Brazilian study gauges malaria drug quality

Brazilian researchers have found evidence of quality defects in a small sampling study designed to test the quality of antimalarial drugs held at national and state facilities, some of which cannot be explained by inadequate storage conditions.

The researchers wanted to gauge the quality of antimalarials held in Brazil's public health facilities in light of concerns over the emergence of drug resistance, which has been linked to counterfeit and substandard medicines.

They took samples of chloroquine, mefloquine, primaquine and quinine sulfate - which had been stored for five months - from a government-run central unit in Rio de Janeiro, state storerooms and basic health facilities in the north of Brazil. Inadequate storage facilities were uncovered in all the basic medical facilities and two of the state storage units, according to the study.

While the chloroquine samples were all of acceptable quality, they did find deviations with quinine samples - some of which were of variable weights - and packaging issues which could compromise the quality of primaquine samples.

The study did not include authentication of the samples, but the authors note that "the quality deviations found with the primaquine and quinine samples are not related to storage conditions" and need to be investigated further.

Meanwhile, mefloquine samples from the regional facilities had significantly different release profiles than those sampled from the centralised unit, indicating formulation problems or inadequate storage conditions.

On the plus side, the quality defects uncovered in the study are not likely to have contributed to malarial parasite resistance, according to the scientists.
 
"It is important to periodically evaluate the quality of essential drugs, mainly anti-infective ones, which, if substandard or counterfeit, pose a threat to patients and the public health, including the risk of selection of resistant parasites," they write.