Objective: To develop a HPLC method for determining the content of ecdysterone in Achyranthis bidentatae and Juejin Granula. Method: Ecdysterone was extracted from Radix Achyranthis bidentatae and Juejin Granula using reflux and ultrasonic extraction and optimizing the extraction condition. Determining the content of ecdysterone was determined by HPLC

the chromatography was performed on a Kromasil C18 column (250 mm×4.6 mm

5 μm) at 30 ℃ with acetonitrile-water (17∶83) as mobile phase. The flow rate was 1.0 mL·min-1 and UV detection wavelength was at 242 nm. Result: The optimal extraction condition of Radix Achyranthis bidentatae: reflux extracting two times by adding 15 times of 70% ethanol and once for 1 hour

the optimal extraction condition of Juejin Granula: ultrasonic extracting with warter as solvent for 30 min. The linear range of ecdysterone was 10.37-103.7 mg·L-1 (r=0.999 5)

the regress equation was Y=24 867X+1 563(r=0.999 5)

the recoveries were 97.8% and 97.9%

RSDs were 1.8% and 1.4% (n=9). Conclusion: The method is accurate

available and reduplicate

and providing the basis for evaluating the quality of Radix Achyranthis bidentatae and Juejin Granula.