Ethosomal Delivery Systems for Beta-Sitosterol: Formulation and Stability Studies for Dermatological Applications

Abstract

Successfully delivering hydrophobic bioactives for skin-related uses continues to pose a considerable challenge because of issues with solubility, stability, and permeability. This research explores ethosomal delivery mechanisms for beta-sitosterol, a natural anti-inflammatory and antioxidant substance derived from plants. Ethosomes, which are lipid-based vesicular carriers that include ethanol, were developed through a thin-film hydration method and fine-tuned for optimal encapsulation efficiency, stability, and skin penetration capabilities. The encapsulation efficiency peaked at 30% ethanol, reaching 88%, accompanied by nanoscale vesicles measuring 145 ± 5 nm and a stable zeta potential of -35 ± 1 mV when stored under refrigerated conditions. Studies conducted in vitro revealed a prolonged release of beta-sitosterol, showing 55 ± 4% at the 12-hour mark, in contrast to traditional emulsions. Research on skin permeation indicated that ethosomal formulations markedly improved penetration (45 ± 3 µg/cm²) and retention (25 ± 2 µg/cm²) when compared to emulsions. Research on stability demonstrated that ethosomes preserved their integrity when stored under refrigerated conditions for a duration of three months. The results highlight ethosomal systems as a potentially effective method for administering beta-sitosterol in skin-related therapies.