A Review on Colonic Drug Delivery System

Colon specific drug delivery has gained a much importance for the delivery of drugs to treat the both local and systemic diseases. Local diseases include Chron's disease, ulcerative colitis, and colorectal cancer. Number of other serious disorders like nocturnal asthma, arthritis and angina can also be cured by these techniques. Colonic delivery is a good candidature for delivery of proteins peptides and vaccines where the enzymatic degradation and the hydrolysis of proteins can be minimized and increases the systemic bioavailability. A drug should be protected from the absorption and the upper GI environment to achieve the successful colonic drug delivery. The colon specific delivery of drugs to the target receptor sites has the advantage to reduce the side effects and improves the therapeutic response. Colon specific drug delivery are being developed by taking advantage of the luminal P^H conditions and the presence of microbial enzymes such as azoreductase, pectinase, dextranase…etc. This review mainly reveals on the various concepts and approaches include Prodrug, P^H and time dependent systems and microbially triggered systems used in the development of colon specific drug delivery. This also focuses on the novel approaches namely Pressure controlled colonic delivery, osmotic controlled drug delivery and CODES^TM. In vitro and in vivo evaluation parameters has been discussed here.