Caco-2 cells as a model for intestinal absorption.

The Caco-2 cell system, a well characterized intestinal in vitro model, makes it possible to evaluate the ability of chemicals to cross the intestinal barrier, as well as to study their transport mechanisms. Permeability values estimated with this model correlate well with human in vivo absorption data for many drugs and chemicals. As a consequence, the use of the Caco-2 cellular model as a permeability assay to predict oral absorption in humans is growing, and its importance is increasing as a screening tool in drug-discovery strategies for the prediction of intestinal drug permeability. Strict observance of the experimental conditions, coupled with careful control of the cell-culture procedures, are crucial for obtaining a meaningful correlation with in vivo data. Because of the intrinsic variability of this absorption model, it is important to highlight that each experimental system must be calibrated with internal reference compounds, to permit data sharing between different laboratories.