Formulation, Development, and In vitro Evaluation of Sustained Release Buccal Films for Optimized Memantine Therapy.

Abstract

Introduction: Memantine, an N-methyl-D-aspartate (NMDA) receptor antagonist, is employed in moderate to severe Alzheimer's disease but has the disadvantage of low oral bioavailability owing to first-pass metabolism and multiple doses. Buccal drug delivery is one such alternative that has received attention for enhancing systemic availability and patient compliance.

Methods: Sustained-release buccal films of memantine hydrochloride were prepared by the solvent casting technique using Hydroxypropyl Methylcellulose (HPMC) and Carbopol 940 as film-forming and mucoadhesive polymers, polyethylene glycol 400 as plasticizer, and menthol as permeation enhancer. UV and FTIR were used for preformulation studies and for compatibility testing. The films were assessed for their physicochemical properties, tensile strength, swelling studies, surface pH, drug content, residence time, and in vitro release. Optimization of the result was carried out by statistical regression analysis with Design Expert® software.

Results: The prepared films possessed uniform thickness, good mechanical properties, surface pH compatible with the buccal mucosa, and provided constant drug release for 8 h. FTIR studies revealed that there was no chemical incompatibility between memantine and excipients. F11 was found to have the highest drug content (90.1%), a good swelling index (19.4%), good folding endurance, and a conducive residence time of approximately 5 h.

Discussion: The sustained release and the positive mucoadhesive properties observed are in line with those reported for other buccal film systems. The swelling profile and drug release kinetics were markedly affected by the polymer concentration.

Conclusion: The developed sustained-release buccal films of memantine hydrochloride demonstrated favorable physicochemical and in vitro release characteristics, indicating their potential as a noninvasive alternative drug delivery system. Although buccal administration is theoretically capable of bypassing hepatic first-pass metabolism and improving systemic availability, such benefits could not be conclusively established in the absence of in vivo pharmacokinetic and ex vivo permeation studies. Therefore, further investigations are required to validate these potential advantages.