Objective: To observe enhancement of transdermal diffusion rate of Kangmo paste by screening type of substrates and compound penetration enhancers. Method: HPLC was adopted to determine the content of paeoniflorin by taking methanol-0.1% glacial acetic acid (30: 70) as mobile phase and detection wavelength of 234 nm.Utilized skin on the back of SD rats

in vitro percutaneous absorption test was used by Frans diffusion cell method

with cumulative osmotic quantity in 12 h and penetration rate as indexes

which was used to evaluate release and transdermal performance of drug in different types of substrates

in order to select substrate type.Effects of composite permeability dose of azone and propylene glycol on in vitro percutaneous penetration of paeoniflorin in Kangmo paste were investigated by central composite design-response surface methodology. Result: Matrix of O/W emulsion was chosen;when accumulative release rate of paeoniflorin was 72.20% in 12 h

combination of penetration enhancer was 2.4% azone and 1.6% propylene glycol. Conclusion: This optimized substrate and penetration enhancer can significantly improve transdermal rate constant of Kangmo paste.