High-throughput Caco-2 cell permeability screening by cassette dosing and sample pooling approaches using direct injection/on-line guard cartridge extraction/tandem mass spectrometry

A method for high-throughput Caco-2 permeability screening of drug candidat es has been developed using thirteen generic drugs as test compounds. The h igh throughput was achieved by either a sample pooling or a cassette dosing approach, along with the use of a rapid, simple and sensitive direct injec tion/on-line guard cartridge extraction/tandem mass spectrometric assay tha t was also developed in this study. It was of concern that possible drug-dr ug interactions (e.g., inhibition of P-glycoprotein-mediated transport of a drug by another, and/or competition of the drugs for transport pathways), when the cassette dosing regimen was implemented, may give rise to inconsis tent results compared with those attained by a traditional single-drug dosi ng approach. However, the apparent permeability coefficients of the test dr ugs across Caco-2 monolayers measured by the sample pooling or cassette dos ing (up to five drugs co-administered in this study) strategy were in good conformity with the data obtained by single-drug dosing followed by discret e sample analysis. Copyright (C) 2000 John Wiley & Sons, Ltd.