Drugs and Polymers Used for Colon Specific Drug Delivery System with Current Trends: A Systematic Review

Abstract

Due to greater flexibility in design of dosage form and high patient compatibility, oral route of administration is the most preferred route but the gastrointestinal tract has many types of other undefeatable barriers to drug delivery. ‎In oral colon-specific drug delivery system, colon has a large amount of lymphoma tissue which facilitates direct absorption into the blood, negligible brush border membrane activity, and much less pancreatic enzymatic activity as compared with the small intestine. Colon in recent days offers great advantages for drug its physiological condition enriched for prolonging drug release time. Therefore, we can deliver the drug for systemic as well as local action through the colon. Local delivery mainly includes topical treatment of inflammatory bowel disease. This treatment can be made effective by targeting the drugs directly into the colon and we can reduce the systemic side effects. This review mainly includes drugs and polymers used so far in colonic drug delivery system and the primary approaches for CDDS (Colon Specific Drug Delivery) such as formation of prodrug, coating with pH dependent polymers, timed released system, designing formulation using polysaccharides, hydrogels, bioadhesive system, pressure-dependent drug delivery, CODES^TM, osmotic drug delivery system which are unique in terms of achieving in vivo site specificity, and feasibility of manufacturing process.

Keywords: Colon drug delivery system, prodrug, pH, microbially triggered, CODES