Colon targeted drug delivery systems

Drugs have been targeted to the colon for the treatment of several diseases like ulcerative colitis, amoebiasis, chron's disease and colorectal cancer. Such conditions require local action of the drugs rather than systemic absorption. Several drug delivery systems have been designed to release drugs specifically in the large intestine to improve therapeutic efficacy, to reduce dose of drugs, and amount to low systemic absorption resulting in fewer side effects. Several proteins or peptides which are degraded in the stomach and small intestine due to the abundance of digestive enzymes are also targeted to the colon for systemic absorption and improved therapeutic efficacy (1). However, several challenges are still being faced by researchers for selectively targeting drugs to the colon and newer approaches for drug targeting are being developed.