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

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 Reynoutria japonica 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 R. japonica 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.