Biopolymeric films based on chitosan and copaiba oleoresin: preliminary insights for oral applications

Abstract

Polymeric films for oral applications remain underexplored, despite their potential as multifunctional therapeutic systems. Effective oral dressings must adhere to mucosal surfaces, promote tissue repair, reduce microbial proliferation, and protect injured areas. This study focused on the formulation and characterization of bioactive films composed of chitosan (CH) and copaiba oleoresin (COR) at varying concentrations (0.5%, 1%, and 3.5%), selected based on prior research. The films were obtained by solvent evaporation and evaluated for their physicochemical, morphological, and biological properties. Spectroscopic analyses (Raman and FT-IR) revealed molecular interactions between CH, COR, and excipients, with significant spectral shifts in functional groups, particularly from malic acid and glycerin, indicating successful incorporation.The films exhibited a moisture content ranging from 15.24% to 20.23%, which decreased with higher COR concentrations due to their hydrophobic nature. While all formulations demonstrated high swelling capacity and solubility, increased COR content reduced water absorption, suggesting a concentration-dependent modulation of film hydrophobicity. Given these findings, no single formulation emerged as universally optimal; instead, the selection of COR concentration should align with specific therapeutic goals, such as rapid bioactive release or prolonged mucosal adhesion. These results highlight the potential of CH–COR films as promising candidates for the topical treatment of oral mucosal lesions. Future research should focus on optimizing film composition to enhance antimicrobial efficacy while maintaining mechanical stability, paving the way for clinical applications.