Oral drug administration by swallowing is the most patient compliant method and remains the most popular.^1,2  However, it faces a series of limitations related to acid gastric medium, the low aqueous solubility of most drugs, the presence of the intestinal mucosa that is formed by an apical hydrophilic mucus layer and the intestinal epithelium bound by tight junctions that preclude paracellular permeability and the portal vein circulation.²  Altogether, these properties may result in degradation, incomplete absorption and low bioavailability. The gastrointestinal residence time of conventional pharmaceutical formulations is relatively short (a few hours) and oral sustained release, which...