Microsphere

In the recent year colonic drug delivery has gained importance for delivery of drug for the treatment of local diseases associated with colon and systemic delivery of therapeutic peptides and proteins. Treatment could be more effective if it is possible for drug to be directly delivered to colon. During the last decade there are new developments in site-specific formulations for targeting drug to the colon. Colon has proved to be a site for the absorption of poorly soluble drugs. Micro carriers as colon drug delivery System has gained importance for the delivery of the drug in the colon because of their increase biocompatibility, controlled release of drug and higher stability. This review is discusses in brief about introduction to colon, Micro Carrier as colon drug delivery system. Oral delivery is still the most favorable route of drug administration, especially for chronic therapies where repeated administration of drug is required. Oral administration offers less pain, good patient convenience and reduced risk of cross infection and needle stick injuries.

There are various approaches for the delivery of therapeutic substance to the target site in a controlled release fashion. One such approach is using microspheres as carriers for drugs or active pharmaceutical compound. However, the success of this drug delivery system is limited due to their short residence time at the site of absorption. Mucoadhesive microspheres can be tailored to adhere to any mucosal tissue including those found in stomach, thus offering the possibilities of localized as well as systemic controlled release of drugs. This article presents the  advantages of Mucoadhesive microsphere, mechanism, theories involved in mucoadhesion, factor that affect the mucoadhesion, polymer in Mucoadhesive drug delivery system, methodology of preparation of Mucoadhesive microsphere, method of evaluation and their applications in drug delivery. Mucoadhesive drug delivery systems promises several advantages that arise from localization at a given target site, prolonged residence time at the site of drug absorption and an intensified contact with the mucosa increasing the drug concentration gradient.