Physicochemical and in vitro mucoadhesive properties of microparticles/discs of betamethasone for the management of oral lichen planus.

This study involved the preparation and evaluation of buccal-mucoadhesive microparticles/discs of bethamethasone disodium phosphate (BDSP). The microparticles were prepared using the emulsion solvent diffusion method. Microparticles were prepared and characterized by encapsulation efficiency particle size, Fourier Transform Infra Red (FTIR) spectrums, Differential Scanning Calorimetric (DSC) thermograms and mucoadhesive properties. FTIR studies reported that BDSP was changed to bethamethasone base molecule inside the intact microparticles. The best drug to polymers ratio in microparticles was F containing 50 mg drug, 50 mg HPMC (as non-ionic and hydrophilic polymer) and 50 mg carbomer 934p (an anionic mucoadhesive polymer). The production yield of F1 microparticles was calculated as 78.60% with loading efficiency of about 65.14% and the mean particle size was also measured as 281.84 μm. It was proposed that during the microparticle preparation procedure, water soluble salt of the drug may be converted to the base which could be more effective in the buccal mucosa due to its higher partition coefficient and lipophilicity. The highest and lowest releases resulted from the discs prepared from F and F, respectively, compared with the commercial tablet and untreated drug powder (p < 0.05). The data revealed that the discs exhibited good percentage of mucoadhesion (F, 326 g/cm). It may be concluded that drug loaded buccal-mucoadhesive microparticles are a suitable delivery system for BDSP, and may be used in the effective management of lichen planus.