ISO 5228:2023
(Main)Traditional Chinese medicine — Rheum palmatum, Rheum tanguticum and Rheum officinale root and rhizome
Traditional Chinese medicine — Rheum palmatum, Rheum tanguticum and Rheum officinale root and rhizome
This document specifies the quality and safety requirements of Rheum root and rhizome (the dried root and rhizome of Rheum palmatum Linne., Rheum tanguticum Maxim. ex Balf. and Rheum officinale Baill.). This document applies to Rheum root and rhizome that is sold and used as natural medicines in international trade, including Chinese materia medica (whole medicinal materials) and decoction pieces derived from these plants. This document does not apply to the processing methods and processed products of Rheum root and rhizome.
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INTERNATIONAL ISO
STANDARD 5228
First edition
2023-07
Traditional Chinese medicine —
Rheum palmatum, Rheum tanguticum
and Rheum officinale root and rhizome
Reference number
ISO 5228:2023(E)
© ISO 2023
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ISO 5228:2023(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2023
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
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
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ISO 5228:2023(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Description . .2
5 Requirements . 4
5.1 General characteristics . 4
5.2 Morphological features . 4
5.3 Identification . 4
5.3.1 Microscopic identification . . 4
5.3.2 Thin-layer chromatography (TLC) identification . 5
5.4 Rhaponticin . 5
5.5 Moisture . 5
5.6 Total ash . 5
5.7 Acid-insoluble ash . 6
5.8 Extractives . 6
5.9 Heavy metals . 6
5.10 Pesticide residues . 6
5.11 Marker compounds . 6
6 Sampling . 6
7 Test methods . 6
7.1 Macroscopic identification . 6
7.2 Thin-layer chromatogram (TLC) identification . 6
7.3 Rhaponticin identification . 6
7.4 Determination of moisture . 6
7.5 Determination of total ash . 6
7.6 Determination of acid-insoluble ash . 6
7.7 Determination of extractives . 7
7.8 Determination of heavy metals . 7
7.9 Determination of pesticide residues . 7
7.10 Determination of marker compounds . 7
8 Test report . 7
9 Packaging, storage and transportation . 7
10 Marking and labelling . 7
Annex A (informative) Thin-layer chromatography (TLC) identification .9
Annex B (informative) Determination of marker compounds by HPLC-UV .10
Annex C (informative) National and regional requirements for Rheum root and rhizome .17
Annex D (informative) Differentiation of the three species .19
Bibliography .21
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ISO 5228:2023(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO document should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use
of (a) patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed
patent rights in respect thereof. As of the date of publication of this document, ISO had not received
notice of (a) patent(s) which may be required to implement this document. However, implementers are
cautioned that this may not represent the latest information, which may be obtained from the patent
database available at www.iso.org/patents. ISO shall not be held responsible for identifying any or all
such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 249, Traditional Chinese medicine.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
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ISO 5228:2023(E)
Introduction
Rheum root and rhizome is the dry root and rhizome of Rheum palmatum Linne., Rheum tanguticum
Maxim. ex Balf. and Rheum officinale Baill. As one of the four traditional Chinese medicines in China,
Rheum root and rhizome is documented in Shennong materia medica. Rheum root and rhizome has
a wide range of clinical applications, high frequency of use and a long history of medicinal use. It is
recorded in traditional Chinese medicine books such as Yao pin hua yi, Yi xue zhong zhong can xi lu and
Su Wen.
Rheum root and rhizome has a complex chemical composition, including various compounds such as
anthraquinone, anthrone, tannin and polysaccharide. Modern pharmacological studies have shown that
sennoside and anthraquinone glucosides are the main components of Rheum root and rhizome that can
induce diarrhoea; free anthraquinones are antibacterial and antitumour active ingredients of Rheum
root and rhizome; n-butyrophenones have good anti-inflammatory and analgesic effects; gallic acid
glucosides and galloyl proanthocyanidins in the tannins have hypolipidemic effects; and d-catechin
and gallic acid have haemostatic effects. Moreover, Rheum root and rhizome also has the functions
of relieving phlegm, protecting the liver and gallbladder, and protecting against cardiovascular and
cerebrovascular diseases.
In global trade, taking Chinese customs data as an example, Rheum root and rhizome in China is mainly
exported to Japan, the Republic of Korea, the United States, Indonesia, Germany, Italy, Singapore,
France, Thailand, Vietnam and Malaysia. From 2012 to 2016, the average annual export trade volume
of Rheum root and rhizome in China was 7 128 400 US dollars, making it one of the main Chinese herbal
medicines exported by China.
There are 152 Chinese patent medicines containing Rheum root and rhizome in the Chinese
Pharmacopoeia (2015 Edition) and two preparations in Japanese Pharmacopoeia (17th Edition).
Rheum root and rhizome and its products have applications in a variety of medical fields, also involving
detoxification and beauty, lipid-lowering, weight-loss health products and food additives. Many
users believe that Chinese medicine is non-toxic and fail to take it strictly according to their doctor's
instructions, which can lead to excessive and chronic irregular use of Rheum root and rhizome and liver
and kidney damage.
As a globally used drug, Rheum root and rhizome is included in the pharmacopoeia of many countries
and regions, such as China, Japan, the Republic of Korea and Europe. At present, the quality control
of Rheum root and rhizome and its preparations is mostly based on the content of anthraquinones.
However, the medicinal ingredients of Rheum root and rhizome are not just anthraquinones. The
diversity of ingredients in traditional Chinese medicine determines that quality control should adopt a
multi-index quality evaluation model.
Furthermore, Rheum root and rhizome is ranked tenth in the priority list of single herbal medicines for
developing standards in ISO/TR 23975, which indicates its high priority. Therefore, it is necessary to
establish an International Standard of Rheum root and rhizome which unifies the quality and safety of
Rheum root and rhizome, ensures the safety and effectiveness of the medication and regulates trade in
the international market. The establishment of an International Standard for Rheum root and rhizome
is necessary to guarantee the clinical effectiveness, safety and controllability of this valuable medicine
in global commerce and trade.
As national implementation can differ, national standards bodies are invited to modify the values given
in 5.5, 5.6, 5.7 and 5.8 in their national standards. Examples of national and regional values are given in
Annex C.
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INTERNATIONAL STANDARD ISO 5228:2023(E)
Traditional Chinese medicine — Rheum palmatum, Rheum
tanguticum and Rheum officinale root and rhizome
1 Scope
This document specifies the quality and safety requirements of Rheum root and rhizome (the dried root
and rhizome of Rheum palmatum Linne., Rheum tanguticum Maxim. ex Balf. and Rheum officinale Baill.).
This document applies to Rheum root and rhizome that is sold and used as natural medicines in
international trade, including Chinese materia medica (whole medicinal materials) and decoction
pieces derived from these plants.
This document does not apply to the processing methods and processed products of Rheum root and
rhizome.
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 21371, Traditional Chinese medicine — Labelling requirements of products intended for oral or topical
use
ISO 22217:2020, Traditional Chinese medicine —Storage requirements for raw materials and decoction
pieces
ISO 22258, Traditional Chinese medicine — Determination of pesticide residues in natural products by gas
chromatography
ISO 23723:2021, Traditional Chinese medicine — General requirements for herbal raw material and
materia medica
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
Rheum root and rhizome
dried root and rhizome of Rheum palmatum Linne., Rheum tanguticum Maxim. ex Balf. and Rheum
officinale Baill
1
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ISO 5228:2023(E)
3.2
batch
samples collected from the same place at the same time, of no more than 5 000 kg
[SOURCE: ISO 22988:2020, 3.8]
4 Description
Rheum root and rhizome is the dried root and rhizome of Rheum palmatum Linne. (Figure 1 a), Rheum
tanguticum Maxim. ex Balf. (Figure 1 b) and Rheum officinale Baill. (Figure 1 c). The crude drug is
collected in late autumn when stem and leaves have withered or in spring just before budding. The
crude drug is removed from rootlet and the outer bark, cut into segments or sections and either hung in
line for drying or dried directly.
a) Rheum palmatum Linne.
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ISO 5228:2023(E)
b) Rheum tanguticum Maxim. ex Balf.
c) Rheum officinale Baill.
Key
1 inflorescence 5 leaf
2 flower 6 xylem, cambium and phloem
3 stem 7 pith
4 root and rhizome 8 abnormal vascular bundles
Figure 1 — Structure of Rheum root and rhizome
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ISO 5228:2023(E)
5 Requirements
5.1 General characteristics
The following requirements shall be met before sampling:
a) Rheum root and rhizome shall be clean and free from leaf and foreign matter.
b) The presence of living insects, mouldy fruit and external contaminants which are visible to the
naked eye shall not be permitted.
5.2 Morphological features
The medicinal materials of rheum root and rhizome are subcylindrical, conical, ovoid or irregular pieces,
3 cm to 17 cm long and 3 cm to 10 cm in diameter. Externally, they are yellowish-brown to reddish-
brown when peeled, sometimes with whitish reticulations and visible scattered star spots (abnormal
vascular bundles), occasionally with brownish-black patches of cork, mainly with a hole through which
the string is passed and coarse wrinkles. The texture of the medicinal parts is firm, sometimes loose
and soft in the centre, the facture pale reddish-brown or yellowish-brown and granular. The pith of the
rhizome is broad, with star spots arranged in a ring or irregularly scattered. The wood of the root is
well developed, lined radially, the cambium ring distinct and without star spots. The odour is delicately
aromatic, the taste bitter and slightly astringent. It is sticky and gritty to chew.
NOTE The hole and the string are for hanging Rheum root and rhizome when dry.
5.3 Identification
5.3.1 Microscopic identification
Transverse section of Rheum palmatum Linne. (Figure 2 a), Rheum tanguticum Maxim. ex Balf. (Figure 2 b)
and Rheum officinale Baill. (Figure 2 c): the cork and phelloderm of root are mostly removed. In phloem,
the sieve tube groups are distinct and the parenchyma is well developed. The cambium forms a ring.
Xylem rays are relatively dense, two to four rows of cells wide, containing brown masses. The vessels
are non-lignified, usually single or several grouped together and sparsely arranged. Parenchymatous
cells contain clusters of calcium oxalate and abundant starch granules.
The rhizome pith is broad, usually showing mucilage cavities and containing reddish-brown masses,
scattered with abnormal vascular bundles. The cambium forms a ring. Xylem is on the inside of the
cambium and phloem on the outside. Rays are stellate.
The powder is yellowish-brown. Clusters of calcium oxalate are 20 μm to 160 μm in diameter, sometimes
up to 190 μm in diameter. Bordered pitted vessels, reticulated vessels, spiral vessels and annular
vessels are non-lignified. Starch granules are abundant, single granules are spheroid or polygonal, 3 μm
to 45 μm in diameter, and hilum is stellate. The compound granules consist of two to eight components.
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ISO 5228:2023(E)
a) Rheum palmatum Linne. b) Rheum tanguticum Maxim. ex c) Rheum officinale Baill.
Balf.
Key
1 cork
2 cortex
3 phloem
4 cambium
5 xylem
6 pith
7 abnormal vascular bundles
a
Clusters of calcium oxalate.
b
Mucilage cavities.
Figure 2 — Transverse section of Rheum root and rhizome
5.3.2 Thin-layer chromatography (TLC) identification
Spots in the chromatogram obtained with the test solution should correspond in position and colour to
the spots in the chromatogram obtained from the reference drug solution or reference solution.
5.4 Rhaponticin
a) The bright-blue fluorescence spot in the chromatogram obtained with the test solution shall not
correspond in position and colour to the spot in the chromatogram obtained with the reference
solution TLC chromatogram.
b) When high-performance liquid chromatography (HPLC) is performed, the chromatographic peak of
the test solution shall not correspond at the retention time to the rhaponticin (C H O ) chemical
21 24 9
reference standard (CRS) of the HPLC chromatogram.
5.5 Moisture
The content of water should be a mass fraction of 15,0 %.
5.6 Total ash
The content of total ash should be a mass fraction of ≤ 13,0 %.
5
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ISO 5228:2023(E)
5.7 Acid-insoluble ash
The content of acid-insoluble ash should be a mass fraction of ≤ 2,0 %.
5.8 Extractives
The content of water-soluble extractives should be a mass fraction of ≥ 25,0 %.
5.9 Heavy metals
The contents of heavy metals, such as arsenic, mercury, lead and cadmium, shall be determined.
5.10 Pesticide residues
The contents of pesticide residues shall be determined.
5.11 Marker compounds
The contents of marker compounds, such as total anthraquinone, free anthraquinone and sennoside A,
shall be determined.
6 Sampling
Sampling shall be carried out in accordance with the method described in ISO 23723:2021, Clause 8.
7 Test methods
7.1 Macroscopic identification
Samples of not less than 500 g are taken from each batch randomly. These samples are examined by
the naked eye in sunlight and for smell. The ultra-performance liquid chromatography (UPLC) method
specified in Annex D is used to distinguish the three species of Rheum root and rhizome.
7.2 Thin-layer chromatogram (TLC) identification
See Clause A.1 for additional information.
7.3 Rhaponticin identification
See Clause A.2 and Clause B.4 for additional information. If the results of the two methods are
inconsistent, TLC shall prevail.
7.4 Determination of moisture
The testing method specified in ISO 23723: 2021, 7.2.1 applies.
7.5 Determination of total ash
The testing method specified in ISO 23723: 2021, 7.2.3 applies.
7.6 Determination of acid-insoluble ash
The testing method specified in ISO 23723: 2021, 7.2.3 applies.
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ISO 5228:2023(E)
7.7 Determination of extractives
The testing method specified in ISO 23723:2021, 7.2.5 applies.
7.8 Determination of heavy metals
The testing method specified in ISO 18664 applies.
7.9 Determination of pesticide residues
The testing method specified in ISO 22258 applies.
7.10 Determination of marker compounds
See Clauses B.1, B.2 and B.3 for additional information.
8 Test report
For each test method, the test report shall specify the following:
a) all information necessary for the complete identification of the sample;
b) the sampling method used;
c) the test method used, with reference to this document, i.e. ISO 5228:2023;
d) the test result(s) obtained;
e) all operating details not specified in this document or regarded as optional, together with details of
any incidents which could have influenced the test result(s);
f) any unusual features (anomalies) observed during the test;
g) the date of the test.
9 Packaging, storage and transportation
The packaging and transportation shall not transmit any odour or flavour to the product and shall not
contain substances that could damage the product or constitute a health risk. The packaging shall be
strong enough to withstand normal handling and transportation.
The storage condition specified in ISO 22217:2020, 5.2.1 shall apply.
The products shall be protected from light, moisture, pollution and foreign substances during long-
distance delivery. Carriers should be well ventilated so they remain dry and moisture-proof.
10 Marking and labelling
The method specified in ISO 21371 shall apply. The following items shall be marked or labelled on the
packages:
a) all quality features indicated in Clause 5, determined in accordance with methods specified in
Clause 7;
b) gross weight and net weight of the package;
c) country, province or state of origin of the products;
d) date of production and expiry date of the products;
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ISO 5228:2023(E)
e) storage method;
f) any items required by the destination.
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ISO 5228:2023(E)
Annex A
(informative)
Thin-layer chromatography (TLC) identification
A.1 TLC identification of Rheum root and rhizome
a) Macerate 0,1 g of the powder in 20 ml of methanol for 1 h and gravity filter. Evaporate 5 ml of
the filtrate to dryness, dissolve the residue in 10 ml of water, add 1 ml of hydrochloric acid, heat
under reflux on a water bath for 30 min and cool immediately. Extract by shaking with 20 ml of
ether twice, combine the ether extracts, evaporate to dryness and dissolve the residue in 1 ml of
chloroform as the test solution.
b) Prepare a solution of Rheum root and rhizome reference drug in the same manner as the reference
drug solution.
c) Dissolve rhein CRS in methanol to produce a solution containing 1 mg/ml as the reference solution.
d) Use the upper layer of a mixture of petroleum ether (30 °C to 60 °C), ethyl formate and formic acid
(15:5:1) as the mobile phase.
e) Use silica gel H mixed with sodium carboxymethylcellulose as the coating substance and apply 4 μl
each of the test solution, the reference drug solution and the reference solution to the plate. After
developing and removing the plate, dry in air and examine under ultraviolet light at 365 nm.
f) The five orange fluorescent spots in the chromatogram obtained with the test solution correspond
in position and colour to the spots in the chromatogram obtained with the reference drug solution.
The spot becomes red on exposure to ammonia vapour.
A.2 TLC identification of rhaponticin
a) Take 0,1 g of the powder, add 10 ml of methanol, ultrasonicate for 20 minutes and filter. Take 1 ml
filtrate and add methanol to 10 ml as the test solution.
b) Dissolve rhaponticin CRS in methanol to produce a solution containing 10 μg/ml as the reference
solution (freshly prepared).
c) Use a mixture of toluene, ethyl formate, acetone, methanol and formic acid (30:5:5:20:0,1) as the
mobile phase.
d) Use polyamide as the coating substance and apply separately to the film 5 μl each of the test solution
and the reference solution. After developing and removing the film, dry in air and examine under
ultraviolet light at 365 nm.
e) The bright-blue fluorescence spot in the chromatogram obtained with the test solution shall not
correspond in position and colour to the spot in the chromatogram obtained with the reference
solution.
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ISO 5228:2023(E)
Annex B
(informative)
Determination of marker compounds by HPLC-UV
B.1 Determination of total anthraquinone
B.1.1 Preparation of test solution
Weigh accurately 0,15 g of the powder (through no. 4 sieve) to a stoppered conical flask, accurately add
25 ml of methanol and weigh. Heat under reflux on a water bath for 1 h, cool, weigh again, replenish
the loss of solvent with methanol, mix well and filter. Measure accurately 5 ml of successive filtrate
in a flask, evaporate the solvent, add 10 ml 8 % solution of hydrochloric acid, ultrasonicate for 2 min
and add 10 ml of chloroform. Heat under reflux for 1 h, cool, transfer to a separating funnel, wash the
flask with a small quantity of chloroform and combine the washings to the separating funnel. Separate
the chloroform layer, extract the acid solution again with 10 ml of chloroform three times, combine
the chloroform extracts and recover the chloroform in a vacuum to dryness. Dissolve the residue in
methanol and transfer to a 10 ml volumetric flask, dilute with methanol to volume and mix well as the
test solution.
B.1.2 Prepara
...
DRAFT INTERNATIONAL STANDARD
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Traditional Chinese Medicine — Rheum palmatum, Rheum
tanguticum, and Rheum officinale root and rhizome
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STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
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RECIPIENTS OF THIS DRAFT ARE INVITED
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ISO/DIS 5228:2022(E)
DRAFT INTERNATIONAL STANDARD
ISO/DIS 5228
ISO/TC 249 Secretariat: SAC
Voting begins on: Voting terminates on:
Traditional Chinese Medicine — Rheum palmatum, Rheum
tanguticum, and Rheum officinale root and rhizome
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© ISO 2022
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NOT BE REFERRED TO AS AN INTERNATIONAL
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on STANDARD UNTIL PUBLISHED AS SUCH.
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IN ADDITION TO THEIR EVALUATION AS
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TECHNOLOGICAL, COMMERCIAL AND
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POTENTIAL TO BECOME STANDARDS TO
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WHICH REFERENCE MAY BE MADE IN
Reference number
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NATIONAL REGULATIONS.
Website: www.iso.org ISO/DIS 5228:2022(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
Published in Switzerland
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
ii
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PROVIDE SUPPORTING DOCUMENTATION. © ISO 2022
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ISO/DIS 5228:2022(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Description . .2
5 Requirements . 4
5.1 General characteristics . 4
5.2 Morphological features . 4
5.3 Identification . 4
5.3.1 Microscopic identification . . 4
5.3.2 Thin-layer chromatogram (TLC) identification . 5
5.4 Rhaponticin . 5
5.5 Moisture . 5
5.6 Total ash . 5
5.7 Acid-insoluble ash . 6
5.8 Extractives . 6
5.9 Heavy metals . 6
5.10 Pesticide residues . 6
5.11 Marker compounds . 6
6 Sampling . 6
7 Test methods . 6
7.1 Macroscopic identification . 6
7.2 Thin-layer chromatogram (TLC) identification . 6
7.3 Rhaponticin identification . 6
7.4 Determination of moisture . 6
7.5 Determination of total ash . 6
7.6 Determination of acid-insoluble ash . 6
7.7 Determination of extractives . 7
7.8 Determination of heavy metals . 7
7.9 Determination of pesticide residues . 7
7.10 Determination of marker compounds . 7
8 Test report . 7
9 Packaging, storage and transportation . 7
10 Marking and labelling . 7
Annex A (informative) Thin-layer chromatogram (TLC) identification . 9
Annex B (informative) Determination of marker compounds by HPLC-UV .10
Annex C (informative) Reference information of national and regional requirements .17
Annex D (informative) Differentiation of the three species .19
Bibliography .22
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ISO/DIS 5228:2022(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 249, Traditional Chinese medicine.
Any feedback or questions on this document should be directed to the user's national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
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Introduction
Rheum root and rhizome is the dry root and rhizome of Rheum palmatum L., Rheum tanguticum Maxim.
ex Balf. and Rheum officinale Baill. As one of the four traditional Chinese medicines in China, Rheum
root and rhizome is documented in Shennong material medica (神农本草经). Rheum root and rhizome
has a wide range of clinical applications, high frequency of use, and a long history of medicinal use. It is
recorded in traditional Chinese medicine books such as Yao pin hua yi(药品化义), Yi xue zhong zhong can
xi lu(医学衷中参西录)and Su Wen(素问).
Rheum root and rhizome has a cold property and bitter flavour. Its meridian distribution in the theory
of TCM belongs to the spleen, stomach, large intestine, liver, and pericardium meridians. It can remove
accumulation with purgation, clear heat, purge fire, cool the blood, remove toxin, expel stasis, unblock
the meridians, and drain dampness to abate jaundice, for accumulation, stagnation and constipation
caused by excess heat, hematemesis caused by intestinal abscess, blood-stasis amenorrhea, postpartum
stasis and obstruction, traumatic injuries, dampness-heat dysentery, jaundice, red urine, stranguria,
and edema, topical application for burn and scald. Wine-fried Rheum root and rhizome is good at
clearing heat toxin in the upper energizer blood aspect, which can be applied for red eyes, swollen
throat, and painful swollen gums. The purgation power of prepared Rheum root and rhizome is mild,
and it can purge fire and remove toxins to treat soreness and ulcers caused by fire-toxin. Charred
Rheum root and rhizome can cool the blood, resolve stasis and stop bleeding, which can be applied to
bleeding symptoms caused by blood heat and stasis.
Rheum root and rhizome has a complex chemical composition, including various compounds such as
anthraquinone, anthrone, tannin, and polysaccharide. Modern pharmacological studies have shown
that sennoside and anthraquinone glucosides are the main components of Rheum root and rhizome
that can induce diarrhea; free anthraquinones are antibacterial and antitumor active ingredients of
Rheum root and rhizome; n-butyrophenones have good anti-inflammatory and analgesic effects;
gallic acid glucosides and galloyl proanthocyanidins in the tannins have hypolipidemic effects; and
d-catechin and gallic acid have haemostatic effects. Moreover, Rheum root and rhizome also has the
functions of relieving phlegm, protecting the liver and gallbladder, and protecting cardiovascular and
cerebrovascular diseases.
In global trade, taking China Customs data as an example, Rheum root and rhizome in China is mainly
exported to Japan, South Korea, the United States, Indonesia, Germany, Italy, Singapore, France,
Thailand, Vietnam, Malaysia and so on. From 2012 to 2016, the average annual export trade volume
of Rheum root and rhizome in China was 7.128.400 US dollars, which is one of the main Chinese herbal
medicines exported by China.
There are 152 Chinese patent medicines containing Rheum root and rhizome in the Chinese
Pharmacopoeia (2015 Edition) and 2 preparations in Japanese Pharmacopoeia (17th Edition). Rheum
root and rhizome and its products have applications in a variety of medical fields, and also involve
detoxification and beauty, lipid-lowering, weight-loss health products and food additives. Many
users believe that "Chinese medicine is non-toxic" and fail to take it strictly according to the doctor's
instructions, which leads to excessive and chronic irregular use of Rheum root and rhizome and liver
and kidney damage.
As a worldwide drug, Rheum root and rhizome is included in the pharmacopoeia of many countries
and regions, such as China, Japan, Korea, and Europe. At present, the quality control of Rheum root and
rhizome and its preparations is mostly based on the content of anthraquinones. However, the medicinal
ingredients of Rheum root and rhizome are not just anthraquinones. The diversity of ingredients in
traditional Chinese medicine determines that quality control should adopt a multi-index quality
evaluation model.
Furthermore, Rheum root and rhizome is ranked tenth in the ISO/TR 23975: 2019 Traditional Chinese
medicine — Priority list of single herbal medicines for developing standards, which indicates its high
priority. Therefore, it is necessary to establish an international standard of Rheum root and rhizome,
which unifies the quality and safety of Rheum root and rhizome, ensures the safety and effectiveness of
the medication, and regulates trade in the international market. The establishment of an international
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ISO/DIS 5228:2022(E)
standard for Rheum root and rhizome is therefore necessary to guarantee the clinical effectiveness,
safety, and controllability of this valuable medicine in global commerce and trade.
As national implementation may differ, national standards bodies are invited to modify the values given
in 5.5, 5.6, 5.7, 5.8, 5.9, 5.10, and 5.11 in their national standards. Examples of national and regional
values are given in Annex C.
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DRAFT INTERNATIONAL STANDARD ISO/DIS 5228:2022(E)
Traditional Chinese Medicine — Rheum palmatum, Rheum
tanguticum, and Rheum officinale root and rhizome
1 Scope
This document specifies the quality and safety requirements of Rheum root and rhizome [the dried root
and rhizome of Rheum palmatum L., Rheum tanguticum Maxim. ex Balf., and Rheum officinale Baill.].
This document applies to Rheum root and rhizome that is sold and used as natural medicines in
international trade, including Chinese materia medica (whole medicinal materials) and decoction
pieces derived from these plants.
This document does not apply to the processing methods and processed products of Rheum root and
rhizome.
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 21371, Traditional Chinese medicine — Labelling requirements of products intended for oral or topical
use
ISO 22217, Traditional Chinese medicine —Storage requirements for raw materials and decoction pieces
ISO 22258, Traditional Chinese medicine — Determination of pesticide residues in natural products by gas
chromatography
ISO 23723, Traditional Chinese medicine — General requirements for herbal raw material and materia
medica
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological 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
Rheum root and rhizome
dried root and rhizome of Rheum palmatum L., Rheum tanguticum Maxim. ex Balf., and Rheum officinale
Baill.
3.2
batch
samples collected from the same particular place at the same time, no more than 5 000 kg
[SOURCE: ISO 22988:2019, 3.8]
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4 Description
Rheum root and rhizome is the dried root and rhizome of Rheum palmatum L., Rheum tanguticum Maxim.
ex Balf., and Rheum officinale Baill., as shown in Figure 1. The crude drug is collected in late autumn
when stem and leaves have withered or in spring just before budding. The crude drug is removed
from rootlet and the outer bark, cut into segment or section, and either hung in line for drying or dried
directly.
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Key
A rheum palmatum L.
B rheum tanguticum Maxim. ex Balf.
C rheum officinale Baill.
1 inflorescence
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2 flower
3 stem
4 root and rhizome
5 leaf
6 xylem, cambium and phloem
7 pith
8 abnormal vascular bundles
Figure 1 — Structure of Rheum root and rhizome
5 Requirements
5.1 General characteristics
The following requirements shall be met before sampling.
a) Rheum root and rhizome shall be clean and free from leave and foreign matter.
b) The presence of living insects, mouldy fruit, and external contaminants which are visible to the
naked eye shall not be permitted.
5.2 Morphological features
The appearance of the medicinal materials of rheum root and rhizome is subcylindrical, conical,
ovoid, or irregular pieces, 3 cm to 17 cm long, 3 cm to 10 cm in diameter. Externally yellowish-brown
to reddish-brown when peeled, sometimes whitish reticulations and scattered star spots (abnormal
vascular bundles) visible, occasionally with brownish-black patches of cork, mainly with a hole through
which the string passed, and coarse wrinkles. The texture is compact and sometimes loose and soft in
the center, facture pale reddish-brown or yellowish-brown, granular. The pith of the rhizome broad,
with star spots arranged in a ring or irregularly scattered. The wood of the root is well developed, lined
radially, cambium ring distinct, without star spots. Odour, delicately aromatic; taste bitter and slightly
astringent, sticky, and gritty on chewing.
NOTE The hole and the string are for hanging Rheum root and rhizome when dry.
5.3 Identification
5.3.1 Microscopic identification
Transverse section, as shown in Figure 2: most cork and phelloderm of root removed. In phloem, sieve
tube groups distinct, parenchyma well developed. Cambium in a ring. Xylem with relatively dense rays,
2 to 4 cells wide containing brown masses; vessels non-lignified, usually single or several grouped,
sparsely arranged. Parenchymatous cells have clusters of calcium oxalate and abundant starch granules.
The pith of the rhizome is broad, usually showing mucilage cavities, containing reddish-brown masses;
abnormal vascular bundles are scattered; cambium is in a ring; xylem is at the inside of cambium, and
phloem is outside. Stellate rays radiate.
Powder: Yellowish-brown. Clusters of calcium oxalate are 20 μm to 160 μm, sometimes up to 190 μm
in diameter. Bordered pitted vessels, reticulated vessels, spiral vessels, and annular vessels are non-
lignified. Starch granules are fairly abundant, single granules are spheroid or polygonal, 3 μm to 45 μm
in diameter, and hilum stellate; compound granules consist of 2 to 8 components.
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Key
A rheum palmatum L.
B rheum tanguticum Maxim. ex Balf.
C rheum officinale Baill.
1 cork
2 cortex
3 phloem
4 cambium
5 xylem
6 pith
7 abnormal vascular bundles
a clusters of calcium oxalate
b mucilage cavities
Figure 2 — Transverse section of Rheum root and rhizome
5.3.2 Thin-layer chromatogram (TLC) identification
Spots in the chromatogram obtained with the test solution should correspond in position and colour to
the spots in the chromatogram obtained from the reference drug solution or reference solution.
5.4 Rhaponticin
a) The bright blue fluorescence spot in the chromatogram obtained with the test solution shall not
correspond in position and colour to the spot in the chromatogram obtained with the reference
solution in TLC chromatogram.
b) When HPLC is performed, the chromatographic peak of the test solution shall not correspond
at the retention time to rhaponticin (C H O ) Chemical Reference Standard (CRS) in HPLC
21 24 9
chromatogram.
5.5 Moisture
The content of water in percentage mass should not be more than 15,0 % (w/w).
5.6 Total ash
The content of total ash in percentage mass should not be more than 13,0 % (w/w).
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5.7 Acid-insoluble ash
The content of acid-insoluble ash in percentage mass should not be more than 2,0 % (w/w).
5.8 Extractives
The content of water-soluble extractives in percentage mass should not be less than 25,0 % (w/w).
5.9 Heavy metals
The contents of heavy metals, such as arsenic, mercury, lead, and cadmium, shall be determined.
5.10 Pesticide residues
The contents of pesticide residues shall be determined.
5.11 Marker compounds
The content of marker compounds, such as total anthraquinone, free anthraquinone, and sennoside A,
shall be determined.
6 Sampling
Sampling shall be carried out in accordance with the method described in the Clause 8 of ISO 23723.
7 Test methods
7.1 Macroscopic identification
Samples not less than 500 g are taken from each batch randomly. These samples are examined by naked
eyes observation in sunlight, and smell. The UPLC method specified in Annex D was used to distinguish
the three species of Rheum root and rhizome.
7.2 Thin-layer chromatogram (TLC) identification
See Annex A.1 for additional information.
7.3 Rhaponticin identification
See Annex A.2 and Annex C.4 for additional information. If the results of the two methods are
inconsistent, TLC shall prevail.
7.4 Determination of moisture
The testing method specified in the Clause 7.2.1 of ISO 23723 applies.
7.5 Determination of total ash
The testing method specified in the Clause 7.2.3 of ISO 23723 applies.
7.6 Determination of acid-insoluble ash
The testing method specified in the Clause 7.2.3 of ISO 23723 applies.
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7.7 Determination of extractives
The testing method specified in the Clause 7.2.5 of ISO 23723 applies.
7.8 Determination of heavy metals
The testing method specified in ISO 18664 applies.
7.9 Determination of pesticide residues
The testing method specified in ISO 22258 applies.
7.10 Determination of marker compounds
See Annex C for additional information.
8 Test report
For each test method, the test report shall specify the following:
a) all information necessary for the complete identification of the sample;
b) the sampling method used;
c) the test method used, with reference to this international standard;
d) the test result(s) obtained;
e) all operating details not specified in this international standard, or regarded as optional, together
with details of any incidents which may have influenced the test result(s);
f) any unusual features (anomalies) observed during the test;
g) the date of the test.
9 Packaging, storage and transportation
The packaging and transportation shall not transmit any odour or flavour to the product and shall not
contain substances that may damage the product or constitute a health risk. The packaging shall be
strong enough to withstand normal handling and transportation.
The storage condition specified in the Clause 5.2.1 of ISO 22217 shall apply.
The products shall be protected from light, moisture, pollution, and foreign substances entry during
long-distance delivery. Carriers should be well ventilated to keep dry and moisture-proof.
10 Marking and labelling
See the method specified in ISO 21371. The following items shall be marked or labelled on the packages:
a) all quality features indicated in Clause 5, determined in accordance with methods specified in
Clause 7;
b) gross weight and net weight of the package;
c) country of origin and province/state of the products;
d) date of production and expiry date of the products;
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e) storage method;
f) any items required by regulatory bodies of the destination country.
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Annex A
(informative)
Thin-layer chromatogram (TLC) identification
A.1 TLC identification of Rheum root and rhizome
a) Macerate 0,1 g of the powder in 20 ml of methanol for 1 hour, and gravity filter. Evaporate 5 ml of
the filtrate to dryness, dissolve the residue in 10 ml of water, add 1 ml of hydrochloric acid, heat
under reflux on a water bath for 30 minutes and cool immediately. Extract by shaking with 20 ml
of ether twice, combine the ether extracts, evaporate to dryness and dissolve the residue in 1 ml of
chloroform as the test solution;
b) Prepare a solution of Rheum root and rhizome reference drug in the same manner as the reference
drug solution;
c) Dissolve rhein CRS in methanol to produce a solution containing 1 mg per ml as the reference
solution;
d) Use the upper layer of a mixture
...
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