ISO 21756:2026

• Abstract:

  This document specifies the technical requirements for the quality and safety of industrial manufacturing procedures and quality of Salvia miltiorrhiza root and rhizome aqueous extract granules. It is applicable to Salvia miltiorrhiza root and rhizome aqueous extract granules that are sold and used in international trade.

• Status: Published
• Publication Date: 21-Jul-2026
• ICS: 11.120.10 - Medicaments
• Technical Committee: ISO/TC 249 - Traditional Chinese medicine
• Drafting Committee: ISO/TC 249 - Traditional Chinese medicine
• Current Stage: 6060 - International Standard published
• Start Date: 22-Jul-2026
• Due Date: 09-Nov-2026
• Completion Date: 22-Jul-2026

ISO 21756:2026 is an International Standard published by ISO for Salvia miltiorrhiza root and rhizome aqueous extract granules. It specifies technical requirements for industrial manufacturing procedures, quality, and safety for granules sold and used in international trade. This is the first edition, and it is written for manufacturers, laboratories, and quality teams that need a clear basis for production control and release testing.

What does ISO 21756:2026 specify?

ISO 21756:2026 covers the technical requirements for making, identifying, testing, and storing Salvia miltiorrhiza root and rhizome aqueous extract granules. The document is organized into clauses on scope, references, terms, manufacturing requirements, description, identification, safety assurance, test methods, and storage, followed by informative annexes.

Annex	What it covers
Annex A	Manufacturing procedures, from pretreatment through packaging and labelling
Annex B	Safety requirements in different pharmacopoeias and standards
Annex C	Thin-Layer chromatographic identification
Annex D	Determination of characteristic chromatogram
Annex E	Determination of marker compound content
Annex F	Determination of ethanol-soluble extractives

In practice, the standard gives one document that links production steps to identity tests, safety checks, and storage expectations.

What are the key requirements of ISO 21756:2026?

ISO 21756:2026 sets out a small number of control points that matter most in production and quality control: raw material control, product identity, chemical quality, safety testing, and storage. Together, these clauses tell a manufacturer what to verify before granules enter trade.

Raw materials and batch design

Clause 4 requires the Salvia miltiorrhiza root and rhizome raw materials to conform to ISO 21314. It also states the equivalence relationship used for the granules: 1 gram of Salvia miltiorrhiza root and rhizome aqueous extract granules corresponds to 2 g of Salvia miltiorrhiza decoction pieces.

That matters because production records, yield calculations, and label claims have to be based on the same starting material relationship. Annex A gives the manufacturing route that supports this ratio.

Product description and identity

Clause 5 describes the finished granules as yellowish-brown to brown, with a slight odour and a slightly bitter, astringent taste. Clause 6 then uses several identity and consistency checks.

Clause 6.1 requires Thin-Layer chromatographic (TLC) identification against Salvia miltiorrhiza reference material and salvianolic acid B. Clause 6.2 requires a characteristic chromatogram with eight characteristic peaks and the reference peak for salvianolic acid B. In practice, these tests help confirm that the product is what it claims to be and that the chemical profile is consistent from batch to batch.

Chemical quality indicators

Clause 6.3 uses salvianolic acid B as the marker compound and sets an acceptable content range. Clause 6.4 requires ethanol-soluble extractives to meet a minimum level, and clause 6.5 limits water or moisture content. These checks are important because they reflect extraction efficiency, drying quality, and storage stability.

Clause 6.6 points particle size and particle size distribution to ISO 23419, while clauses 6.7 and 6.8 link dissolution or disintegration and uniformity of dosage unit to ISO 23419 and ISO 19609-1. That means the document does not restate all performance details itself; it tells users which ISO methods and limits apply.

Safety assurance

Clause 7 requires testing for heavy metals and harmful elements, pesticide residues, and microorganisms. It specifically calls for determination of lead, cadmium, arsenic, mercury, and copper; pesticide residues such as DDT and BHC; and microbiological quality including the total number of aerobic bacteria, molds and yeasts, with Escherichia coli not detected.

This matters because the standard treats contamination control as part of product quality, not as a separate issue. Annex B helps users compare safety expectations across pharmacopoeias and standards.

Test methods

Clause 8 connects each quality requirement to a test method. TLC identification refers to Annex C, the characteristic chromatogram to Annex D, and marker compound content to Annex E. The document also points moisture, particle size, dissolution or disintegration, and uniformity of dosage unit to ISO 19609-1, heavy metals to ISO 18664, pesticide residues to ISO 22258, and microorganism testing to ISO 22467.

For a laboratory, this clause is the practical bridge between the acceptance criteria and the procedure used to measure them.

Storage and transport

Clause 9 says storage conditions should refer to ISO 22217 and adds practical handling expectations: a tidy storage area, no cross-contamination risk, control of humidity and temperature, and moisture protection. It also states that transportation should protect the product from light, moisture, pollution, foreign substances, odor transfer, and damage.

That is important for maintaining the identity and safety established during manufacturing and testing.

What terms does ISO 21756:2026 define?

ISO 21756:2026 defines a few core terms that shape how the product is made and judged.

• Granule - coated or uncoated small grains, about 0,2 mm to 4 mm in diameter, made from powdered extract and excipients.
• Extract - a liquid preparation obtained by using water as a solvent for medicinal plants.
• Dry powder - fine particles obtained by drying concentrated extract.
• Dry paste rate - the ratio of dry powder obtained after extraction, concentration, and drying to the amount of decoction pieces used as starting material.

These definitions matter because they fix the product form and the manufacturing yield basis used throughout the standard.

Who uses ISO 21756:2026?

ISO 21756:2026 is used by manufacturers of Traditional Chinese medicine products, quality control laboratories, and quality assurance teams working with Salvia miltiorrhiza root and rhizome aqueous extract granules. It is also relevant for buyers, technical evaluators, and regulators involved in international trade.

In practice, users apply it to raw material acceptance, process control, identity testing, release testing, packaging decisions, storage checks, and supplier qualification. The standard is especially useful where a company needs one technical reference for both manufacturing and quality assurance.

Which standards are used with ISO 21756:2026?

ISO 21756:2026 relies on several referenced and related standards that supply test methods, material requirements, and packaging guidance.

Standard	Contribution to ISO 21756:2026
ISO 18664	Heavy metals testing
ISO 19609-1	General requirements for raw materials and finished products, and methods for moisture, particle size, dissolution or disintegration, and uniformity of dosage unit
ISO 21314	Raw material requirements for Salvia miltiorrhiza root and rhizome
ISO 22258	Pesticide residue testing by gas chromatography
ISO 22467	Microorganism testing
ISO 23419	General requirements for manufacturing procedures and quality assurance of granules

The document also names ISO 18668-4 and ISO 21371 for labelling in Annex A, and ISO 22217 for storage conditions. Those references help users align packaging, labelling, and storage practices with broader Traditional Chinese medicine requirements.

What does the ISO 21756:2026 document contain?

ISO 21756:2026 contains a manufacturing outline, identity tests, chemical quality tests, safety requirements, and storage guidance. Annex A gives a stepwise production route, including pretreatment, extraction, liquid-solid separation, concentration, spray drying, granulation, packaging, and labelling.

The technical annexes are especially useful for laboratories and process engineers. Annex C describes a TLC procedure with preparation of test and reference solutions and a figure showing typical chromatograms. Annex D gives an HPLC method for the characteristic chromatogram, including the gradient program and a figure of the reference profile. Annex E gives an HPLC assay for salvianolic acid B and explains how the content is calculated. Annex F gives the extraction and weighing steps used to determine ethanol-soluble extractives.

Annex B is a comparison table. It helps users see how different pharmacopoeias and standards treat safety items such as heavy metals, pesticide residues, aflatoxins, and microorganisms for this product family.

International
Standard
ISO 21756
First edition
Traditional Chinese medicine —
2026-07
Salvia miltiorrhiza root and rhizome
aqueous extract granules
Médecine traditionnelle chinoise — Granulés d'extrait aqueux de
racine et de rhizome de Salvia miltiorrhiza
Reference number
© ISO 2026
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
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or ISO’s member body in the country of the requester.
ISO copyright office
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Phone: [phone]
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Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Requirements of manufacturing procedures . 2
5 Description . . 2
6 Qualitative identification . 2
6.1 Thin-Layer chromatographic (TLC) identification .2
6.2 Characteristic chromatogram .2
6.3 Marker compound .2
6.4 Determination of ethanol-soluble extractives .2
6.5 Determination of water or moisture content .2
6.6 Particle size and particle size distribution .2
6.7 Dissolution or disintegration .3
6.8 Uniformity of dosage unit .3
7 Requirements of safety assurance . 3
7.1 Heavy metals and harmful elements .3
7.2 Pesticide residues .3
7.3 Microorganism .3
8 Test methods . 3
8.1 Thin-Layer chromatographic identification .3
8.2 Determination of characteristic chromatogram .3
8.3 Determination of marker compound content .3
8.4 Determination of ethanol-soluble extractives .3
8.5 Determination of water or moisture content .3
8.6 Determination of particle size and particle size distribution .3
8.7 Dissolution or disintegration test .4
8.8 Estimation of uniformity of dosage unit .4
8.9 Determination of heavy metals and harmful elements content .4
8.10 Determination of pesticide residues content .4
8.11 Microorganism test .4
9 Storage . 4
Annex A (informative) Salvia miltiorrhiza root and rhizome aqueous extract granules
manufacturing procedures . . 5
Annex B (informative) Safety requirements in different pharmacopoeias and standards . 7
Annex C (informative) Thin-Layer chromatographic identification . 9
Annex D (informative) Determination of characteristic chromatogram .11
Annex E (informative) Determination of marker compound content .13
Annex F (informative) Determination of ethanol-soluble extractives .15
Bibliography .16

iii
Foreword
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This document was prepared by Technical Committee ISO/TC 249, Traditional medicine, Subcommittee SC 1,
Traditional Chinese medicine.
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iv
Introduction
Salvia miltiorrhiza root and rhizome (the Chinese Pinyin name: Danshen) has been used as traditional Chinese
medicine for over 2 500 years and has been developed into various herbal medicinal products in many
countries. Salvia miltiorrhiza root and rhizome aqueous extract granules are alternative forms of dosage
for Salvia miltiorrhiza decoction pieces, which are obtained through modern pharmaceutical technology
of extraction, concentration, drying and granulation. Salvia miltiorrhiza root and rhizome aqueous extract
granules are well-suited for modern technological applications because they can be dosed accurately, quality
controllable, ready-to-take, and easy to store, thereby replacing difficult dose calculation, poor portability,
and longer decoction for Salvia miltiorrhiza decoction pieces.
ISO 21314 and ISO 23419 provide references for the quality assurance of Salvia miltiorrhiza root and rhizome
aqueous extract granules. However, the manufacturing technology and quality control of Salvia miltiorrhiza
root and rhizome aqueous extract granules have unique characteristics and requirements. Therefore, it is
important to establish technical specifications for manufacturing technology and quality requirements
of Salvia miltiorrhiza root and rhizome aqueous extract granules, to ensure their quality and safety, in
accordance with international standards.

v
International Standard ISO 21756:2026(en)
Traditional Chinese medicine — Salvia miltiorrhiza root and
rhizome aqueous extract granules
1 Scope
This document specifies the technical requirements for the quality and safety of industrial manufacturing
procedures and quality of Salvia miltiorrhiza root and rhizome aqueous extract granules. It is applicable to
Salvia miltiorrhiza root and rhizome aqueous extract granules that are sold and used in international trade.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 18664, Traditional Chinese Medicine — Determination of heavy metals in herbal medicines used in
Traditional Chinese Medicine
ISO 19609-1, Traditional Chinese medicine — Quality and safety of raw materials and finished products made
with raw materials — Part 1: General requirements
ISO 21314, Traditional Chinese medicine — Salvia miltiorrhiza root and rhizome
ISO 22258, Traditional Chinese medicine — Determination of pesticide residues in natural products by gas
chromatography
ISO 22467, Traditional Chinese medicine — Determination of microorganisms in natural products
ISO 23419, Traditional Chinese medicine — General requirements for manufacturing procedures and quality
assurance of granules
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
granule
coated or uncoated small grains which range from approximately 0,2 mm to 4 mm in diameter, made from a
uniform mixture of powdered extract and excipients
[SOURCE: ISO 23419: 2021, 3.3, modified — Notes to entry removed.]
3.2
extract
liquid preparation obtained by using water as a solvent for medicinal plants
[SOURCE: ISO 19617: 2018, 3.10, modified — The definition of "preparation" has been specified.]

3.3
dry powder
fine particles obtained by drying concentrated extract (3.2)
3.4
dry paste rate
ratio of the amount of dry powder (3.3) obtained by extracting, concentrating, and drying to the amount of
decoction pieces as starting materials
4 Requirements of manufacturing procedures
a) The specification of the Salvia miltiorrhiza root and rhizome raw materials shall conform to the
requirements of ISO 21314.
b) One gram of Salvia miltiorrhiza root and rhizome aqueous extract granules is equivalent to 2 g of Salvia
miltiorrhiza decoction pieces.
NOTE For Salvia miltiorrhiza root and rhizome aqueous extract granules manufacturing procedures, see Annex A.
5 Description
Yellowish-brown to brown granules with a slight odour, and slightly bitter and astringent taste.
6 Qualitative identification
6.1 Thin-Layer chromatographic (TLC) identification
The spot in the TLC with the test solution corresponds in position and colour to the spot obtained with
the reference herbal solution of Salvia miltiorrhiza and the reference standard solution of salvianolic acid B
(C H O ).
36 30 16
6.2 Characteristic chromatogram
The characteristic chromatogram of the test sample should present 8 characteristic peaks, and the
corresponding peak of reference salvianolic acid B is S-peak. The relative retention time of characteristic
peaks 1 to 8 calculated should be within ±10 % of the specified value.
6.3 Marker compound
The content of salvianolic acid B (C H O ) should be between 28,0 mg/g and 59,0 mg/g.
36 30 16
6.4 Determination of ethanol-soluble extractives
Ethanol-soluble extractives should not be less than 9,3 %.
6.5 Determination of water or moisture content
Water or moisture content in percentage mass should not be more than 8,0 %.
6.6 Particle size and particle size distribution
The particle size distributions are specified in ISO 23419.

6.7 Dissolution or disintegration
The dissolution or disintegration test shall be determined and shall meet the requirements specified in
ISO 23419.
6.8 Uniformity of dosage unit
The uniformity of dosage units should meet the requirements of ISO 19609-1.
7 Requirements of safety assurance
The safety requirements of Salvia miltiorrhiza root and rhizome and Salvia miltiorrhiza root and rhizome
aqueous extract granules in different pharmacopoeias and standards are shown in Annex B.
7.1 Heavy metals and harmful elements
The content of lead, cadmium, arsenic, mercury and copper shall be determined.
7.2 Pesticide residues
The content of pesticide residues such as DDT (dichloro-diphenyl-trichloroethane), BHC (benzene
hexachloride) should be determined.
7.3 Microorganism
The total number of aerobic bacteria, molds and yeasts shall be determined, and Escherichia coli shall not be
detected.
8 Test methods
8.1 Thin-Layer chromatographic identification
See Annex C for additional information.
8.2 Determination of characteristic chromatogram
See Annex D for additional information.
8.3 Determination of mar
...