Use of novasomes as a vesicular carrier for improving the topical delivery of terconazole: In vitro characterization, in vivo assessment and exploratory clinical experimentation

Abstract

Purpose: This manuscript aimed at encapsulating an antifungal terconazole (TCZ) into innovative novasomes for improving its penetration into the skin and clinically modulating its therapeutic efficacy. Methods: Novasomes containing free fatty acid (FFA) as a penetration enhancer were formulated using ethanol injection technique based on 24 full factorial design to explore the impact of various formulation variables on novasomes characteristics regarding entrapment efficiency percent (EE%), particle size (PS), polydispersity index (PDI), and zeta potential (ZP). The optimum formulation was chosen using Design-Expert® software and utilized for further explorations. Results: The chosen formulation (N15; including 100 mg lipid components and Span 80 to oleic acid in a ratio of 2:1 (w/w)) exhibited an EE% = 99.45 ± 0.78%, PS = 623.00 ± 2.97 nm, PDI = 0.40 ± 0.04, and ZP = −73.85 ± 0.64 mV. N15 showed spherical vesicles with a higher deformability index (DI) (9.62 ± 0.15 g) compared to traditional niosomal formulation (0.92 ± 0.12 g). Further, N15 showed superior inhibition of Candida albicans growth relative to TCZ suspension using XTT (2,3-bis-(2-methyloxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) reduction assay. Moreover, in vivo skin deposition tests revealed a superior TCZ deposition inside the skin from N15 in comparison to traditional niosomal formulation and TCZ suspension. Furthermore, histopathological examination for rats assured the safety of N15 for topical use. A clinical study conducted on infants suffering from napkin candidiasis proved the superiority of N15 to placebo in providing a complete cure of such fungal infections. Conclusion: Concisely, the obtained outcomes confirmed the pronounced efficacy of N15 to successfully treat skin fungal infections.