Optimization of Cellulose Derivative-, PVA-, and PVP-Based Films with Reynoutria japonica Extract to Improve Periodontal Disease Treatment

The aim of this study was to develop and optimize polymeric films based on cellulose derivatives-hydroxypropylmethylcellulose (HPMC), methylcellulose (MC), and sodium carboxymethylcellulose (NaCMC)-as well as pullulan, polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), and glycerol (GLY) as plasticizer incorporating <i>Reynoutria japonica</i> extract for potential use in periodontal and gum disease treatment. Over 80 formulations were fabricated using the solvent-casting method, 6 of which were selected for further investigation based on their mechanical properties, mucoadhesion, and disintegration profiles, including three placebo films (OP1 (PVA/PVP/MC400CP/NaCMC/GLY), OP2 (PVA/PVP/MCA15C/NaCMC/GLY), and OP3 (PVA/PVP/HPMC/NaCMC/GLY)) and three films containing <i>R. japonica</i> extract (OW1, OW2, and OW3). The films demonstrated uniform structural characteristics, with the formulations containing PVA with a high hydrolysis degree (98-99%) and methylcellulose derivatives showing prolonged dissolution times due to physical cross-linking, while the inclusion of NaCMC reduced dissolution time without compromising mucoadhesiveness. The study also described the release kinetics of resveratrol and piceid from the OW2 films using three semi-empirical models: the Korsmeyer-Peppas model, a first-order kinetic model, and a multidimensional approach. The multidimensional model demonstrated a strong fit, with a correlation coefficient (R²) of 0.909 for resveratrol, compared to 0.894 and 0.908 for the Korsmeyer-Peppas and first-order models, respectively. For piceid, the multidimensional model showed a correlation coefficient (R²) of 0.958, outperforming the Korsmeyer-Peppas (0.823) and first-order models (0.932). The active compounds released in sustained-release tests, including resveratrol and piceid, suggest that these films could provide an extended therapeutic effect.