By : World Health Organization (WHO)


A collection of recommended test procedures for assessing the identity, purity, and content of medicinal plant materials. Intended to assist national laboratories engaged in drug quality control, the manual responds to the growing use of medicinal plants, the special quality problems they pose, and the corresponding need for international guidance on reliable methods for quality control. 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 medicinal plant materials.
Test procedures are intended to support the development of national standards based on local market conditions, with due regard to existing national legislation and national and regional norms. The book also includes advice on general limits for pesticides and other contaminants commonly found in medicinal plant materials.
The book opens with a brief discussion of general principles for the analysis of plant materials, including advice on the special handling procedures required during sampling, and guidance on macroscopic and microscopic examination as the first step towards establishing the identity and degree of purity of plant materials. Subsequent chapters describe procedures for the determination of foreign matter, ash, extractable matter, water and volatile matter, volatile oils, bitterness value, haemolytic activity, tannins, swelling index, and foaming index. Where relevant, suitable test apparatuses are illustrated and explained.
Additional chapters set out test methods for the determination of such important contaminants as pesticide residues, arsenic and heavy metals, and microorganisms, including aflatoxins. The remaining chapters cover 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 volumeric solutions used in the recommended tests.