Formulation, Optimization and Evaluation of topical Niosomal Gel for Oxiconazole

Niosomes are novel vesicular drug-delivery systems that can improve drug entrapment, provide controlled drug release, and prolong drug residence at the site of application. Oxiconazole nitrate is a broad-spectrum imidazole antifungal agent used for the treatment of superficial fungal infections. However, conventional topical formulations may have limited residence time The objectives of the present study were to develop an ideal drugdelivery system for the effective treatment of fungal infections, maintain the therapeutic drug concentration for an appropriate period, enhance patient compliance, and improve the therapeutic effectiveness of the formulation. The study also aimed to reduce adverse effects and enhance the bioavailability of the drug. Furthermore, the study focused on formulating a novel drug-delivery system using an appropriate formulation technique and evaluating the developed formulation through SEM analysis, drug content, entrapment efficiency, and in-vitro drug-release studies. Finally, stability studies were performed to assess the physical and pharmaceutical stability of the optimized formulation. Oxiconazole-loaded niosomes were prepared by the ether injection method using Tween 80 and cholesterol. A Box–Behnken design was employed using cholesterol concentration, Tween 80 concentration, and stirring speed as independent variables. Particle size, zeta potential, and entrapment efficiency were selected as responses. The optimized niosomes were incorporated into a Carbopol 937-based gel and further optimized using Box–Behnken design, with Carbopol 937 concentration, Tween 80 concentration, and stirring speed as independent variables. The optimized formulations were evaluated for drug content, pH, viscosity, spreadability, extrudability, gel strength, gelling capacity, in-vitro drug release, FTIR, DSC, XRD, SEM, and stability. The optimized niosomal formulation (NO10) exhibited a particle size of 224.7 nm, zeta potential of −26.5 mV, and drug content of 86.42%. NO10 demonstrated 96.82% cumulative drug release at 8 h. The optimized niosomes were successfully incorporated into the topical gel. The optimized gel formulation (OG9) showed a pH of 4.96, spreadability of 6.64 g·cm/s, and 94.96% cumulative drug release at 8 h. XRD analysis indicated predominantly amorphous characteristics of the encapsulated drug. During three months of stability evaluation, only minor changes were observed in pH, spreadability, and drug release. The developed oxiconazoleloaded niosomal gel exhibited favorable physicochemical characteristics and sustained drug-release behavior. The optimized formulation demonstrated satisfactory stability and may serve as a promising novel topical drugdelivery system for oxiconazole.