NOVEL APPROACHES OF COLON TARGETED DRUG DELIVERY SYSTEMS: A REVIEW

Samir Kumar Patra, Annada Prasad Mahapatra, Bijay Kumar Sahoo*

ABSTRACT

The colon is believed to be a suitable absorption site for peptides and protein drugs for the reasons like less diversity and intensity of digestive enzymes, less proteolytic activity of colon mucosa leading to better protection from hydrolysis and enzymatic degradation in duodenum and jejunum, greater systemic bioavailability and long colon residence time (5 days) and high responsiveness to absorption enhancers. The colon is a site where both local and systemic delivery of drugs can take place. Local delivery allows topical treatment of inflammatory bowel disease. However, treatment can be made effective if the drugs can be targeted directly into the colon, thereby reducing the systemic side effects. Colon target drug delivery system (CDDS) is highly desirable for local treatment of a variety of bowel diseases such as ulcerative colitis, Crohn’s disease, amebiasis, colonic cancer, local treatment of colonic pathologies, and systemic delivery of protein and peptide drugs. This review, mainly compares the primary approaches for CDDS (Colon Specific Drug Delivery) namely prodrugs, pH and time dependent systems, and microbially triggered systems, which achieved limited success and had limitations as compared with newer CDDS namely pressure controlled colonic delivery capsules, CODESTM, and osmotic controlled drug delivery which are unique in terms of achieving in vivo site specificity, and feasibility of manufacturing process.

Keywords: Colon Drug Delivery, Polymer coated, Prodrug, Osmotic pressure.