Objective: To optimize preparation technology of Acanthopanax senticosus extract sustained-release microsphere. Method: With comprehensive scoring of drug-loading and entrapment efficiency as index

orthogonal test was used to investigate influence of four main factors on preparation technology

including the mass fraction of sodium alginate and CaCl2

A. senticosus extract-sodium alginate and cross-linking time. Result: Optimum Preparation technology was:the mass fraction of sodium alginate 3.5%

A. senticosus extract-sodium alginate 1:1

cross-linking time 2 h

the mass fraction of CaCl2 4.0%

drug loading and entrapment efficiency of prepared microsphere were10.11%

21.74%

respectively.Prepared A. senticosus extract sustained-release microsphere was dark brown and roundness

particle size was about 0.45 mm

cumulative release was up to 96.12% in 12 h. Conclusion: Optimized preparation technology was simple and reliable.