The main objective of the present study was to formulate and evaluate mucoadhesive in situ buccal gels of dexamethasone based on gellan gum-poloxamer 407. Formulations were characterized for gelling capacity, drug content, pH, viscosity, rheological studies, mechanical studies and in vitro drug release. The drug content, clarity and pH of the formulations were found to be satisfactory. Mucoadhesive in situ gels showed thermoresponsive behavior, existing as a liquid at room temperature and gel at 30-37 degrees C. Formulations exhibited pseudoplastic flow and typical gel-type mechanical spectra (G' > G '') at different frequecy values and 37 degrees C. Prepared gels resulted in preparations with desirable rheological features as well as texture (appropriate hardness, compressibility, adhesiveness, cohesiveness and elasticity) properties, which could benefit the therapeutic efficacy, by increasing the residence time and easiness for local application on the buccal mucosa. Additionally, the developed preparations exhibited sustained drug release up to 72 has intended for these systems. Optimized formulation containing 14% w/v poloxamer 407 and 0.4% w/v gellan gum exhibited desired characteristics (mechanical and rheological properties) for developing buccal drug delivery systems. Thus, buccal dexamethasone loaded mucoadhesive in situ gel was found to be a promising formulation.