oralmucoadhesive paste of triamcinolone acetonide and zinc sulfate: preparation and in vitro physicochemical characterization

aphthous stomatitis and oral lichen planus may be found on mucosal surfaces including the gingival, tongue and lips. these conditions frequently require topical corticosteroid medication such as triamcinolone acetonide (ta). recently, studies showed that divalent inorganic salts such as zinc sulphate (znso 4 ) are recommended for treatment of aphthouse, herpes ulcers and other ulcers in the body. in this study we developed orabase formulation of znso 4 0.25% and ta 0.1% that is suggested tohavesynergistic effect on ulcer treatment. to achieve this goal, different ratio of bioadhesive polymers such as pectin, gelatin, nacmc and plastibase wereused and the effects of these factors was evaluated on physicochemical properties of the pastes.the in vitro bioadhesive strength, spreadability test and occlusivity strength properties of the orabase were investigated using new designed device, while swelling behavior was studied in different media, namely, distilled water and simulated salvia solution. ta and znso 4 concentration were determined using hplc and voltammetry system, respectively. the in vitro drug release was investigated in phosphate buffer (ph=7) at 37°c by franz diffusion cell. the optimum formulation showed that the increase in nacmc content and decrease in water content were found to elevate the bioadhesive and occlusivity strength. also decrease in nacmc content was found to elevate the drug release rate. optimum formulation had adhesion strength equal to 131.948 mn/cm 2 , spreadability equal to 0.067 cm, percent of occlusivity strength equal to 53.3% and a swelling index very similar to brand sample (adcortyl0.1%) in both the distilled water and phosphate buffer.we canclaim that optimum formulation is comparable to brand sample and we suggest that it is a promising and suitable carrier for transmucosal drug delivery system.