Substandard antimalarials are believed to contribute to resistant Plasmodium falciparum, a protozoa parasite which causes malaria. The problem is particularly acute in sub-Saharan Africa countries, such as Senegal, Madagascar and Uganda.
These countries were the focus of the study by Promoting the Quality of Medicines (PQM), a programme implemented by the US Pharmacopeia (USP). Across the three countries 491 antimalarials underwent basic testing, with 197 being sent for full-scale quality-control.
Of the samples from Senegal 44 per cent were substandard. The situation was slightly better in Madagascar and Uganda, where the study found respectively that 30 per cent and 26 per cent of samples were substandard.
Failing the quality control test indicates the product either contains the wrong amount of active pharmaceutical ingredient (API), fails to dissolve properly or includes unacceptable levels of potentially harmful impurities. All the products tested contained some of the API.
Tackling substandard antimalarials
The study has provided regulators with information which can inform enforcement activities. For instance, a brand which failed in one country was likely to fail in another. This suggests that the quality shortcomings were created at the source, rather than during distribution.
Furthermore, the study gathered information about the distribution of poor quality medicines within a country. In Madagascar substandard medicines are widespread and sold by various distributors but the situation in Uganda is different.
Here the study found that all public sector medicines passed quality tests. This allows regulators in Uganda to focus efforts on the private sector, while maintaining its excellent record in public distribution.
The results from Uganda, Senegal and Madagascar are part of the ten-country Quality of Antimalarials in Sub-Saharan Africa (QAMSA) study. This is a collaborative effort between PQM and the World Health Organization (WHO).