Abstract:
Oral, colon-specific drug delivery has attracted much interest recently. It is of considerable
advantage to have an oral drug delivery system that could be targeted to the colon. This
could be either for the local treatment of diseases such ulcerative colitis, irritable bowel
syndrome and tumors, or to exploit the colon as a preferred region for systemic drug
absorption, possibly as a site for polypeptides absorption. Delivery systems that rely on pH
and/or time dependent mechanisms for drug release are less reliable in achieving consistent
site-specific drug delivery to the colon. The successful delivery of prodrugs of 5-
aminosalicylic acid is an evident of the potential of the bacterial flora. However, it has been
less successful in the development of polysaccharide – based dosage forms or synthetic
polymer coatings. This work was aimed at the development of ketoprofen microcapsules
based on polysaccharide coating. The in-vitro release studies in simulated colonic media
showed sensitivity of such dosage form to bacterial enzymes with subsequent increase in
dissolution rate. The in -vivo profiles in dogs showed that the tested product exhibited a lagtime prior to commencement of drug absorption. The plasma profiles were not
accompanied by a high initial plasma concentration associated with conventional dosage
forms
