Objective: To prepare o/w type emulsion with total coumarin from Cnidium monnieri

and investigate its in vitro anti-trichomonas vaginalis activity. Method: Total coumarin from C. monnieri was extracted by ultrasonic method with emulsification time

times and pressure

adding order of emulsifier as factors

single factor test was used to optimize preparation technology of C. monnieri emulsion

and its pharmacodynamic trial of in vitro anti-trichomonas vaginalis was investigated. Result: Preparation technology of C. monnieri emulsion was ascertained as follows:emulsification 3 times at 150 MPa

15 min each time

adding order of emulsifier with oil phase added to aqueous phase;and this emulsion had good inhibition on trichomonas vaginalis. Conclusion: This preparation technology was stable and feasible

minimum drug concentration of this emulsion had good inhibition effect to trichomonas vaginalis was 0.15-0.62 g·L-1.