From the waste of must clarification to the production of a high polyphenols’ rich buccal film: new insight to treat oral oxidative stress-related pathologies

Introduction: To support drugs’ treatment of oral oxidative stress-related patologies polyphenols can be ideal candidates due to their antioxidant and antinflammatory activities1. A liquid polyphenols’ enriched excipient could be obtained by virtuous recovery of waste black bentonite (BB) coming from white grape must filtration2. Material & Methods: Both the BB-wet (starting waste as supplied) and BB-dry (after freeze-drying) were subjected to 7 consecutive cycles of green extraction by maceration with PEG200 as unconventional and innovative green solvent.The extracts were characterized by HPLC-DAD analysis, Folin-Ciocalteu, Bradford and DPPH assays. A thin buccal film was prepared by solvent casting using pectin as matrix polymer, calcium lactate and the best extract. Results: The multiple maceration procedure greatly enrich PEG200 in polyphenols. The best product was obtained from the BB-wet (third extraction step) and resulted in a solvent recovery >40% and GAE ≈ 4 mg/g. Consequently, it was directly used to prepare a soft, deformable and homogeneo buccal film. Conclusion: The valorization of the waste BB could be a virtuous approach to recover polyphenols. The consecutive multiple green maceration process produced a highly polyphenols’ rich secondary raw material directly useful to produce buccal films potentially promising to locally treat several oxidative stress-related oral pathologies.