Herbal Drugs

(Ph. Eur. monograph 1433)

Herbal Drugs comply with the requirements of the European Pharmacopoeia. These requirements are reproduced below.

Ph Eur

Herbal drugs are mainly whole, fragmented, or broken plants, parts of plants, algae, fungi or lichen, in an unprocessed state, usually in dried form but sometimes fresh. Certain exudates that have not been subjected to a specific treatment are also considered to be herbal drugs. Herbal drugs are precisely defined by the botanical scientific name according to the binominal system (genus, species, variety and author).

Whole describes a herbal drug that has not been reduced in size and is presented, dried or undried, as harvested; for example: dog rose, bitter fennel or sweet fennel, Roman chamomile flower.

Fragmented describes a herbal drug that has been reduced in size after harvesting to permit ease of handling, drying and/or packaging; for example: cinchona bark, rhubarb, passion flower.

Broken describes a herbal drug in which the more-fragile parts of the plant have broken during drying, packaging or transportation; for example: belladonna leaf, matricaria flower, hop strobile.

Cut describes a herbal drug that has been reduced in size, other than by powdering, to the extent that the macroscopic description in the monograph of the herbal drug can no longer be applied. When a herbal drug is cut for a specific purpose that results in the cut herbal drug being homogeneous, for example when cut for herbal teas, it is a herbal drug preparation. Certain cut herbal drugs processed in this way may be the subject of an individual monograph.

A herbal drug that complies with its monograph and is subsequently cut for extraction shall comply in its cut form, except for its macroscopic description, with the monograph for that herbal drug, unless otherwise justified.

The term herbal drug is synonymous with the term herbal substance used in European Community legislation on herbal medicinal products.

Herbal drugs are obtained from cultivated or wild plants. Suitable collection, cultivation, harvesting, drying, fragmentation and storage conditions are essential to guarantee the quality of herbal drugs.

Herbal drugs are, as far as possible, free from impurities such as soil, dust, dirt and other contaminants such as fungal, insect and other animal contaminations. They are not rotten.

If a decontaminating treatment has been used, it is necessary to demonstrate that the constituents of the plant are not affected and that no harmful residues remain. The use of ethylene oxide is prohibited for the decontamination of herbal drugs.

Herbal drugs are identified using their macroscopic and microscopic descriptions and any further tests that may be required (for example, thin-layer chromatography).

Carry out a test for foreign matter, unless otherwise prescribed or justified and authorised. The content of foreign matter is not more than 2 per cent m/m, unless otherwise prescribed or justified and authorised. An appropriate specific test may apply to herbal drugs liable to be adulterated. It may not be possible to perform the test for foreign matter on a herbal drug that is cut, as described under Definition, for either a specific purpose or for extraction. Under these circumstances the cut material is presumed to comply with the test for foreign matter providing that the herbal drug prior to cutting was compliant with this test.

Carry out a test for loss on drying, unless otherwise prescribed or justified and authorised.

A determination of water may be carried out instead of a test for loss on drying for herbal drugs with a high essential-oil content.

Herbal drugs comply with the requirements for pesticide residues. The requirements take into account the nature of the plant, where necessary the preparation in which the plant might be used, and where available the knowledge of the complete record of treatment of the batch of the plant.

Unless otherwise stated in an individual monograph or unless otherwise justified and authorised:

• — cadmium: maximum 1.0 ppm;

• — lead: maximum 5.0 ppm;

• — mercury: maximum 0.1 ppm.

Where necessary, limits for other heavy metals may be required.

Where necessary herbal drugs comply with other tests, such as the following, for example.

Where necessary, limits for aflatoxins may be required.

Where necessary, a limit for ochratoxin A may be required.

In some specific circumstances, the risk of radioactive contamination is to be considered.

Where a herbal drug is used whole, cut or powdered as an ingredient in a medicinal product, the microbial contamination is controlled (Microbiological quality of herbal medicinal products for oral use (5.1.8) or Microbiological quality of non-sterile pharmaceutical preparations and substances for pharmaceutical use (5.1.4) (for example, for cutaneous use)).

Unless otherwise prescribed or justified and authorised, herbal drugs are assayed by an appropriate method.

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Ph Eur