Design and Evaluation of Colon Specific Drug Delivery System

Colonic drug delivery has gained increased importance not just for the delivery of the drugs for the treatment of local diseases associated with the colon like Crohn¿s diseases, ulcerative colitis, irritable bowl syndrome but also for the potential it holds for the systemic delivery of proteins and therapeutic peptides. Targeted drug delivery to the colon would therefore, ensure direct treatment at the disease site and, consequently, lower dosing and reducing systemic side effects. The most critical challenge in such drug delivery approach is to preserve the formulation during its passage through the stomach and about first six meters of small intestine. In the present investigations, two drugs mesalamine and budesonide was selected for ulcerative colitis in colon. An attempt was made to prepare formulations which could not release the drug into stomach for up to 2 h. which is residence time for it, also it could not release the drug into small intestine up to 3 h. which is residence time for it and could release the drug up to 24 h to 3 days which is residence time for colon. These attempts formulate the colon targeted controlled release dosage form for ulcerative colitis.