Priority should be given to ensuring that the available drugs have been made according to good manufacturing practices (21, Annex 1) and are of generally recognized quality. This requires knowledge of and confidence in the origin of the product. The risks of procuring drugs from anonymous sources cannot be over stressed. It is recommended that drugs be purchased directly from known manufacturers, their duly accredited agents or recognized international agencies known to apply high standards in selecting their suppliers.

Quality assurance of drugs, as embodied in product development, good manufacturing practice and subsequent monitoring of quality throughout the distribution chain to utilization, is a crucial element in any essential drug programme. The Committee wished to high-light the importance of the bioavailability of drugs in the assessment of their quality. All aspects of these procedures have been dealt with at length in the twenty-sixth to thirty-fifth reports of the WHO Expert Committee on Specifications for Pharmaceutical Preparations (21-30).