Author: Ward, P.D.; Tippin, T.K.; Thakker, D.R.
intestinal epithelium is a major barrier to the absorption of hydrophilic drugs. The presence of intercellular junctional complexes, particularly the tight junctions (zona occludens), renders the epithelium impervious to hydrophilic drugs, which cannot diffuse across the cells through the lipid bilayer of the cell membranes, design of agents that can effectively and safely increase paracellular permeability via modulation of tight junctions, the tight junction barrier function is physiologically important, in that it maintains electrolyte gradients and membrane polarity and keeps macromolecules out of the body,
