The present invention provides a delivery system to colon. The delivery system comprises a drug in combination with a matrix, wherein the matrix comprises a polymer of pH independent or dependent or combinations thereof. According to the invention, the matrix is resistant to chemical and enzymatic degradation in the stomach and small intestine. The system is useful for targeting drugs to the colon in order to treat colonic disease. The system is also useful for enteric administration of drugs such as non-steroidal anti- inflammatory drugs which are otherwise needed to get absorbed in small intestine or either not stable in upper gastrointestinal tract.