with the brain-to-plasma AUC ratios between P-gp KO and WT mice for the thirty-two CNS compounds. In addition, 3300 Pfizer compounds were tested in MDR1-MDCK and Mdr1a-MDCK transwell assays, with a good correlation (R²=0.92) between the efflux ratios in human MDR1-MDCK and mouse Mdr1a-MDCK. Permeability data showed that the majority of the thirty-two CNS compounds have moderate to high passive permeability. This work has demonstrated that in vitro transporter assays help understand the role P-gp-mediated efflux activity in determining the disposition of CNS drugs in vivo, and the transwell assay is a valuable in vitro assay to evaluate human P-gp interaction with compounds for assessing brain penetration of new chemical entities to treat CNS disorders.

Key words: blood-CNS transport, drug efflux, drug transport, in vitro-in vivo prediction, permeability, p-glycoprotein, transporters

This article has been cited by other articles:

				J. Geyer, O. Gavrilova, and E. Petzinger The Role of P-Glycoprotein in Limiting Brain Penetration of the Peripherally Acting Anticholinergic Overactive Bladder Drug Trospium Chloride Drug Metab. Dispos., July 1, 2009; 37(7): 1371 - 1374. [Abstract] [Full Text] [PDF]

				L. Zhou, K. Schmidt, F. R. Nelson, V. Zelesky, M. D. Troutman, and B. Feng The Effect of Breast Cancer Resistance Protein and P-Glycoprotein on the Brain Penetration of Flavopiridol, Imatinib Mesylate (Gleevec), Prazosin, and 2-Methoxy-3-(4-(2-(5-methyl-2-phenyloxazol-4-yl)ethoxy)phenyl)propanoic Acid (PF-407288) in Mice Drug Metab. Dispos., May 1, 2009; 37(5): 946 - 955. [Abstract] [Full Text] [PDF]

				B. Feng, J. J. Xu, Y.-A. Bi, R. Mireles, R. Davidson, D. B. Duignan, S. Campbell, V. E. Kostrubsky, M. C. Dunn, A. R. Smith, et al. Role of Hepatic Transporters in the Disposition and Hepatotoxicity of a HER2 Tyrosine Kinase Inhibitor CP-724,714 Toxicol. Sci., April 1, 2009; 108(2): 492 - 500. [Abstract] [Full Text] [PDF]

				Y. Kitamura, H. Koto, S. Matsuura, T. Kawabata, H. Tsuchiya, H. Kusuhara, H. Tsujimoto, and Y. Sugiyama Modest Effect of Impaired P-glycoprotein on the Plasma Concentrations of Fexofenadine, Quinidine, and Loperamide following Oral Administration in Collies Drug Metab. Dispos., May 1, 2008; 36(5): 807 - 810. [Abstract] [Full Text] [PDF]

				X. Liu, C. Chen, and B. J. Smith Progress in Brain Penetration Evaluation in Drug Discovery and Development J. Pharmacol. Exp. Ther., May 1, 2008; 325(2): 349 - 356. [Abstract] [Full Text] [PDF]