A Novel Nanoemulgel Platform for the Topical Administration of Flecainide Acetate: A Strategy to Enhance Therapeutic Compliance in Arrhythmia Management.

Flecainide acetate is a potent antiarrhythmic agent with limited topical bioavailability due to physicochemical constraints. This study aimed to develop and evaluate a nanoemulsion-based topical gel of flecainide acetate to enhance drug solubility, stability, and sustained drug release. Preformulation studies, including organoleptic properties, melting point, solubility analysis, partition coefficient, and FT-IR spectroscopy, were conducted. Nanoemulsions were formulated using Captex 200 as the oil, Tween 80 as the surfactant, and PEG 400 as the co-surfactant based on pseudo-ternary phase diagrams. Optimized nanoemulsions were characterized by droplet size, zeta potential, viscosity, refractive index, pH, and in vitro diffusion studies. The optimized formulation was incorporated into a Carbopol 940 gel base and evaluated for its physicochemical properties, drug content, spreadability, in vitro release, and stability. The results demonstrated excellent stability, high drug release (91.23% at 12 h), and satisfactory physicochemical characteristics, indicating the potential of the nanoemulgel as an effective topical delivery system for flecainide acetate.