Quality Assurance of Pharmaceuticals - A Compendium of Guidelines and Related Materials - Volume 1
(1997; 248 pages) [French] View the PDF document
Table of Contents
Open this folder and view contentsIntroduction
Open this folder and view contents1. National drug regulation
Open this folder and view contents2. Product assessment and registration
Open this folder and view contents3. Distribution
Open this folder and view contents4. The international pharmacopoeia and related activities
Open this folder and view contents5. Basic tests
Close this folder6. Laboratory services
Open this folder and view contentsNational laboratories for drug quality surveillance and control1
Open this folder and view contentsGood laboratory practices in governmental drug control laboratories1
Close this folderSampling procedure for industrially manufactured pharmaceuticals1
Open this folder and view contents1. General considerations
Open this folder and view contents2. Use of terms
View the document3. General precautions to be taken during sampling operations
View the document4. Packaging and labelling of samples
View the document5. Sampling during pharmaceutical inspections
View the document6. Sampling of pharmaceutical dosage forms in regular surveillance programmes on drug quality during marketing
View the document7. Sampling of pharmaceutical dosage forms for acceptance of consignments
Close this folder8. Sampling of starting materials
View the document8.1 General considerations
View the document8.2 Sampling plans for consignments of starting materials supplied in several sampling units
Open this folder and view contents7. International trade in pharmaceuticals
Open this folder and view contents8. Counterfeit products
Open this folder and view contents9. Training
View the documentSelected WHO publications of related interest
View the documentBack cover
8.1 General considerations

Drug control laboratories are less frequently involved in the sampling of pharmaceutical starting materials, although they may be called upon to assess the quality of imported consignments. Again, this assessment must be undertaken using samples collected in accordance with an appropriate procedure, because a poorly collected sample may provide misleading information. The sampling procedure must have regard to whether or not the material can reasonably be considered as uniform. A more complex procedure must be employed when there is a suspicion of nonuniformity.

If the material of a consignment can be regarded as uniform, the sample can be taken from any part of the consignment. If, however, the material is not physically uniform, special sampling tools may be required to withdraw a cross-sectional portion of the material. In some instances, however, an attempt can be made to restore the uniformity of the material before sampling. Thus, a stratified liquid may be stirred, or a solid deposit in a liquid may be dissolved by gentle warming and stirring. Such interventions are difficult when the containers are large and they should not be attempted without adequate knowledge of the properties of the contents.

All partially processed natural products both herbal (dried plants and their parts) and mineral, should be treated as intrinsically nonuniform. Special procedures requiring considerable practice are used to prepare representative samples from such consignments, including coning and quartering and the treatment of fines. These procedures are not further described in these guidelines.1

1 Sampling procedures for crude natural products are given in several sources, such as: General control methods for vegetable drugs. Unpublished WHO document WHO/PHARM/80.502; The United States Pharmacopeia XXI, seventh supplement. Rockville, MD, The United States Pharmacopeial Convention Inc., 1988, p. 2859; [State Pharmacopoeia of the Union of Soviet Socialist Republics], eleventh edition. Moscow, Medicina, 1987, pp. 267-274.

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