Polymer-based drug delivery: the quest for local targeting of inflamed intestinal mucosa.

Colon-specific drug delivery has found important applications in the wide array of diseases affecting the lower intestinal tract. Recent developments and advancements in the polymer-based colonic delivery ensure targeted therapeutics with reduced systemic adverse effects. Latest progress in the understanding of polymer science has decorated a polymer-based formulation with a number of special features, which may prove effective in the localized drug targeting at specific sites of the intestine. Upon oral administration, polymeric vehicles or polymer-coated formulations serve to protect the drug from premature release and degradation in the upper gastrointestinal tract. Moreover, it also facilitates the selective accumulation and controlled release of the drug at inflamed sites of the colon. This review article focuses on a wide coverage of major polymers, their modifications, pros and cons, mechanism of colon targeting and applications as a vehicle system for colonic drug delivery, with a special emphasis on the inflammatory bowel disease.