Comparative Analysis and Characteristic Verification of the Quality Standard of Milk Thistle Extract

Introduction:: Milk thistle extract is widely used in dietary supplements due to its strong hepatoprotective effect. There are some differences in the quality characteristics and standard values of milk thistle extract set by pharmacopoeias and standards in various countries and regions. Method: To promote the standardization of quality standards for milk thistle extract, this paper summarized and compared the standard characteristics and related values settings in four different standards. At the same time, actual samples were tested for the characteristics that appeared more frequently in standard. We found that the ratio algorithm of silymarin set in the pharmacopoeia standards was not reasonable and could blur the quality of related products from the test results, especially without limiting the total amount of silymarin in the standard. Results: We suggested setting standard values for all six silymarin characteristics, establishing more universal detection methods, and preparing relevant reference materials to match the detection methods. Based on the comparison of standards and test data, the characteristics of the ethanol content, ethyl acetate content, methanol insoluble substances, heavy metal content, and microbial characteristics should draw more attention and should be considered in the future for setting newly formulated standards. Conclusion: This paper lays the data foundation for developing higher quality standards for milk thistle extract, which plays an important role in promoting the international trade of milk thistle extract.