WHO published Quality control methods for medicinal plant materials in 1998 in
order to support WHO Member States in establishing quality standards and
specifications for herbal materials, within the overall context of quality
assurance and control of herbal medicines. This is the updated edition of the
1998 publication, with an updated title.
The purpose of this updated edition remains unchanged from that of the first
edition. It is to support the development of national standards based on local
market conditions, with due regard to existing national legislation and national
and regional norms. It describes a series of internationally harmonized tests
for assessing the quality of herbal materials, including the determination of
pesticide residues, arsenic and toxic heavy metals, microorganisms and
A collection of recommended test procedures for assessing the identity, purity,
and content of herbal materials, intended to assist national laboratories
engaged in pharmaceutical quality control, the manual responds to the growing
use of herbal medicines, the special quality problems they pose, and the
corresponding need for international guidance on reliable methods for quality
control. Where relevant, suitable test apparatuses are illustrated and
The publication includes chapters that cover internationally harmonized
procedures for preparing culture media, strains of microorganisms suitable for
use in tests, specifications for adsorbents for use in thin-layer
chromatography, and detailed descriptions of the reagents, test solutions, and
volumetric solutions used in the recommended tests.
Recommended procedures - whether involving visual inspection or the use of
thin-layer chromatography for the qualitative determination of impurities -
should also prove useful to the pharmaceutical industry and pharmacists working
with herbal materials.
In order to promote good practices and to provide general technical guidance in
conducting the test methods described in this publication, WHO good practices
for pharmaceutical quality control laboratories is annexed to this publication
for easy reference. The scope of the good practice guidance includes
pharmaceutical laboratories handling herbal medicines, and an example of a list
of equipment for pharmacognosy/phytochemical laboratories is provided therein.
This new edition will continue to serve as key technical training material for
national capacity-building in setting standards for herbal medicines. This
publication is an example of the immediate response of WHO in the implementation
of the resolution on Global strategy and plan of action on public health,
innovation and intellectual property that was adopted by the Sixty-first World
Health Assembly in 2008.