OBJECTIVE To study the influence of penetration enhancers on the transdermal absorption in vitro and explore in vivo pharmacodynamic responses of Shuangwu fractures prescription with or without enhancers.METHODS Skin permeation of piperine,the main constituent of Shuangwu fractures prescription,was evaluated by the Franz diffusion cell method with isolated rat skin.Different kinds,percentages and concentrations of penetration enhancers were applied.Furthermore,the analgesic and anti-inflammatory effects of the formula suspension with and without penetration enhancers were evaluated by hot-plate pain trial and xylene-induced ears edema method.RESULTS Azone combined with NMP was found to be the optimal penetration enhancer with the steady state flux up to 4.171 2 μg·cm^-2·h^-1.The greatest penetration efficiency of piperine can be achieved by the compound enhancer Azone and NMP(3:7) at 3%.Shuangwu fractures prescription showed positive effect on analgesis and anti-inflammatory,and the effect was enhanced with the added penetration enhancers(P<0.1).CONCLUSION 3% Compoud penetration enhancer,Azone and NMP(3:7),can achieve the best enhancerment on transdermal penetration of piperine in vitro.Shuangwu fractures perscription containing this enhancer can get increased anti-inflammatory and analgesic effect in vivo.