Innovative simvastatin-loaded emulgel effectively treats vulvovaginal candidiasis: in vivo efficacy and in vitro biopharmaceutical analysis.

We evaluated the pre-clinical efficacy of simvastatin (SVT)-loaded emulgels in an in vivo model of azole-resistant Candida albicans (ATCC 10231)-induced vaginal candidiasis and conducted in vitro biopharmaceutical characterization of the most effective formulation. The efficacy of SVT-loaded emulgels (15, 30, and 60 mg/g) was assessed in immunosuppressed Wistar rats with induced candidiasis and compared to commercially available vaginal creams containing clotrimazole (10 mg/g) or nystatin (25,000 IU/g). Products were administered once daily for seven days (n = 5 per group). A high-resolution and sensitive HPLC-PDA method was developed and validated to quantify SVT, determine its solubility in the release medium, and evaluate its in vitro release profile and kinetics. The 60 mg/g SVT-loaded emulgel achieved a 100% reduction in fungal load after 7 days (p < 0.05). SVT solubility in the release medium was 881 ± 36 µg/mL, and its content in the emulgel was 114.95 ± 4.46% m/m. The controlled release kinetics followed Makoid-Banakar's model, indicating an average release rate of 0.036%/h. Therefore, the 60 mg/g SVT-loaded emulgel shows potential as a therapeutic strategy for treating resistant vulvovaginal candidiasis, warranting further clinical studies.