Background: Malaria has always been a major public health problem in Yemen.
Several studies in developing countries have demonstrated ineffective and poor quality drugs
including antimalarials. Therefore, quality assessment of antimalarial drugs is of crucial importance.
This study aimed to assess the quality of antimalarials (chloroquine and sulfadoxine/pyrimethamine)
available in Yemen and to determine whether the quality of these products was related to the level
of the distribution chain at which the samples were collected or related to the manufacturers.
Methods: Four samples from each antimalarial product were collected from each
of the various levels of the distribution chain. One sample was kept with the research team.
Two were tested at Sana'a and Aden Drug Quality Control Laboratories. The fourth was sent to the
Centre for Quality Assurance of Medicines in Potchefstroom, South Africa, for analysis. Quality
indicators measured were the content of the active ingredient and dissolution rate (for tablets
only) in comparison to standard specifications for these products in the relevant pharmacopoeia.
Results: The results identified several problems of sub-standard products
within the drug distribution chain. They included high and low failures in ingredient content
for chloroquine tablets and chloroquine syrup. There was some dissolution failure for chloroquine
tablets, and high sulfadoxine/pyrimethamine tablets dissolution failures. Failures with the
dissolution of the pyrimethamine were found at most of the collection points. No clear relationship
neither between the quality products and the level of the distribution chain, nor between
locally manufactured and imported products was observed.
Conclusion: There are sub-standard antimalarial products circulating within
the drug distribution chains in the country, which will have serious implications on the reduced
therapeutic effectiveness and on the development of drug resistance. This appears to be due to
non-compliance with Good Manufacturing Practice guidelines by manufacturers in the production of the