Development and evaluation of muco-adhesive buccal films containing metronidazole for the treatment of periodontal diseases

Gingivitis, a reversible inflammation of the gums leads to an advancement to periodontitis, a more severe and often irreversible stage characterized by the destruction of connective tissue and bone, potentially leading to tooth loss.This study was designed to develop and evaluate muco-adhesive buccal films containing metronidazole for localized treatment of periodontal disease, aiming to reduce systemic side effects and improve therapeutic efficacy. Thin films were prepared using chitosan as the primary polymer, combined with various copolymers (HPMC, MC, EC, PVP, HPC, and Carbopol) via the solvent casting technique. Thirteen formulations (F1-F13) were investigated for their ability to control the in vitro drug release, surface pH, folding endurance, drug content uniformity, and muco-adhesion, in addition to studying drug release kinetics. Formulations F12 (60.0% HPMC, 20.0% chitosan) and F13 (20.0% HPMC, 60.0% chitosan) showed optimal surface pH (≈6.7-7.0) with high muco-adhesion characteristics (49-51 Mn/m). Sustaining or expediting the drug release rate was manipulated by tailoring the polymer composition within the studied formulations. Examining drug release data has shown that the release kinetics followed the Korsmeyer-Peppas model, indicating diffusion and polymer relaxation mechanisms. The study demonstrates that polymer selection, in addition to the chosen ratio allows customization of release kinetics, Formulation F9 (20.0% HPC, 60.0% Chitosan) was proven to have the ability to provide the most sustained release characteristics. These findings support the potential of chitosan-based muco-adhesive films as effective localized delivery systems for metronidazole in periodontal therapy.