Classification, characteristics and application of chemical reference substance of traditional Chinese medicine

1.

Standard materials have their specific purpose of use

1.

Mainly used for identification of thin layer chromatography, high performance liquid chromatography and gas chromatography in the standard of traditional Chinese medicine

In the "Pharmacopoeia of the People's Republic of China" (referred to as "Chinese Pharmacopoeia") and other national drug standards in China, the reference substances used for identification are all compounds with the same ingredients as the identified components, which can be called "equivalent controls"; while the "European Pharmacopoeia" (EP) and "United States Pharmacopoeia" (USP) included in the botanical standards, there is also a model of non-identified component control, called "reference substance control"

The method of "Chinese Pharmacopoeia" uses the reference substance to identify the components, which does not require high TLC test conditions, which is conducive to accurate judgment under different test conditions

The purity requirement of the reference substance for identification is different from the reference substance for limit inspection and content determination, and the purity is generally above 95%

2.

The limit check included in the standard of Chinese medicine includes general limit check and quantitative limit check

3.

At present, the content determination methods in the standards of Chinese medicinal materials, Chinese medicinal extracts and preparations of Chinese medicinal preparations are mainly chromatography, including thin-layer chromatography scanning, high performance liquid chromatography, gas chromatography, etc.

Second, the characteristics of Chinese medicine chemical reference substance

Most of the chemical reference substances of Chinese medicine are derived from plants and animals, and are obtained through certain extraction, separation and preparation processes

1.

Corresponding spectroscopy techniques are used for structural identification

2.

Purity analysis is mainly carried out by thin layer chromatography (TLC), high performance liquid chromatography (HPLC), gas chromatography (GC) and other methods.
Differential calorimetric scanning (DSC), nuclear magnetic resonance (NMR) and mass spectrometry ( MS) method
.

3.
Physical and chemical analysis

The physical and chemical properties of the chemical reference substance of traditional Chinese medicine are closely related to the identification, use and storage conditions
.
The physical and chemical analysis mainly includes the study of melting point, solubility, moisture absorption and stability
.

4.
Fixed value

At present, the reference substance for content determination mainly adopts the legal value of mass balance
.

Based on the above test and research results, the purity, amount, use, storage and other related information are given in the instruction manual of the chemical reference substance of traditional Chinese medicine
.

3.
Application and use of chemical reference substance of Chinese medicine

In the standard of Chinese medicinal materials (prepared pieces), extracts, and preparations of Chinese herbal medicines included in the first part of the "Chinese Pharmacopoeia" (2010 edition), there are more than 400 chemical reference substances of Chinese medicine that need to be used
.
The reference substance and its application varieties are listed in the attached table of this book
.

The chemical reference substances of traditional Chinese medicine currently distributed by the China Food and Drug Control Institute are attached with labels and instructions for each variety, including the name, number, batch number, structural formula, molecular formula, molecular weight, loading, use, and pre-use treatment methods of the reference substance.
, Storage conditions and providing unit information, some extract varieties provide comparative map information
.
The reference substance for content determination also provides content information
.
When using, you need to really read the instructions and product labels
.
The reference substance for content determination needs to be converted during use
.
The pre-use treatment method is divided into two cases, no need to handle during use and dry treatment before use, according to the current packaging and indication of the reference substance
.
The difference should be noted .

In addition to liquid, brown ambe bottle packaging generally contains a certain amount of water, which has been deducted when the value is determined; or because the variety has moisture inducing properties, it is packaged in a melt-sealed ambe bottle
.
There is no need to deal with it during use, and it can be used once after opening
.

Varieties packaged in brown glass bottles generally have low water content or no obvious hygroscopicity; or because they have hygroscopicity, they need to be dried under reduced pressure before use to remove possible adsorbed moisture.
Drying treatment is required before use according to the requirements of the instructions
.

The assigned value of the national drug standard substance is only valid when used in the specified purpose
.
If it is used for other purposes, its applicability is determined by the user for nothing
.

The standard substance solution of the reference substance is prepared before use in principle.
It is not recommended to store the solution unless the user proves its applicability
.