Microspheres: Mucoadhesion Based Controlled Drug Delivery System

A well designed controlled drug delivery system can overcome several problems of conventional therapy and also enhance the therapeutic effi cacy of active pharmaceutical compounds. 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. Thus, mucoadhesion characteristics are coupled to microspheres to develop a novel delivery system referred to as “mucoadhesive microspheres”. These mucoadhesive carriers provide an intimate contact with the mucus layer and specifi c targeting of drugs to the absorption site. In recent years, mucoadhesive microspheres have been developed for oral, buccal, nasal, ocular, rectal and vaginal for either systemic or local effects. Present work highlights the numerous aspects of microspheres i.e. method of preparation, delivery route, various polymers used for preparation and applications. Moreover, recent patents granted till now are also discussed in detail.