Novel Approaches For Colon Site-Specific Drug Delivery: An Overview Of Recent Advancements

Abstract

Nowadays, various routes of administration have been explored for the effective delivery of the drug to the target site. The oral route is considered to be the most convenient for the administration of drugs to patients. But it has a serious drawback in conditions where localized delivery of the drug in the colon is required. The colon-targeted drug delivery system (CDDS) is a potential approach for systemic and topical drug delivery in treating inflammatory bowel diseases such as ulcerative colitis, Crohn’s disease, colon cancer, and amoebiasis. CDDS would provide direct treatment at the site of the disease, reduced dose, and reduced systemic adverse effects. CDDS should be able to release the drug into the colon, indicating that neither drug release nor absorption should take place in the stomach or small intestine, nor should the bioactive agent be degraded there. Instead, the drug should only be released and absorbed when it reaches the colon. The colon is a site for both local and systemic drug delivery. This review mainly compares the primary approaches for CDDS (Colon Specific Drug Delivery) namely prodrugs, pH and time-dependent systems, and microbially triggered systems, which achieved limited success and had limitations as compared with newer CDDS namely pressure-controlled colonic delivery capsules, CODESTM, and osmotic controlled drug delivery systems. The review is also focused on the possible benefits and issues associated with the novel colon-targeted drug delivery system. Recent advancements in various approaches for designing colon-targeted drug delivery systems and their pharmaceutical applications are covered with a particular emphasis on formulation technologies.