Skin permeation profile and anti-inflammatory effect of anemonin extracted from weilingxian

The aim of this study was to evaluate the skin permeability of anemonin, which was extracted from the Chinese herb weilingxian, and its potency of relieving the inflammation caused by rheumatoid arthritis (RA). To optimize the formulation, the solubility of anemonin in water and selected concentration of ethanol-water vehicles was determined. The effect of ethanol on the permeation of anemonin through human skin was then studied. Additionally, the influences of hydroxypropyl methylcellulose E50 (HPMC) and Carbomer 934 in different concentrations on the permeation of drug were investigated. Finally, the anti-inflammatory effect of the optimized formulation was assessed by murine model of xylene-induced ear edema. The results showed that the solubility and transdermal permeation of anemonin in ethanol-water vehicles linearly depended on the ethanol concentration. The combination of 30% ethanol and 3% Azone had a synergistic enhancement effect and was therefore selected for gel preparation. The 0.14% anemonin gel prepared with 1% HPMC exhibited the highest transdermal flux. The xylene-induced ear edema inhibitory rate of the optimized formulation was 48.85%. The results indicated that transdermal administration of anemonin is a potential modality for combating inflammation caused by RA.