Objective: To optimize formulation technology of Angelicae Dahuricae Radix coumarin liposomes and investigate its release properties. Method: Liposomes of coumarin from Angelicae dahuricae Radix were prepared by film dispersion-supersonic method

based on single factor tests

with encapsulation efficiency and drug loading as comprehensive evaluation index

Box-Behnken design-response surface method was adopted to optimize formulation technology with proportion of phosphatidylcholine to cholesterin

ratio of phosphatidylcholine to coumarin and ultrasonic time as factors.The content of coumarin was determined by UV spectrophotometry

appearances and particle size of coumarin liposomes were examined with transmission electron microscopy. Result: Optimum formulation technology was as following:proportion of phosphatidylcholine to cholesterin (6:1)

proportion of phosphatidylcholine to coumarin (5:1)

ultrasonic time 34 min;Prepared coumarin liposomes had uniform size

showed spherical vesicles with good dispersion

particle size was (112.08±1.21) nm

encapsulation efficiency was (94.02-1.56)%

drug loading was (5.42±0.35)%.Cumulative release of coumarin was 100% in 3 h

cumulative release of mixed solution of coumarin and blank liposomes was 95.3% within 12 h

but that of Angelicae dahuricae Radix coumarin liposomes was 45.6% in 12 h. Conclusion: This optimized process was stable and suitable for industrial production

preparedcoumarin liposomes had high encapsulation efficiency and significant release effects with uniform morphology and particle size.