Abstract: The sinomenine hydrochloride (SH) patch, a topical drug delivery system, was prepared and characterized. The in vitro release was studied according to the paddle-over-disk method in the appendix of Chinese Pharmacopeia (appendix XD, 2005). Stability of SH patch was evaluated at accelerated testing conditions (40 °C, 75% RH). Pharmacological and pharmacokinetics study were also performed. It was found that the release of SH from patches depended on pH value of the release medium. There were no significant differences between SH patches stored for 6 mon and those stored for 0 mon in the drug content, initial adhesion, lasting stickiness, peeling strength and in vitro release. SH patches exhibited better anti-inflammatory activity as well as analgesic efficacy. More importantly, primary pharmacokinetic parameters of SH patch, such as Cmax and AUC, were much lower than those of SH solution dosed orally. In conclusion, the patch might be a promising delivery system for SH, which bypassed the gastrointestinal tract and was a convenient, efficacious, safe and non-invasive delivery method.

Key words: Sinomenine hydrochloride, Patch, Stability, Pharmacokinetics, Release, Pharmacodynamics