Topical Miconazole Nanogel: In Vitro Characterization, In Vivo Skin Irritation, and Enhanced Antifungal Efficacy

This study focused on the development of a miconazole nanogel formulation. The nanogel was prepared using the solvent diffusion method (high-speed homogenization) with Carbopol 940/chitosan/locust bean gum (Different gelling agents were used) and triethanolamine. The formulation was thoroughly evaluated for various physicochemical properties, including appearance, pH, FTIR analysis, viscosity, washability, spreadability, extrudability, drug content, entrapment efficiency, particle size, zeta potential, optical microscopy, differential scanning calorimetry (DSC), skin irritation, ex-vivo skin penetration, in-vitro diffusion, in-vitro antifungal activity, and stability. The prepared nanogel exhibited a clear, homogenous, white appearance with a pH compatible to skin pH (5.4-6.2). FTIR analysis confirmed the compatibility between the drug and polymers. The nanogel demonstrated good viscosity (3239-4175 cps), washability, and spreadability (2.5-3.5). Extrudability studies revealed easy extrusion of the formulation. Drug content ranged from 90.15% to 99.36%, with entrapment efficiency between 78.85% and 95.00%. The nanogel had a particle size of 534 nm and a zeta potential of -37.7 mV. Microscopic analysis showed spherical nanoparticles. DSC analysis indicated no change in the melting point of miconazole, which is one of the characteristics that confirm the stability of the drug with excipients. Skin irritation studies on rats revealed no erythema or edema after 24 h. In-vitro drug release ranged from 86.12% to 99.00%. Ex-vivo skin penetration and retention were higher for the nanogel than the marketed gel. In-vitro antifungal studies demonstrated superior activity of the nanogel compared to the marketed and standard formulations. Stability studies revealed no significant changes in drug content, extrudability, spreadability, pH, or in-vitro drug release. The developed miconazole nanogel formulation exhibited promising characteristics, including controlled drug release, enhanced skin penetration, and antifungal activity. It represents a potential advancement in topical antifungal therapy.