Use of Modified Casein Method for Radix Salvia Miltiorrhiza Injection to Achieve Tannin Content Control

OBJECTIVE Use of Modified Casein Method for Radix Salvia miltiorrhiza injection to achieve tannin content control, to ensure the quality of injection. METHODS Determination method of tannin in Chinese Pharmacopoeia (casein method) was improved by setting the suitable sample dilution ratio, establishing determination method of tannin in Danshen injection. RESULTS Modified determination method has achieved good results, tannin content is 0.83-2.06 mg·mL^-1 in commercial samples. CONCLUSION The requirements of Tannin limit is inconsistent in two limit tests in Chinese pharmacopoeia, tannin content determination in production control and quality inspection is of practical significance.