Solubility-Enhanced α‑Mangostin Bilayer Films: Synergizing Mucoadhesion and Protection for Effective Aphthous Ulcer...

Aphthous ulcers are prevalent and painful oral mucosal lesions that substantially compromise patient quality of life, requiring effective localized treatment. α-Mangostin, a bioactive compound from mangosteen pericarp, exhibits potent anti-inflammatory properties but suffers from poor aqueous solubility. This study developed a double-layer mucoadhesive film incorporating an α-mangostin-based solid dispersion (MPESD) to enhance solubility and provide dual-functionality: protection and therapy. Mangosteen peel extract was formulated into solid dispersions using PVP K30, significantly enhancing solubility from undetectable levels to 8.12 ± 0.04 mg/mL (1:4 ratio). The films, comprising an ethylcellulose backing layer and a gelatin-HPMC mucoadhesive layer, were fabricated via solvent casting. Mechanical testing confirmed suitable puncture strength (1.63 N/mm²) and flexibility (20% elongation) for oral application. The inclusion of HPMC improved surface wettability and prolonged in vitro residence time to >8 h, while the optimized film achieved 96% drug release within 2 h. These findings demonstrate that the MPESD-loaded double-layer film presents a promising formulation strategy with the potential for managing aphthous ulcers.