Objective: To study in vitro release difference of oil-in-water microemulsion cataplasm and conventional cataplasm to liposoluble components from Euodiae Fructus. Method: According to ratio of Euodiae Fructus extract-isopropyl myristate-propylene glycol-ploysorbae 80-hydrogenated castor oil-water (0.3: 0.6: 3.6: 3.6: 3.6: 18) for preparing oil-in-water microemulsion

then microemulsion was added to matrix for preparing microemulsion cataplasm.In vitro diffusion method was adopted to determine in vitro cumulative permeation quantity of evodiamine and rutaecarpine in cataplasm. Result: Cumulative permeation quantity per unit area at 24 h of evodiamine and rutaecarpine in Euodiae Fructus oil-in-water microemulsion cataplasm were 1.86

1.40 times to conventional cataplasm

respectively. Conclusion: Release performance of liposoluble components from Euodiae Fructus in microemulsion cataplasm is better than those in conventional cataplasm

which is suitable for preparation of water-insoluble ingredients cataplasm.