DESIGN, COMPARISON, AND EVALUATION OF LIDOCAINE HYDROCHLORIDE ORAL THIN FILMS USING NATURAL AND SYNTHETIC POLYMERS

Oral thin films (OTFs) have emerged as a promising alternative to conventional oral dosage forms due to their rapid disintegration, ease of administration, and improved patient compliance, particularly in pediatric and geriatric populations. The present study aimed to design, compare, and evaluate fast-dissolving oral thin films of Lidocaine Hydrochloride using natural and synthetic polymers. Lidocaine Hydrochloride, a widely used local anesthetic, was selected to achieve rapid onset of action and localized drug delivery in the oral cavity while bypassing first-pass metabolism. Oral thin films were prepared by the solvent casting method using hydroxypropyl methylcellulose (HPMC) as a synthetic polymer and sodium alginate as a natural polymer in different ratios. The prepared films were evaluated for physicochemical and mechanical properties including appearance, thickness, folding endurance, percentage elongation, surface pH, disintegration time, drug content uniformity, and in-vitro drug release. Preformulation studies confirmed the purity and compatibility of Lidocaine Hydrochloride with selected excipients. Among the various formulations, formulation F4 containing an optimized combination of HPMC (0.72 g) and sodium alginate (0.92 g) exhibited desirable mechanical strength, rapid disintegration, acceptable surface pH, and maximum drug release within a short duration. The study demonstrates that the combination of natural and synthetic polymers can effectively enhance film performance and drug release characteristics. Oral thin films of Lidocaine Hydrochloride prepared using optimized polymer combinations can serve as an efficient, patient-friendly dosage form for rapid local anesthetic action.