Use of thin-layer chromatography to detect counterfeit sulfadoxine/pyrimethamine tablets with the wrong active ingredient in Malawi.

Felix Khuluza,Lutz Heide,Richard W O Jähnke,Stephen Kigera

doi:10.1186/s12936-016-1259-9

Felix Khuluza, Lutz Heide + Show 2 more

Open Access

https://doi.org/10.1186/s12936-016-1259-9

Copy DOI

Journal: Malaria journal	Publication Date: Apr 14, 2016
Citations: 27	License type: cc-by

Affiliation: University of Tübingen, University of Malawi

Abstract

BackgroundSubstandard and falsified anti-malarial medicines pose a serious threat to public health, especially in low-income countries. Appropriate technologies for drug quality analysis in resource-limited settings are important for the surveillance of the formal and informal drug market. The feasibility of thin-layer chromatography (TLC) with different solvent systems was tested using the GPHF Minilab in a study of the quality of sulfadoxine/pyrimethamine tablets in Malawi.MethodsTwenty eight samples of sulfadoxine/pyrimethamine tablets were collected from randomly selected health facilities of four districts of southern Malawi. A mystery shopper approach was used when collecting samples from illegal street vendors, and an overt approach for the other facilities. Samples were subjected to visual inspection, disintegration testing and TLC analysis. 10 samples were further investigated according to the methods of the US Pharmacopeia using high performance liquid chromatography (HPLC).ResultsOne sample was found to be falsified, containing a mixture of paracetamol tablets and co-trimoxazole tablets. These had been repackaged into paper strip packs labelled as a brand of sulfadoxine/pyrimethamine. TLC with different solvent systems readily proved that these tablets did not comply with their declaration, and provided strong evidence for the active pharmaceutical ingredients which were actually contained. Full pharmacopeial analysis by HPLC confirmed the results suggested by TLC for this sample, and showed two further samples to be of substandard quality.ConclusionsDue to the absence of the declared anti-malarial ingredients and due to the presence of other pharmaceutical ingredients, the identified falsified medicine represents a serious health risk for the population. Thin-layer chromatography (TLC) using different solvent systems proved to be a powerful method for the identification of this type of counterfeiting, presenting a simple and affordable technology for use in resource-limited settings.

Highlights

Substandard and falsified anti-malarial medicines pose a serious threat to public health, especially in low-income countries
Out of 28 samples of sulfadoxine/pyrimethamine tablets collected in Malawi, one was found not to contain the declared active ingredients but to represent a mixture of paracetamol and co-trimoxazole tablets
This type of counterfeiting represents a serious risk to public health

Summary

Introduction

Substandard and falsified anti-malarial medicines pose a serious threat to public health, especially in low-income countries. The required instruments cost 50,000–100,000 $ (USA) for standard equipment, and more for advanced equipment [2] They are complicated and delicate mechanical and electronic tools, requiring careful handling by trained professionals as well as an infrastructure including an electricity supply of constant voltage, very pure organic solvents, and regular maintenance by skilled technicians. No capacity exists in such countries for the regular surveillance of drug quality on the various levels of the drug supply chain, thereby opening the possibility for substandard and falsified medicines to enter the market [3]

Methods

Results

Discussion

Conclusion