Development of Mucoadhesive Film-Forming Systems Containing Black Ginger Extract for Aphthous Ulcers

Film-forming systems (FFSs) were developed by using Eudragit® E100 as a film former. Kaempferia parviflora (black ginger) extract was used as an anti-inflammatory agent for aphthous ulcers. The FFS could rapidly form a thin film in only 5 s when it was applied to a wet surface e.g. an aphthous ulcer. When the FFS was applied to a dry surface, the FFS without extract could form a film in 2-4 min. The incorporation of this extract contributed to delaying the film-formation time in the dry state; hence, the film-forming time increased to 6-8 min. The mucoadhesive property of FFSs was verified with the wash-off method. To simulate oromucosal conditions, the FFSs were applied on a cellophane membrane coated with mucin and washed by phosphate buffer of pH 6.8. The formulations without mucoadhesive polymers could not withstand flushing with a medium for more than 8 min without dislodging. Therefore, three different mucoadhesive agents were trialed: PVP K90, HPMC E15 LV, and HPC SL. The highest adhesion results were obtained when HPMC was added at 5%(w/w) as well as, the residence time was 22 min. In vitro release of black ginger extract from FFS showed a gradual release for 2 h. This study indicated that the FFS with HPMC E15 LV was an appropriate alternative formulation as a local delivery system for an aphthous ulcer.