Design, Development, and Characterization of Luliconazole-loaded Bilosomal Gel for Enhanced Cutaneous Delivery

Abstract

Luliconazole (LZ) is a broad-spectrum antifungal agent whose topical performance is limited by poor aqueous solubility and restricted skin penetration. This study aimed to develop and characterise LZ-loaded bilosomes incorporated into a topical gel to enhance cutaneous delivery. Eight bilosomal formulations were prepared by thin-film hydration using soy phosphatidylcholine, cholesterol and Span 80, followed by incorporation of the optimised bilosomal suspension into a Carbopol/HPMC gel. The formulations were assessed for particle size, polydispersity, zeta potential, entrapment efficiency, morphology, in vitro drug release, skin permeation, antifungal activity and stability. BLS-6 showed a particle size of 187.45 ± 5.12 nm, a PDI of 0.289 ± 0.042 and an entrapment efficiency of 86.34 ± 3.21%. The vesicles showed spherical, well-defined morphology without noticeable aggregation or visible drug crystals. At 24 h, BLS-6 released 71.23 ± 3.45% of the encapsulated drug, compared with 94.12 ± 2.89% from the free drug. Skin permeation flux was 45.23 ± 2.89 μg/cm²/h versus 18.67 ± 1.45 μg/cm²/h for the control gel. The bilosomal gel showed MIC values of 2.5, 3.1 and 2.8 μg/mL against Candida albicans, Aspergillus niger and Trichophyton mentagrophytes, respectively. After 8 weeks, drug retention was 91.34 ± 2.45% at 25°C/60% RH and 85.67 ± 3.12% at 40°C/75% RH. These findings support further evaluation of the LZ-loaded bilosomal gel as a controlled topical delivery system.