Colonic drug delivery systems as multiunit potential: Therapeutic strategies and opportunities

Abstract

Multiparticulates are formulations in which the active substance is present as small independent subunits. Small size enables the multiparticulates to reach the colon quickly, and they are retained in the ascending colon for a relatively longer period of time. Prevention of the drug release in the stomach and subsequent release of the drug in the colon, is the requirement of colon-specific delivery. This can be achieved better by the development of the multiparticulate systems instead of single-unit systems. Other advantages of multiparticulate systems over single-unit systems include increased bioavailability, reduced risk of systemic toxicity and local irritation, predictable gastric emptying and hence better/reproducible pharmacokinetic behaviour. Present chapter reviews research efforts for development of multiparticulate for colon targeting utilizing different strategies like prodrug, bioadhesion, pH sensitivity, etc.