CHARACTERSTIC FEATURES OF POLYMERS USED IN MUCOADHESIVE BUCCAL DELIVERY
The histological features of buccal mucosa makes it feasible site for sustained release delivery system which could maintain steady release of drug in systemic. Various delivery approaches have been developed to deliver drugs into oral cavity for either oral or systemic action. The simplest and oldest dosage forms are lozenges and mouthwashes. The drug is constantly washed away by a considerable amount of saliva from these non-attached delivery systems resulting into initial burst effect followed by a rapid decrease in concentrations to below therapeutic levels. By the interfacial forces and bond formation of mucoadhesive polymers to extend the contact with the mucous surface for achieve the therapeutic effect. Different mechanism in which the dosage form can achieve the desired effect on the site of action is spreading, wetting and dissolution of mucoadhesive polymer on the interface, followed by mechanical or physical entanglement between the polymer and mucus results in inter penetration layer which leads to chemical interaction such as covalent and ionic bonds, hydrogen bonding and vander waalâ€s interaction. From the all the above mechanism the hydrogen bond and hydrophobic interactions are most desirable for mucoadhesive system