Appendix XI D. Foreign Matter

Herbal drugs should be free from moulds, insects and other animal contamination.

Foreign matter is material consisting of any or all of the following:

1) foreign organs: matter coming from the source plant but not defined as the herbal drug;

2) foreign elements: matter not coming from the source plant and of either vegetable or mineral origin.

Dried plants

Sampling and sample preparation

Apply general chapter 2.8.20. Herbal drugs: sampling and sample preparation.

Determination of foreign matter

Weigh 100-500 g of the sample, or the minimum quantity prescribed in the individual monograph, and spread it out in a thin layer. Examine for foreign matter by inspection with the unaided eye or by use of a lens (6 ×). Separate foreign matter, weigh it and calculate the percentage present.

Fresh plants

Where general chapter 2.8.20. Herbal drugs: sampling and sample preparation cannot be applied, use one of the following methods, as appropriate: use method A when the test can be carried out on the whole batch; use method B when the test cannot be carried on the whole batch.

METHOD A

Sampling and sample preparation

Carry out the test on the whole batch.

Determination of foreign matter

Spread the batch out in a thin layer and examine for foreign matter by inspection with the unaided eye or by use of a lens (6 ×). Separate foreign matter, weigh it and calculate the percentage present.

METHOD B

Sampling and sample preparation

If it is not possible to inspect the whole batch, proceed as follows.

Bulk sample Prepare the bulk sample as described in general chapter 2.8.20. Herbal drugs: sampling and sample preparation.

Test sample Use the bulk sample or, where the bulk sample is greater than 1 kg, reduce it to a mass of 500-1000 g by a suitable method which retains the representative nature of the bulk sample.

Determination of foreign matter

Use the sample, or the minimum quantity prescribed in the individual monograph, and spread it out in a thin layer. Examine for foreign matter by inspection with the unaided eye or by use of a lens (6 ×). Separate foreign matter, weigh it and calculate the percentage present.