OBJECTIVETo study bioequivalence of Sinomenine patch made by different preparation process, and to testify feasibility and superiority of microdialysis as a new method in topical bioequivalence study.

METHODNormal gel patch and liposome gel patch of sinomenine were prepared by different preparation, nude mouse served as the experimental subjects sampling method of drug in the skin was tissue homogenization microdialysis, and drug concentration in dialysate was determined by HPLC.

RESULTResults of tissue homogenization showed that liposome gel patch leads more remainder drug in the skin of nude mouse than normal gel patch, and results of microdialysis showed that liposome gel patch led higher instantaneous drug concentration than normal gel patch. Concentration-time curve of sinomenine in the skin accorded with the results of most dermal delivery systems studies over the world.

CONCLUSIONTopical bioequivalence of liposome gel patch of sinomenine is higher than that of normal gel patch of sinomenine. Microdialysis can be used to study bioavailability and bioequivalence of different preparation.