Nanoemulsion-Based Tea Tree Oil: A New Frontier in Enhancing Clotrimazole Antifungal Activity

Clotrimazole is widely used to treat fungal diseases, but it should be applied topically for several weeks to be effective. Previous studies have shown that nanoemulsions can enhance the topical activity of various active ingredients. This study aimed to prepare a nanoformulation of clotrimazole to improve its antifungal activity. A nanoemulsion containing clotrimazole was prepared using Tween 80 and Tween 20. The particle size was measured using Dynamic Light Scattering (DLS) and Transmission Electron Microscopy (TEM). Stability studies were conducted using freeze-thaw cycles and storage at 40 °C. The antifungal activity of clotrimazole was then compared with bulk clotrimazole both in vitro and in vivo. The nanoemulsion containing clotrimazole had a particle size of 31.5 nm, measured by DLS and remained physically stable after 1 year of storage. In vitro antifungal studies showed that this nanoemulsion outperformed both bulk clotrimazole and the nanoemulsion without clotrimazole, with MIC values of 1/524288, 1/8192, and 1/1024, respectively, against T. mentagrophytes. In addition, animal studies demonstrated that mean (SD) treatment time for fungal infection was 8.6 (0.5) days with the nanoemulsion containing 1% clotrimazole, significantly smaller than that of bulk clotrimazole (1% w/w) and nanoemulsion without clotrimazole (i.e., 15.0 (1.6) and 20.0 (0.7) days, respectively). The treatment time was more than 21 days for the bulk tea tree oil and the untreated control. After 21 days of treatment, only animals treated with the clotrimazole nanoemulsion showed complete lesion healing and weight changes comparable to healthy animals. The nanoemulsion formulation containing clotrimazole demonstrates highly desirable antifungal properties, warranting further investigation in clinical trials.