Cornelia M. Keck, Aiman H. Hommoss, and Rainer H. Mu¨ller Department of Pharmaceutical Technology, Biopharmaceutics, and Nutricosmetics,


Small-sized particulate carriers (microparticles and nanoparticles) are under investigation to enhance oral drug absorption and/or to modulate blood concentration profiles for optimized therapy by controlling drug release from such particles. A further potential benefit of development includes increased retention of formulations in the gastrointestinal tract (GIT). This in turn provides a longer time for drug absorption to occur and is especially useful in the case of active pharmaceutical ingredients (API) that have a narrow absorption window. A slower passage through the absorption window may enhance the bioavailability of an API. One approach to further increase the bioavailability is the combination of mucoadhesive polymers with particulates, which can be achieved by coating and/or stabilizing the particles with mucoadhesive layers such as polyacrylates or chitosan (1,2).