ANITINERARY TO ACCESS THE COLON

Abstract

Although oral delivery has become a widely accepted route of administration of therapeutic drugs, the gastrointestinal tract presents several formidable barriers to drug delivery. The delivery of drugs to the colon has a number of important implications in the field of pharmacotherapy. Drugs that are destroyed by the acidic environment of the stomach or metabolized by pancreatic enzymes are only slightly absorbed in the colon. Targeted delivery of drugs to the colon has attracted much interest recently for local treatment of a variety of colonic diseases such as irritable bowel syndrome (IBS), colorectal cancer and inflammatory bowel diseases (IBD), which includes both ulcerative colitis and crohn's disease. The colon is also receiving significant attention as a portal for the entry of drugs into the systemic circulation. A variety of delivery strategies and systems have been proposed for colonic targeting.This article shall review the diversestrategies used to target the drug to the colon.The various features of different approaches allowing locally restricted drug delivery to the inflamed colon are discussed including the main physiological issues and histological changes of the colon as its cancer develops.