Formulation development and evaluation of lidocaine hydrochloride loaded in chitosan-pectin-hyaluronic acid polyelectrolyte complex for dry socket treatment

The main purpose of this study was to assess a lidocaine hydrochloride-loaded chitosan-pectin-hyaluronic polyelectrolyte complex for rapid onset and sustained release in dry socket wound treatment. Nine formulations (LCs) of lidocaine hydrochloride (LH) loaded into a chitosan–pectin–hyaluronic polyelectrolyte complex (PEC) were assessed using full factorial design (two factors × three levels). The formulations ranged between 4 and 10% w/w LH and 0.5–1.5% w/w HA. The following physicochemical properties of LCs were characterized: size, zeta potential, % entrapment efficiency, viscosity, mucoadhesiveness, % drug release, morphology, storage stability, and cytotoxicity. The particle size, zeta potential, % EE, viscosity, and % mucoadhesion increased with increasing LH and HA concentrations. Rapid release of LH followed a zero-order model, and a steady-state percentage of the drug was released over 4 h. LCs were found to be non-cytotoxic compared to LH solution. LH loaded into PEC demonstrated appropriate characteristics—including suitable rate of release—and fit a zero-order model. Furthermore, it was not cytotoxic and showed good stability in a high-HA formula, making it a promising candidate for future topical oral formulations.