High Value-Added Secondary Raw Material From Winemaking Waste Bentonite to Design Antioxidant Pectin-Based Mucoadhesive Buccal Films

Buccal films are versatile formulations providing targeted drug delivery while ensuring patient comfort, easy administration, and improved efficacy. Additionally, they act as wound dressings, making them suitable to treat painful oral lesions associated with conditions such as oral mucositis, oral lichen planus, and recurrent aphthous stomatitis. Considering the oxidative stress-related nature of these disorders, natural antioxidants as polyphenols represent promising candidates for locoregional therapy. The aims of this work were to enhance polyphenols recovery from waste bentonite, a wine industry by-product, to obtain a sustainable high value-added secondary raw material, and to directly exploit it for buccal film formulation. Polyphenols recovery was maximized through a multiple extraction process using PEG200 as solvent. By investigating both dry and wet matrices and different agitation methods, the impact of water in the original waste and the importance of waste solvent mixing were highlighted. The best balance between extraction efficiency and cost-effectiveness was identified and the selected extract, named Bentophen200, was used to produce buccal films based on citrus pectin alone (BentoPect) or combined with hyaluronic acid (BentoPect-Hyalu) by green solvent casting. Showing lower swelling, stronger mucoadhesion, and greater mucosal polyphenols accumulation, BentoPect emerged as potential therapeutic agent for prolonged mucosal contact and pain relief.