Microemulsion-Based Gels: A Hybrid Platform for Enhanced Anti-fungal Therapeutic Delivery

Superficial skin infections caused by fungi are common across the world and involve the stratum corneum or the outer skin layer which is rich in keratin and provides a favorable environment for fungal growth. Topical drug delivery is the preferred approach for managing such infections. However, conventional topical dosage forms, including creams and gel generally have drawbacks such as poor solubility of lipophilic antifungal agents, limited penetration across the skin barrier and low therapeutic performance. In recent years, microemulsion-based gel formulations have gained attention as an advanced strategy for topical antifungal delivery due to their ability to overcome these limitations. Microemulsions exhibit isotropic properties and thermodynamic stability consisting of oil, water, surfactants, and co-surfactants. These systems facilitate improved drug solubilization, enhance penetration through the stratum corneum and promote long-term retention of the drug at the site of infection. This review presents a detailed discussion of the formulation aspects, structural features and mechanisms of action of topical antifungal microemulsions, with special focus on azole-based drugs. Various methods employed in their preparation, such as phase titration and phase inversion techniques, are described, along with the importance of pseudo-ternary phase diagrams in optimizing formulation composition. In addition, previously published studies on microemulsion-based antifungal gels are also reviewed to emphasize their therapeutic effectiveness. Overall, microemulsion-loaded topical gels offer a flexible and efficient delivery platform, demonstrating enhanced clinical performance and considerable potential for future pharmaceutical development