Formulation, Characterization, and Evaluation of Liposomal Antifungal Gel Co-Loaded With Lawsone and Amphotericin B for Topical Delivery

Objective: To formulate and evaluate a topical liposomal antifungal gel co-loaded with lawsone and amphotericin B (AmB) that aimed at providing improved drug delivery, sustained drug release, and reducing the toxicity of conventional AmB formulations. Methods: Lawsone and AmB-loaded liposomes were prepared by the thin-film hydration method and characterized for particle size, polydispersity index (PDI), zeta potential, entrapment efficiency, drug content, and in vitro drug release. Optimized liposomes were then added into a Carbopol 934 gel and evaluated for physicochemical characteristics, in vitro drug diffusion, release kinetics, and accelerated stability studies (30 °C/65% RH). Results: The optimized liposomes had a mean diameter of ~ 155 nm, PDI of 0.10-0.12, and zeta potential of −13.05 mV. The liposomal formulation showed entrapment efficiencies of 52% and 69%, with corresponding drug contents of 73% and 77% for lawsone and amphotericin B, respectively. The in vitro release study demonstrated a biphasic and sustained drug release over 24 h compared with the corresponding pure drugs and was best fitted to the Higuchi model for lawsone and the first-order kinetic model for AmB. The liposomal gel exhibited acceptable topical properties such as pH 6.89–7.19, viscosity 28,509±1,105 cP, spreadability 55 g•cm/s, and extrudability 79%±5.9. Drug diffusion at 12 h was 68.5% and 66.1%, respectively, for lawsone and AmB, and the results were found to follow non-Fickian diffusion kinetics by the Korsmeyer–Peppas model with R²>0.997. The formulation was physicochemically stable for 4 w. Conclusion: The developed lawsone-AmB liposomal gel demonstrated favorable physicochemical characteristics, sustained drug release, effective diffusion behavior, and good stability, indicating its potential as a promising topical antifungal delivery system.