Objective:To optimize ethanol extraction process of Didang capsule.Method:Taking comprehensive extract rate of rhein

emodin and chrysophanol as evaluation index

the content of index components were determined by HPLC

extraction temperature

the concentration of ethanol

dosage of ethanol

extraction time

and extraction times were selected by single factor test;Ethanol extraction process of Didang capsule was optimized by orthogonal design

with the concentration of ethanol

ethanol dosage and extraction time were chosen as factors.Result:Optimum ethanol extraction process was as follows:coarse powder of the whole prescription was subjected to reflux extraction for 2 times with 8 fold volume of 70% ethanol at 90 ℃

each extraction lasting 40 min.Conclusion:This optimized process was reasonable and reliable

which could serve as references for industrial large scale production of Didang capsule.