Colon Specific Drug Delivery System Design and Development by using Chitosan Copolymers

Abstract

Now a day, various routes of drug administration have been explored for the effective delivery of the drug. However, the oral route of drug administration is widely acceptable by the patient as it is most convenient route of drug administration and most of the drugs are absorbed adequately through the gastrointestinal tract (GIT) membrane. Because of the efficient absorption of the drug from the upper part of GIT, some time it becomes problematic for the treatment of the diseases associated with lower intestinal part i.e. colon or large intestine. Hence, it is required to deliver in effective drug concentrations at the large intestine for the treatment of colonic diseases i.e. inflammatory bowel diseases (IBD) such as ulcerative colitis and Crohn s disease. The effective drug concentration could be reached to the colon either by reducing the drug absorption from the stomach and small intestine or by direct delivery of the drugs to the colon. Recently, research has focused on the drug delivery to the large bowel after oral administration. newline Moreover, some of the drug molecules are very sensitive to the upper GIT environment i.e. presence of surfactants (bile salts), enzymes (from both intracellular and extracellular sources) and pH, which could destroy the drug molecule. This results an unacceptable variability in bioavailability of even stable drug molecule. Most of these complicating factors to drug absorption are notorious in the upper GIT especially in the case of peptides and proteins. newline