Curcumin cubosomal emulgel: Mechanistic approach to improved fungal cell membrane targeting

Abstract

Fungal infections, mainly caused by Candida and Aspergillus spp, are the most common dermatological issue globally. Current treatments face poor absorption and increased resistance. Curcumin from Curcuma longa offers effective and safe alternatives that reduce ergosterol production and cause fungal cell death, but is hindered by low bioavailability and photodegradation. A novel approach is developed to enhance curcumin's stability and efficacy. This study aims to develop a novel topical herbal cubosomal emulgel to enhance drug stability, bioavailability, protect against photodegradation, and achieve antifungal activity through controlled and targeted release. Topical herbal cubosomes formulated using curcumin, glyceryl monooleate (GMO), Pluronic F127, and distilled water. The characterisation covered particle length, zeta potential, and morphology analysis by field emission scanning electron microscopy (FESEM). The optimised curcumin-loaded cubosomal dispersion was incorporated into an emulgel with carbopol 940 940 and chitosan using a cold method, then evaluated and optimised using Design of Experiments. (DOE). The F3 (GMO 9%) formulation was optimised based on characterisation and entrapment efficiency. Drug release studies showed the Carbopol 940-based formulation (C1) had an enhanced release rate of 87.8% within 8 hours. Further optimisation with Design of Experiments (DOE) demonstrated the cubosomal emulgel's controlled release of 82.3% over 8 hours. Zone of Inhibition (ZOI) tests against Aspergillus niger revealed that the cubosomal emulgel preserved curcumin's photodegradation, unlike pure curcumin. Curcumin photodegradation is effectively prevented by the developed cubosomal emulgel formulation, which also exhibits a controlled drug-release profile.