Applications of Epithelial Cell Culture in Studies of Drug Transport

The popularity of epithelial cell lines in studies of drug transport processes can probably be explained by the ease with which new information is derived from these rather simple in vitro models. Drug transport studies in epithelial cell monolayers grown on permeable supports are easy to perform under controlled conditions, resulting in the generation of a wealth of information. This information can generally be relatively easily translated into fundamental principles, since the homogenous epithelial cell cultures lack the complexity and variability found in more complex whole tissue models. In fact, much of our more recent knowledge about active and passive drug transport mechanisms has been obtained from studies in various epithelial cell cultures (1 ). The good correlation between passive drug transport through various epithelial cell monolayers and that seen across the human intestine in vivo now makes it possible to use the cell cultures for studies on structure-absorption relationships (examples are found in refs. 2-4 ). Indeed, both cell culture and transport experiments across epithelial cell monolayers have been automated, and these models are now used as a screening tool in drug discovery programs in many drug companies for the prediction of intestinal drug permeability.