Objective:To optimize prescription ratio of tetrahydropalmatine gel. Method: With 24 h accumulative permeation amount as index

the amount of carbomer

azone

propylene glycol

glycerine was chosen as investigating factors

prescription of tetrahydropalmatine gel was optimized by orthogonal design

and to examine in vitro drug release property of this gel. Result: Optimum formulation contained 1% tetrahydropalmatine

0.5% carbomer-940

3% azone

15% propylene glycol

10% glycerol. Conclusion: This optimized formulation was reasonable

preparation technology was stable and simple

its in vitro penetration was in line with zero order kinetic equation.