Tailoring thixotropic mixed-lipid nanoconstructs of voriconazole for the management of Vulvovaginal candidiasis: Formulation, statistical optimization, in vitro characterization and in vivo assessment

Abstract

Vulvovaginal candidiasis is a pervasive gynecological condition among women worldwide due to infection recurrence and resistance to conventional drugs. This calls for a novel formulation of alternative medication and with enhanced efficacy. This study aimed to fabricate mixed-lipid nanoconstructs (MLNCs) of voriconazole (VCZ) with a low concentration of lipids applying high shear homogenization and ultrasonication to form a semisolid formulation. Tefose 63 and Gelot 64 were employed as emulsifiers that are specified for vaginal preparations; as per their mucoadhesive properties and their texture enhancing characters, although usually used as lipids in different lipid carriers. A 24 factorial design was established and the optimized formulation was prepared using 10% total lipids, in which solid lipids (Sterotex NF: Glyceryl monostearate) ratio was 1.92:1 and the oils percentage was 30% (Maisine: Glyceryl monooleate, in the ratio of 1:1), and the emulsifiers mixture (Tefose 63: Gelot 64) ratio was 1:1, as 10% of total formulation weight. The optimized formulation with a viscosity of 964.49 ± 57.99 cp showed spherical nanoparticles (322.72 ± 15.11 nm) that entrapped 67.16 ± 3.45% of VCZ and exhibited release of 70.08 ± 2.87% in 8 h. The optimized formulation with high bioadhesive potentials significantly reduced the fungal burden in female Wistar rats infected with vaginal candidiasis, compared to the aqueous VCZ suspension (p < .05). Furthermore, in vivo histopathological findings proved the effectiveness and the safety of the optimized MLNCs formulation after vaginal application. Inclusively, MLNCs formulation could be a promising vaginal delivery system of VCZ for the treatment of vulvovaginal candidiasis.