Details of all the reference materials required should be kept in a central register. In a large laboratory this responsibility should be assigned to a specific person designated as the reference material coordinator. A national drug control laboratory that is required to establish reference materials for other institutions or for drug manufacturers will need to create a separate reference materials unit which will assume all the duties of the coordinator.
The register should contain details not only of all official reference substances and reference preparations, but also of secondary reference materials and non-official materials prepared in the laboratory as working standards. Each entry should be assigned a number and should give a precise description of the material, its source, the date of receipt, the batch designation or other identifying code, the intended use of the material (infrared reference material, impurity reference material for thin-layer chromatography, etc.), the place in the laboratory where it is stored, and any special storage conditions.
In addition to the register, a file should be kept containing full information on the properties of each reference material. In the case of working standards prepared in the laboratory the file should include the results of all tests and checks used to establish the standard and the initials of the responsible analyst.
Its laboratory identification number should be marked on each vial of the material and this must be quoted in the analytical worksheet every time it is used. A new number should be assigned to each new batch of material as soon as it is delivered or prepared. All reference materials should be inspected at regular intervals to make sure that they have not deteriorated and that they are being stored under appropriate conditions.
Further guidance on establishing, handling, and storing reference materials is contained in Annex 1 of the twenty-eighth report of this Committee (3).