Tropical diseases are a major public health problem in developing countries (Disease Endemic Countries – DECs). For many of these diseases no new, effective and affordable medicines have been developed, while older therapeutic agents are increasingly compromised by the emergence of resistance. Because multinational pharmaceutical companies have not traditionally focused on tropical disease research and development (R&D), WHO has initiated R&D programmes in a number of priority areas such as malaria. WHO’s Special Programme for Research and Training in Tropical diseases (TDR) commissions studies to be conducted in the geographical regions most affected by such diseases. If such R&D is to result in marketing approval of effective and safe new drug products, the component studies must comply with current research practice standards ensuring the quality, reliability and integrity of study data. Market authorisation regulations require that quality standards, i.e. Good Manufacturing Practice (GMP), Good Laboratory Practice (GLP) and Good Clinical Practice (GCP), are followed in the respective stages of the development and life-cycle of a drug product.

WHO published standards for Good Manufacturing Practice (GMP) in 1999 (covering the manufacture of a drug product) and Good Clinical Practice (GCP) in 1995 (covering clinical trials in man). However, until the publication of the first version of this handbook in 2001, WHO had not addressed quality standards for non-clinical testing for the safety of potential products : Good Laboratory Practice (GLP). This handbook, and its associated training volumes, specifically address this gap in WHO recommendations.

The introduction of GLP quality standards in test facilities of developing countries was seen as an urgent issue and, accordingly, WHO convened a working party (Scientific Working Group on GLP issues – SWG) in 1999 and 2000 to address the WHO position on GLP.

During the SWG discussions it became evident that, for test facilities in developing countries, the introduction of GLP could be impeded by resource constraints (e.g. few trained personnel, inadequate facilities and equipment) or by the instability of the infrastructure (e.g. water or electricity supply), either within the testing laboratory itself or in the community as a whole. However, GLP could result in tangible returns through the number of studies placed with research organisations in DECs, resulting in an overall increase in funding. It is clear that as funding is scarce sponsors will not invest in studies if the reliability of results cannot be assured. Specifically, WHO/TDR will be reluctant to allocate their limited funding to non-clinical safety studies unless the results can be reliable on and thus support decisions concerning the progress of products to clinical stages and eventually to product registration.

The deliberations of the Scientific Working Group on GLP issues underlined the following points:

• In DECs, demonstrating compliance with GLP will become a prerequisite for nonclinical safety testing and for drug registration particularly where drug products are projected for markets other than the country of origin;
• It is essential to avoid the co-existence of two or more international GLP regulatory standards for non-clinical safety testing;
• Guidance is needed for the implementation of GLP.

With such considerations in mind the SWG recommended that WHO/TDR adopt the Revised OECD Principles of Good Laboratory Practice as its official guidance for nonclinical safety testing. The handbook sets forth the OECD Principles in their original text, supplemented by sections on training and the implementation of GLP.