An Insight to Colon Targeted Drug Delivery System

Rashmi      Sareen; Nitin      Jain; K.   L.   Dhar

Abstract

Drug targeting is delivery of drug to receptor, organ or any other specific part of body exclusively. Delivery of the drug by the oral route remains the most important route for the administration of medicines to patient. This manuscript highlights organ of digestive system (colon), their size and physiology and transit pattern of dosage forms while travelling through digestive tract. The colon is a site where both local and systemic delivery of drugs can be given. Targeted drug delivery into the colon is highly desirable for local treatment of a variety of bowel diseases such as ulcerative colitis, crohn’s disease and colonic cancer. However the drug can be targeted directly into the colon to reduce the systemic side effects. Precise colon targeted drug delivery requires that the triggering mechanism in the delivery system should only respond to the physiological conditions particular to the colon. Hence, continuous efforts should be focused on designing colon-specific delivery systems with improved site specificity and drug release kinetic to accommodate different therapeutic needs. This review mainly compares different strategies for colon specific drug delivery such as prodrug and polymeric prodrug, which achieved limited success and have limitations as compared with novel colon specific drug delivery systems namely pressure, time, pH and bacteria dependent, chitosan-calcium alginate microparticles, microsponges, nanospheres, nanoparticles, osmotic controlled systems. These novel systems are unique in terms of achieving in-vivo site specificity and feasibility of manufacturing process. The in-vivo evaluation includes various techniques for colon specific drug delivery system such as string technique, endoscopy, radiotelemetry, roentgenography and gamma scintigraphy.

Keywords: Colitis, micro flora, prodrug, pulsatile, strategies, targeting.

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