Aim: This was a pilot study to assess the quality of antimalarials (chloroquine and sulphadoxine/pyrimethamine) in selected African countries, and to determine whether the quality of these products was related to the level of the distribution chain at which the samples were collected.
Methods: Samples were collected systematically from seven participating countries that were coordinated by country team leaders. Each team leader was responsible for coordinating sample collection, coding and packaging for transportation to WHO/AFRO headquarters through the WHO country offices. The samples were then sent to a single contracted laboratory, the Centre for Quality Assessment of Medicines (CENQAM) in Potchefstroom, South Africa, for analysis.
Findings: The results identified several significant problems of substandard products within the drug distribution chains. They included percentage failures in ingredient content ranging from 20% to 67% for chloroquine tablet (CQT) and 5% to 38% for sulphadoxine/pyrimethamine tablet (SPT) and dissolution failures ranging from 5% to 29% for CQT and 75% to 100% for SPT. Such results cannot be ignored. In view of the potential danger that the substandard antimalarials could already be posing in the fight against malaria, an intervention plan should be developed immediately. For example, quality surveillance systems could be set up within drug regulatory authorities in the region and support given to manufacturers to improve compliance with good manufacturing practices (GMP).
The study faced a number of logistical difficulties. Of the eight participating countries, seven (Gabon, Ghana, Kenya, Mali, Mozambique, Sudan and Zimbabwe) submitted their samples in time for laboratory analysis. Some of the samples that were collected could not be analysed for various reasons, including spillage, crystallization of syrup samples, insufficient quantities and incorrect labelling.
No clear relationship between the quality of products and the level of the distribution chain was observed. Similarly, there was no difference between locally manufactured and imported products.
Conclusion and recommendations: The data from this pilot project indicate significant problems of substandard antimalarial products circulating within the drug distribution chains in the African region. This appears to be due to non-compliance with GMP guidelines by manufacturers in the production of the antimalarials. Additionally, the products evaluated in this study may also have been susceptible to handling problems, so rendering the observed patterns non conclusive. However, in view of the potential danger that the substandard antimalarials could already be posing in the region, there is justification for WHO’s Roll Back Malaria programme and others to take the necessary remedial measures to ensure access to good quality drug products. These measures should include support to national regulatory authorities in strengthening manufacturing and distribution channel inspections. Equally critical is the need for WHO to support regulatory authorities to work with the pharmaceutical manufacturers to improve compliance to GMP, and good procurement and distribution practices.