Research Progress on Quality Control Methods for Xiaochaihu Preparations

Round 1

Reviewer 1 Report

Review of the manuscript

ID separations-1415385

"Research progress on quality control methods for Xiaochaihu preparations" Guangzheng Xu, Hui Wang, Yingqian Deng, Keyi Xie, Weibo Zhao and Xingchu Gong

 

This review is devoted to the methods of quality control of Xiaochaihu (XCH) - a preparation of traditional Chinese medicine. Various solid dosage forms of this drug are described and technological schemes for their production are given. Qualitative and quantitative analysis of various dosage forms of XCH is described. The Fingerprint and specific chromatogram method is considered. The directions requiring additional research are identified, for example, improvement in the specificity of quality testing, etc.

 

The paper corresponds to the profile of the journal "Separations", although it could be presented in other journals, for example, "Nutraceuticals". Literary references, judging by the titles of the works, are presented correctly.

 

At the beginning of my review, I must say that I did not deal with the drug Xiaochaihu (XCH) and I cannot say how fully the authors presented the literature on this issue in their review. However, working with other preparations from natural raw materials allows me to make some general comments.

 

First, the subject of the study should be defined as specifically as possible. It seems to me that traditional drugs rarely have an exact quantitative composition; most likely, it may vary within some limits, which may be due to traditions or specific economic conditions. It also seems to me that plants of some species can be replaced by another species within this genus of plants. The authors themselves point out that only genus Bupleurum in China has 36 species, 17 varieties and 7 forms, among which there are poisonous ones. A similar diversity is characteristic of other components of XCH (glycyrrhizae, zingiberis, etc.). In Table 2, the authors give plants' mass ratio for various forms of the drug. What is this ratio? The only possible for XCH? The average of some sample? The ratio obtained by analyzing a specific batch of some manufacturer?

 

A good article in the Pharmacopoeia should answer all these questions. Also, this article should describe the analysis of the drug in order to establish its authenticity. In this review, the authors repeatedly refer to the Pharmacopoeia of China and Japan. For the Japanese Pharmacopoeia (link [15]), they should specify a specific page containing an article about the drug XCH. I did not find a link to the Pharmacopoeia of China in the list of references.

The authors do not cite separately the quality control methods described in the Pharmacopoeia. As I understood, such methods include: microscopic examination and TLC (Table 3) (qualitative analysis), as well as quantitative determination of baikalin (Table 4, the method of determination is not specified). For TLC, the conditions (solvent, carrier, 1D or 2D, detection method) should be given and, if possible, a characteristic picture of TLC should be given in this review or the Rf of characteristic spots and a link to the original work should be indicated.

Table 5 (typo in the text, 4 – l. 142) lists the published works on the quantitative detection of XCH preparations. The authors should say a few words about how quantitative measurements were carried out. It is unclear whether the Fingerprint and specific chromatogram methods belong to the Pharmacopoeia, or are these newly developed methods that can be attributed to "Research progress on quality control methods"? It would be good to give a Fingerprint chromatogram for XCH and its individual components, or provide a link to such works.

 

The authors need to emphasize what exactly is the progress in research methods. Is the progress a consequence of an outdated pharmacopoeia article (using old methods in it that do not give a complete description of the drug). Has a method been developed at the moment that allows you to reliably verify the quality of the XCH preparation and evaluate the content of all plant components in it?

 

Next, a few minor comments on the text of the review:

Authors should carefully edit the English language. For example, the term "prescription" is used, although the meaning in some places should be used "recipe", and in others - "recommendation". Line 17 – "should (?) be improved". In many places - "to set (up?) … the limits". Line 78 - "herbs (better plants) are extracted."

 

According to the general principles of scientific style, the tables in the publication should be as informative as possible and not duplicate information. Table 1 seems superfluous to me, this information can be conveyed in words, for example: "for the period from 2000 to 2020, the number of publications grew annually and ranged from 130 to more than 300 works." Table 2. It is not clear why Amount(g) is given in it and what these values refer to. It is clear that this is not the mass of one tablet. Since the Mass ratio (%) values are the same for XCH tablets and capsules, these columns can be combined. Columns with effervescent tablets and granules differ only in the first row: 31.0 and 30.9. Is this a typo and they can also be combined, or is 0.1% of an unspecified substance present in the composition? Why are there two sets of values for Shosaikoto Extract (Japanese)? Tables 3,4,5,6 - the title should be written before the table. Table 3 - why is there no TLC reference substance for XCH capsules? Table 4 – the first and third row, as well as the second and fourth, can most likely be combined, for example: "Not lower than 2.0 mg per tablet/capsule". At the same time, the mass of the dosage form is not specified. Table 5 - what does the "- -" sign in the "Other instructions" column mean? Repetition of the previous value "-//-" or lack of data (dash) "-"? Table 6 and further in the text - it is customary to write the names of compounds with capital letters, for example "Saikosaponin A".

It is usually not accepted to refer to Doctor's and Master's Thesises [5, 22, 29]. The main content of such works should be published as articles and the Thesises themselves are usually inaccessible to readers.

Link [14] - it is necessary to correct the hyperlink so that it opens an existing page. How acceptable is it to give a hieroglyphic name? There is an English version of this web page.

 

Conclusion: the review should be sent for revision, after clarifying the issues that have arisen, it can be published.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

The article is a complex one and very interesting for the readers. The authors describe very well the  impact of XCH on human body but maybe some explanations on the mechanism of XCH act on human body must be added. Also some authors opinion on the best qualitative and quantitative determinations of XCH should be insert in the manuscript. More, some conclusions in a more large extensive should be address.

Author Response

Please see the attachment.

Author Response File: Author Response.docx