SC VII A. Traditional Herbal Medicines

Introduction

This Supplementary Chapter provides information to help the users of the British Pharmacopoeia gain a greater understanding of the process behind the elaboration of monographs for traditional herbal medicines.

Traditional Herbal Medicinal Products (THMP) are classed as medicines under Article 16a(1) of EU Directive 2001/83/EC, as amended by Directive 2004/24/EC. The publication of monographs is intended to provide objective and publicly available standards of quality. It is emphasised that, although the monographs provide standards for quality, the British Pharmacopoeia Commission has not assessed the safety or efficacy of the herbal medicines.

British Pharmacopoeia monographs for traditional herbal medicines are identified for development in accordance with criteria referred to in Supplementary Chapter III B, in particular the degree of use of a traditional herbal medicinal product.

Some commercially available samples of herbal materials are processed herbal drugs. Where the herbal material is used in the processed form, only the processed form is readily available as an item of commerce in Europe. Where the processed herbal drug is used and where it is possible to obtain authenticated reference herbal samples for both the unprocessed and the processed herbal materials, two separate monographs have been elaborated. Processing methods may have the ability to alter the physical characteristics and/or the chemical constituents of a herbal drug. The two types of monographs are distinguished by means of the monograph titles. Monographs for the processed herbal drug include a ‘Production statement’ providing information on the method of processing.

The ultimate aim is to ensure that the quality of the monographs for the unprocessed and processed herbal drugs is of an equivalent standard to those of established monographs for herbal drugs.

The herbal samples used for the development of the monographs are authenticated independently. Specific limit tests may be prescribed to detect potential contaminants in processed herbal drugs. Other than the monograph titles the quality of the monographs for traditional herbal medicines are the same as established pharmacopoeial monographs for herbal drugs.

Monograph Titles

For traditional herbal medicinal ingredients, the monograph title is usually a combination of the binomial name together with a description of use (see the paragraph below). A monograph carries the title of the herbal ingredient and any appropriate synonyms. Because of regional variations in names, spelling variations and the likelihood of existence of other established terms in the countries of origin, Anglicised versions of the traditional names, for example Pinyin names, Ayurvedic names and also Chinese and Ayurvedic symbols will not be included as monograph titles.

To distinguish between monographs for unprocessed and the processed herbal drug, the word ‘Processed’ is included in the relevant monograph title.

Control Methods

Where applicable, the control methods outlined below will be applied:

(1) macroscopical and microscopical descriptions and chemical/chromatographic tests for identification;

(2) tests for absence of any related species;

(3) microbial test to assure microbial quality;

(4) where appropriate, tests for inorganic impurities, pesticides, aflatoxins and heavy metals;

(5) where appropriate, non-specific purity tests, including extractive tests and sulfated ash;

(6) wherever possible, a method for assaying the active constituent(s) or suitable marker substance(s);

(7) when more than one species/subspecies of the same plant are included in the Definition, individual differences between the two are indicated where possible.

Macroscopical Description The macroscopical description includes those features that can be seen by the unaided eye or by the use of a hand lens.

Microscopical Description The microscopical description of the powdered herbal drug gives information on the diagnostic characters. Example micrographs are being introduced on the website of the British Pharmacopoeia (http://www.pharmacopoeia.com).

Chromatographic tests Diagrammatic representation of the TLC plate will be included in the monograph as an aid to identification of the various constituents.

Other tests In the tests for Acid-insoluble ash, Ash, Extractive soluble in ethanol, Loss on drying, Sulfated ash, Water, Water-soluble ash and Water-soluble extractive of herbal drugs, the calculations will be made with reference to the herbal drug that has not been specifically dried unless otherwise prescribed in the monograph. Samples used for the development of the monographs are free from moulds, insects, decay, animal matter and animal excreta. Unless otherwise prescribed the amount of foreign matter will not be more than 2% w/w. Microbial contamination is such that a traditional herbal medicinal product complies with the acceptance criteria for the stated route of administration as recommended in Appendix VII D and G.

Assay When determining the content of the active constituents or the suitable marker substances measurements are made with reference to the dried or anhydrous herbal drug.