RESUMO
Abstract This study aimed to develop promising and innovative mucoadhesive gel systems containing dexamethasone-loaded nanoparticle to increase the effectiveness of treatment for oral precancerous lesions and to reduce side effects. In this respect, a dexamethasone-loaded nanoparticle formulation was prepared by using emulsification/solvent evaporation method. The nanoparticle has high zeta potential (-10.3±0.5 mV), low particle size (218.42±2.1), low polydispersity index (0.070±0.014) and high encapsulation efficiency (95.018±2.982%). To improve the mucosal retention time, the dexamethasone-loaded nanoparticle was dispersed in mucoadhesive gel using gellan gum. The developed gels offered appropriate pH value, high drug content, suitable mechanical and mucoadhesive performance and appropriate viscosity for mucosal administration. All formulations exhibited plastic flow and typical gel-type mechanical spectra after the determined frequency value. The developed formulations exhibited extended drug release as intended for these systems. Cytotoxicity was tested by MTT assay in human epithelioid carcinoma cell (HeLa) in vitro. The MTT assay showed that the blank formulations were non-toxic to cells. It was observed that the bioactivity of the free dexamethasone was potentiated by mucoadhesive gels containing dexamethasone-loaded nanoparticle in HeLa cells. Results from this study indicate that mucoadhesive gels are effective for the local treatment of precancerous lesions. Our findings showed that the developed formulations were worthy of further studies.