(1997; 248 pages) [French]
National laboratories for drug quality surveillance and control
An independent drug quality control laboratory is an indispensable element of a national drug quality assurance system, and is particularly important nowadays in the light of infiltration of distribution channels by counterfeit products. Laboratories are still missing in many developing countries. The reason for this is partly that, in the absence of any guidance on the basic requirements for such a laboratory, it was assumed for a long time that the costs would be so exorbitant that it would be beyond the resources of most developing countries.
In its twenty-ninth report, the WHO Expert Committee on Specifications for Pharmaceutical Preparations stated that every country, regardless of its stage of development, should consider investment in an independent national drug quality control laboratory. The Expert Committee made recommendations directed to the many developing countries that have not yet created such a facility and do not have the resources to maintain a comprehensive system of control.
It should be recognized, in particular, that:
- simple procedures, such as tablet disintegration tests, are frequently of critical importance in eliminating seriously substandard preparations;
- a small laboratory directed by a competent, discerning individual will provide a persuasive deterrent to negligent or fraudulent manufacturing practices;
- the availability of complex automated equipment accelerates but does not necessarily raise the standard of analytical work. Moreover, such equipment performs reliably only when it is expertly maintained. Its operation may require the use of highly purified and expensive reagents.
Chapter 6 contains proposed models for a first-stage laboratory for drug surveillance, and a medium-size drug control laboratory. It provides advice on capabilities, premises, staff and equipment as well as on the scope of activities, factors influencing size and location of a laboratory, and the implementation of control laboratory projects. Even the smaller of the two model laboratories provides for the full pharmacopoeial analysis of more that 75% of WHO’s Model List of Essential Drugs in accordance with the methods provided for in The international pharmacopoeia.
A document containing current prices for laboratory equipment is regularly updated and is available on request from the Quality Assurance unit, Division of Drug Management and Policies, WHO, 1211 Geneva 27, Switzerland.
Good practices for quality control laboratories
To complement its advice on setting up governmental drug control laboratories, the WHO Expert Committee on Specifications for Pharmaceutical Preparations included in its thirtieth report guidelines on good practices in governmental drug control laboratories. These, reproduced in Chapter 6, deal with management and operational issues affecting governmental drug control laboratories which analyse products for registration or during post-marketing surveillance. The scope of the guidelines ranges from organizational structure and staffing to advice on routines and management, documentation requirements, and the evaluation of test results. The sections on analytical work are primarily concerned with chemical and physicochemical analyses rather than with microbiological, pharmacological or other specialized test methods. The practices outlined are not fully applicable to quality control laboratories in manufacturing establishments, where test procedures and documentation may be different.
The guidelines are intended to be illustrative rather than prescriptive and need to be adapted to differing local circumstances such as the size of the laboratory. Alternative approaches to management are acceptable, provided that reliability of operations remains assured. In small laboratories many of the responsibilities lie with one qualified analyst, but the principles of management and operation are the same.
Sampling procedure for industrially manufactured pharmaceuticals
Since analytical control procedures are often performed on only a small portion of the material under consideration, it is vital to ensure that the sample tested is reasonably representative of the whole batch or consignment. Many of the operations described in the guidelines on good laboratory practices in governmental drug control laboratories require the use of sound sampling procedures. It is for this reason that, in its thirty-first report, the WHO Expert Committee on Specifications for Pharmaceutical Preparations provided guidelines for sampling procedures for industrially manufactured pharmaceuticals. These are reproduced in Chapter 6.
No single sampling plan is applicable to all situations. Different considerations and methodologies apply to in-process control, to batch release by manufacturers, to routine control of consignments within the distribution chain, and to spot-sampling carried out by purchasers or government inspectors.
The guidelines on sampling procedures are intended primarily for use by national drug regulatory authorities and governmental procurement agencies, but the general principles and much of the advice are also applicable to manufacturers and wholesalers.