Fingerroot Extract Oral Spray for Anticariogenic Purpose: Integration of Ultrasound-Assisted Extraction and Solvent System Optimization.

Fingerroot (Boesenbergia rotunda (L.) Mansf.), a member of the Zingiberaceae family, exhibits anticariogenic activity against Streptococcus mutans. This study aimed to optimize ultrasound-assisted extraction and solvent system selection for oral spray development. Extraction conditions were optimized using a Box-Behnken design, evaluating ultrasonication time, solvent-to-solid ratio, and ethanol concentration. The optimal conditions-45-min ultrasonication, 30:1 solvent-to-solid ratio, and 85% ethanol-yielded the highest contents of pinocembrin, pinostrobin, and panduratin A. The optimized extract was then subjected to solvent system optimization using an I-optimal design to identify combinations of water, polyethylene glycol 400, and 95% ethanol for effective flavonoid recovery and solubilization. Three solvent systems (12:13:75, 10:30:60, and 6:60:34) were selected for oral spray formulation. Each formulation contained 0.03% sucralose, 0.3% menthol, 0.02% sodium methylparaben, and 0.18% sodium propylparaben. The resulting sprays demonstrated anticariogenic activity against S. mutans. Stability studies showed a decline in pH and flavonoid content over time, whereas viscosity and antimicrobial activity remained stable, as evidenced by inhibition zones. In summary, this study successfully combined extraction and solubilization optimization strategies to develop a fingerroot oral spray with potential anticariogenic properties.