In vivo vaginal fungal load reduction after treatment with itraconazole-loaded polycaprolactone-nanoparticle

Abstract

Itraconazole (ITZ) has a broad spectrum of action and is commonly used for the treatment of fungal infections. Topic administration of ITZ is a promising strategy to improve vulvovaginal candidiasis treatment, which can be further optimized by its encapsulation in nanoparticles to increase drug delivery and reduce ITZ toxicity. In this work, we designed polycaprolactone nanoparticles containing ITZ and evaluated in vivo the efficacy of this yet unexplored approach. Nanocapsules (ITZ-NC) and nanospheres (ITZ-NS) were obtained by nanoprecipitation. ITZ-NC presented encapsulation efficiency of 99%, mean diameter of 190 nm, PDI 0.1 and zeta potential of –15 mV. ITZ-NS showed encapsulation efficiency of 97%, mean diameter of 120 nm, PDI 0.1 and zeta potential of –10 mV. Both particles were efficiently freeze-dried using 10% trehalose + 10% sucrose. Nanoparticles were then incorporated in a viscous formulation for vaginal application in female Balb/C mice infected with Candida albicans. Fungal load was significantly reduced in infected animals after treatment with ITZ-NC but not with ITZ-NS, compared to animals treated with ITZ solution. Histological analysis showed a clear difference between vaginal tissues of ITZ-NC and ITZ-NS and ITZ solution-treated animals, which correlated with IL-1β and TNF-α quantification. Animals treated with ITZ-NC showed reduced cytokine levels and healthy tissue characteristics, while animals treated with ITZ-NS and ITZ solution showed increased IL-1β and TNF-α levels and typical tissue inflammation. Our results demonstrate the potential of ITZ-NC to improve the treatment of vulvovaginal candidiasis after topical application in the vagina, opening new perspectives for the treatment of this disease.