Curcumin loaded ethosomes for transdermal application: Formulation, optimization, in-vitro and in-vivo study

Curcumin has an excellent safety profile with varied pleiotropic actions, including anti-inflammatory, antioxidant, antitumoural, anticancer, and antimicrobial activities, with the potential for neuroprotective activity but the poor oral bioavailability limits its use as an oral dosage form. Hence the present investigation was aimed to fabricate, develop and optimize ethosomes formulations of curcumin for transdermal application. The preparation of ethosomes was optimized using Box Behnken design (BBD) approach with three independent variables (concentration of lecithin, ethanol, and cholesterol) and three response variables (vesicle size, percent entrapment efficiency, and flux) using thin film dispersion method. Formulated ethosomes were evaluated for percent entrapment efficiency, vesicle size, polydispersity index, zeta potential, in-vitro permeation study, in-vivo studies and vesicular stability study. F4 formulation (optimized) containing 10 mg lecithin, 4.5% ethanol and 10 mg cholesterol demonstrated greater drug entrapment efficiency (81.2 +/- 3.12%) and smaller vesicle (228.8 nm) with desired flux (10.5 +/- 2.6 mu g/cm(2)/hr) through human cadaver skin (HCS). The in-vivo study revealed a significant increase in percent inhibition (58.8% for 7 h) of the F4 formulation as compared (p < 0.05) to oral administration. Stability study revealed no significant changes found during three months study. Thus, formulated curcumin loaded ethosomes could serve as the promising approach for transdermal delivery in pain management.