Eberconazole nitrate–loaded spanlastics: nanocarriers for topical delivery system

Abstract

Eberconazole nitrate (EBN), a broad-spectrum imidazole antifungal agent, is widely used for the topical treatment of fungal mycoses. However, as a BCS class II drug, EBN faces problems such as poor skin permeability and low cutaneous bioavailability. To overcome these problems, a novel surfactant-based nanovesicular delivery system was developed. The aim of this study was to develop and evaluate a nanovesicular spanlastic gel loaded with EBN for sustained topical delivery and improved bioavailability. The EBN spanlastic vesicles were formulated using a modified ethanol injection method. Using a 2³ factorial design and Stat-Ease 360^® software, eight formulations were evaluated to optimize particle size and entrapment efficiency. The vesicles exhibited nano size (93.5 nm – 368.6 nm) and high entrapment efficiency (94.14 % – 97.30 %). The optimized formulation had the smallest size and the highest entrapment efficiency. TEM analysis confirmed non-agglomerated circular vesicles. In vitro studies showed an enhanced drug release of 87.2 % within 8 h. The optimized spanlastic formulation was incorporated into a 1 wt% Carbopol 934 gel and tested for parameters such as viscosity, spreadability, drug content, skin irritation and in vitro release. Ex vivo permeation studies showed better drug release (97.3 %), higher flux (0.137 mg cm⁻² h⁻¹) and a higher permeability coefficient (0.0137) compared to conventional formulations. The results suggest that the nano spanlastic gel is a promising antifungal delivery system for EBN.