A pilot study on quality of artesunate and amodiaquine tablets used in the fishing community of Tema, Ghana

Abstract

Background: The ineffectiveness of artesunate and amodiaquine tablets in malaria treatment remains a health burden to WHO and governments of malaria-endemic countries, including Ghana. The proliferation of illegitimate anti-malarial drugs and its use by patients is of primary concern to international and local drug regulatory agencies because such drugs are known to contribute to the development of the malaria-resistant parasites in humans. No data exist on quality of these drugs in the fishing village communities in Ghana although the villagers are likely users of such drugs. A pilot study on the quality of anti-malarial tablets in circulation during the major fishing season at a malarious fishing village located along the coast of Tema in southern Ghana was determined.

Methods: Blisterpacks of anti-malarial tablets were randomly sampled. The International Pharmacopoeia and Global Pharma Health Fund Minilab protocols were used to assess the quality of anti-malarial tablets per blisterpacks allegedly manufactured by Guilin Pharmaceutical Co Ltd, China (GPCL) and Letap Pharmaceuticals Ltd, Ghana (LPL) and sold in chemical sales outlets at Kpone-on-Sea. Ferric chloride and cobaltous thiocyanate tests confirmed the presence of active ingredients in the tablets. A confirmatory test for the active ingredient was achieved with artesunate (ICRS1409) and amodiaquine (ICRS0209) reference standards. A high performance liquid chromatography analysis confirmed the amount of artesunate found in tablets.

Results: Based on the International Pharmacopoeia acceptable range of 96/98 to 102% for genuine artesunate per tablet, 10% [relative standard deviation (RSD): 3.2%] of field-selected artesunate blisterpack per tablets manufactured by GPCL, and 50% (RSD: 5.1%) of a similar package per tablet by LPL, passed the titrimetric test. However, 100% (RSD: 2.2%) of amodiaquine blisterpack per tablet by GPCL were found to be within the International Pharmacopeia acceptable range of 90 to 110% for genuine amodiaquine in tablet, whilst 17% of a similar package per tablet by LPL failed spectrophotometric testing.

Conclusion: Inadequate amounts of artesunate and amodiaquine detected in the tablets suggest that both pharmaceutical companies may not be following recommended drug formulation procedures, or the active pharmaceutical ingredients might have been degraded by improper storage conditions. Thus, drugs being sold at Kpone-on-Sea, Ghana may likely be classified as substandard drugs and not suitable for malaria treatment.

Figure 1

GPS map of Kpone-On-Sea showing the locations of individual houses of the study area is a map of Ghana.

Figure 2

Titrimetric analysis of artesunate API in tablets from GPCL and LPL. Meaning of abbreviations: Artstd = artesunate reference standard; G1 to G10 = artesunate blisterpack by Guilin Pharmaceutical Co Ltd (n = 10); L1 to L6 = artesunate blister pack by Letap Pharmaceutical Ltd (n = 6); Total number of samples = 16.

Figure 3

Spectrophotometry analysis of amodiaquine API in tablets from GPCL and LPL. Meaning of abbreviations: Amdstd = amodiaquine reference standard; G1 to G10 = amodiaquine blister pack by Guilin Pharmaceutical Co Ltd (n = 10) L1 to L6 = amodiaquine blisterpack by Letap Pharmaceutical Ltd (n = 6); Total number of samples = 16.