REVIEW ON MUCOADHESIVE DRUG DELIVERY SYSTEMS

This review considers the basic mechanisms by which mucoadhesive can adhere to a mucous membrane in terms of the nature of the adhering surfaces and the forces that may be generated to secure them together.it also include contact stage and consolidation stage. Mucosal adhesion is backed by several theories. Much attention has been focused in the field of mucoadhesive formulation developments compared to other delivery systems. Mucoadhesion while considering drug delivery is having several merits, because of the ideal physiochemical characters of the mucosal membrane. Ideally a mucoadhesive dosage form interacts with the mucosal membrane by ionic bonds, covalent bonds, Van-der-Waal bonds and hydrogen bonds. Various sites for mucoadhesive drug delivery system are ocular, nasal, buccal cavity; GIT, vaginal, rectal and several specific dosage forms have been reported. Factors affecting mucoadhesion are molecular weight, flexibility of polymer chain, pH, presence of carboxylate group and density. Several synthetic and natural polymers are identified as suitable candidates for mucoadhesive formulation. Ex-vivo/in-vitro studies utilizing gut sac of rats provides in-depth knowledge about the adhesive property of the dosage form as well as polymers. AFM can be used as a part of imaging methods. Mucoadhesive drug delivery system shows promising future in enhancing the bioavailability and specific needs by utilizing the physiochemical characters of both the dosage form and the mucosal lining. It has to be noted that only a moist surface can bring the mucoadhesive nature of the dosage form.