Caco-2 cell monolayers as a model for studies of drug transport across human intestinal epithelium

The gastrointestinal (GI) tract has always been of interest for drug delivery owing to the convenience of oral administration. However, the successful development of oral drugs has been challenged by a variety of barriers in the GI tract. One of the barriers that restrict the bioavailability of orally administered drugs is the epithelium of the intestinal mucosa that lines the surface of the GI tract. The intestinal mucosa is both a physical and a biochemical barrier, separating the external environment from the internal milieu of the body (Pauletti et al., 1997).