Objective: To improve secondary ethanol precipitation and subsequent processes of Guanxinning injections. Method: With residue mass as index

necessity of frozen and filtration steps after secondary ethanol precipitation was investigated.With the contents of sodium danshensu

protocatechuic aldehyde

rosmarinic acid

ferulic acid and salvianolic acid B as indexes

effects of the concentration of adding ethanol

pH and ethanol concentration on secondary ethanol precipitation and subsequent processes were investigated. Result: Frozen step in original standard process could be negligible.The contents of five kinds of characteristics components in Guanxinning injections were all improved effectively when ethanol content was adjusted to 80% with 90% ethanol in secondary alcohol precipitation and pH was adjusted to 8.0-8.2 after secondary alcohol precipitation. Conclusion: Improvement process of Guanxinning injections could better control liquid color and finished products quality

it could be widely applied with shortening production cycle.