Enhanced transdermal delivery of sinomenine hydrochloride by ethosomes for anti-inflammatory treatment

Sinomenine hydrochloride (SH) is a valuable anti-inflammatory drug. However, the application of SH is limited by its short half-life and side effects. The aim of this study was to develop a novel SH-loaded ethosome (SE), and make it safe and effective in anti-inflammatory treatment. In this study, the SE was prepared by the injection method and optimized by the single factor test and uniform design. The in vitro skin permeation and deposition of SE was measured and the skin irritation was evaluated by Draize patch test. Finally, the in vivo anti-inflammatory ability of SE was studied by the xylene-induced ear edema test. As a result, the optimized SE was 157.08 nm and negatively charged. The skin penetration and deposition of SH from SE was 663.8 μg/cm² and 18.5 μg/cm², respectively. The skin irritation study suggested that the SE showed desirable skin tolerability. Moreover, the SE showed a significant inhibition effect on the ear edema (30.01%). In conclusion, the SE was demonstrated to be a promising vehicle for transdermal delivery of SH and have potential application in the treatment of local inflammation.