Formulation, Characterization, and Biological Assessment of Embelin-Loaded Glycerosomes

Despite embelin's (EB) promising biological activities including the hepatoprotective effect, its clinical use is constrained by inadequate solubility and low oral bioavailability, which restrict its therapeutic effectiveness. The current study aimed to address this gap by developing EB-loaded glycerosomes (GLSMs), an advanced vesicular system designed to improve oral bioavailability and enhance drug delivery to the liver. EB-loaded GLSMs were prepared using a thin-film hydration method and optimized via a 3² Box-Behnken design. The concentrations of soy lecithin and glycerol, along with the probe sonication cycle, were chosen as independent variables to study their effect on vesicle size and percentage drug entrapment. The prepared formulation was tested for vesicle size and its distribution, surface charge (zeta potential), and drug release and was also assessed in vivo. The optimized formulation exhibited a vesicle size of 214.41 ± 2.12 nm, a polydispersity index of 0.145 ± 0.02, a zeta potential of -30 ± 1.14 mV, and an entrapment efficiency (EE) of 94.74% ± 0.056%. Transmission electron microscopy images confirmed the presence of uniform, spherical vesicles with no signs of aggregation. The sustained-release properties of the GLSM formulation were evident, with 99% of EB released from the pure drug suspension within 2 h, compared with the same amount released from the EB-loaded GLSMs over 12 h. In vivo pharmacokinetic studies showed a significantly higher plasma maximum concentration (C_max), AUC_0-t, and AUC_0-∞ values for optimized EB-loaded GLSMs compared with aqueous EB suspension (p < 0.01), resulting in approximately 2.5-fold greater plasma bioavailability. Furthermore, rats treated with the optimized EB-loaded GLSMs showed significantly lower serum triglyceride and total cholesterol levels compared with those treated with the aqueous EB suspension. The developed EB-loaded GLSMs exhibited promising lipid-lowering and hepatoprotective effects, suggesting their potential as a therapeutic approach for liver diseases.