MUCOADHESIVE MICROSPHERES AS INTRANASAL DRUG DELIVERY SYSTEMS: A REVIEW

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 residencetime at the site of application or absorption and facilitate intimate contact with the underlying absorptionsurface and thus contribute to improved and/or better therapeutic performance of drugs. Mucoadhesionis the process whereby synthetic and natural polymers adhere to mucosal surfaces in the body. If thesematerials 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, ingeneral, have the potential to be used for targeted and controlled release drug delivery; however, couplingof mucoadhesive properties to microspheres has additional advantages like a much more intimate contactwith the mucous layer, efficient absorption and enhanced bioavailability of the drugs due to a high surfaceto volume ratio. The present review describes the potential applications of mucoadhesive microspheresas a novel carrier system to improve nasal drug delivery for systemic or for local effects. The, methodsof preparation of microspheres and their in vitro and in vivo evaluation methods and the research workcarried out on these systems are also described.