Herbal buccal films with in vitro antibacterial and anti-inflammatory effects

In recent years, natural products have been studied as antimicrobial agents and as compounds to develop phytomedicines. Although they are also useful to treat buccal infections, the oral cavity has characteristics that impair the development of topical buccal pharmaceuticals. Thus, the aim of this work was to develop buccal films, including a combination of Lippia turbinata and Lippia alba extracts, with anti-inflammatory and antibacterial activity, pleasant organoleptic characteristics, mucoadhesive capacity, good mechanical properties and ability to not quickly dissolve in the oral cavity. Firstly, the extracts were characterized by their phenolic profile (HPLC-PDA-ESI-MS/MS), and antibacterial (broth microdilution and checkerboard assays) and anti-inflammatory (in vitro LOX inhibitory activity) activities. The films were produced using the solvent casting method. The film-forming polymers were hydroxypropylmethylcellulose alone and hydroxypropylmethylcellulose combined with Eudragit® polymers. The films were characterized by their physico-chemical properties, color, mucoadhesiveness, mechanical properties, release profile, and permeation performance. The main polyphenolic components found in the extracts were flavones. The combination of extracts improved the antibacterial and anti-inflammatory activities. All films presented acceptable organoleptic characteristics. The chromatic values were those expected for plant extracts and the appearance of superface varied according to the polymers used. The inclusion of Eudragit® in the formulations modified their microstructure, giving them elasticity, increasing their swelling index and release rate, and accelerating the permeation of polyphenols in the porcine oral mucosa. The characteristics of the films evaluated were acceptable for use. In addition, the P3 film presented better mucoadhesion, which makes it more appropriate for oral application.