Substandard artemisinin-based antimalarial medicines in licensed retail pharmaceutical outlets in Ghana

The artemisinin-based antimalarial medicines are first line medicines in the treatment of severe and uncomplicated falciparum malaria. Numerous brands of these medicines manufactured in various countries are available in the Ghanaian market. The study was aimed at evaluating the authenticity and quality of selected brands of artemisinin-based antimalarial medicines marketed in Ghana.

In all, 14 artemisinin-based antimalarial medicines were purchased from pharmacies (P) and licensed chemical shops (LCSs) in the Kumasi metropolis, Ghana. Simple field tests based on colorimetry and thin layer chromatography were employed in determining the authenticity of the samples. Important quality assessment tests, namely uniformity of mass, crushing strength, disintegration time, and the percentage content of active pharmaceutical ingredients (APIs) were determined.

All the brands tested contained the stipulated APIs. Artesunate tablet AT2 failed the uniformity of mass test while artesunate tablets AT3 & AT4 as well as amodiaquine tablets AM4 & AM6 failed the crushing strength test. All the six artemether-lumefantrine tablet brands passed the uniformity of mass, crushing strength and disintegration tests. Only artemether-lumefantrine tablet brand AL1 contained the correct amount of the drugs. The other 13 artemisinin products contained either a lower (underdose) or higher (overdose) amount of the specified drug. Artesunate monotherapy tablets were readily available in pharmacies and licensed chemical shops.

All the artemisinin-based medicines tested (except AL1) were of substandard quality. The results demonstrate the need for continuous monitoring and evaluation of the quality of artemisininbased antimalarials in the Ghanaian market. Also, the practice of artemisinin antimalarial monotherapy is prevalent in Ghana. Determined efforts should, therefore, be made to eradicate the practice to prevent the development of resistance to the artemisinins.