Sodium caprate elicits dilatations in human intestinal tight junctions and enhances drug absorption by the paracellular route

The effects of the absorption enhancer sodium caprate on human intestinal epithelial cells were investigated using Caco-2 cell monolayers. The effects on epithelial integrity and drug transport are dependent on time and concentration and are decreased by Ca2+, most likely through the formation of Ca2+ soaps. Morphological data indicate that exposure to sodium caprate results in cytoskeletal changes and in structural alterations of the tight junctions in the form of dilatations, while the effects on the apical cell membranes are limited. We conclude that sodium caprate increases the absorption of drugs mainly by the paracellular route.