Targeting drugs to the colon is one of the modern research areas in pharmaceutical sciences at the deciding time, place and exact amount, and improving patient flexibility, compliance and bioavailability. To reach doing well colon targeted drug delivery, a drug necessitate to be protected from degradation, release and absorption in the upper part of the GI tract and then to be ensure abrupt or controlled release in the proximal colon. The colon is a site wherever both local and systemic delivery of drugs can take place. Local delivery allows topical treatment of inflammatory disease like constipation, chronic pancreatitis, reatactomy and colonic cancer etc. However, treatment can be made useful if the drugs be able to target directly into the colon; thereby reducing the systemic side effect and improve drug therapy or bioavailability in the upper GI tract. This article also discuss different country patent and approach like prodrugs, pH dependent, time dependent, azo-hydrogels, pressure controlled, pulsatile and microbially triggered drug delivery system, and evaluation for site specific drug delivery to colon. This overview focused on more than 100 patents available in different colonic drug delivery on current days. It is demanding areas for future investigate and hold plenty of promise for novel and efficient approach for targeted drug delivery system.