ABSTRACT

Mucoadhesive polymers are the topic of current interest in the design of drug delivery systems. Mucoadhesive microspheres provide the means of improving drug delivery by promoting the residence time at the site of application or absorption and facilitate intimate contact with the underlying absorption surface and thus contribute to improved and/or better therapeutic performance of drugs. Mucoadhesion is the process whereby synthetic and natural polymers adhere to mucosal surfaces in the body. If these materials are then incorporated into pharmaceutical formulations, drug absorption by mucosal cells maybe enhanced or the drug may be released at the site for an extended period of time. Microspheres, in general, have the potential to be used for targeted and controlled release drug delivery; however, coupling of mucoadhesive properties to microspheres has additional advantages like a much more intimate contact with the mucous layer, efficient absorption and enhanced bioavailability of the drugs due to a high surface to volume ratio. The present review describes the potential applications of mucoadhesive microspheres as a novel carrier system to improve nasal drug delivery for systemic or for local effects. The, methods of preparation of microspheres and their in vitro and in vivo evaluation methods and the research work carried out on these systems are also described.