Evaluation of the quality of anti Tuberculosis drugs in Lusaka, Zambia

Abstract

Background: Counterfeit and substandard medicines are a threat to health and the risks they pose have been largely underestimated to date. Almost all areas of the world are affected by the availability of substandard and counterfeit medicines, but mounting evidence shows that the problem is disproportionately severe in developing and emerging market countries, which also have a high burden of infectious diseases. In poor countries, essential and life-saving drugs used to treat infectious diseases such as tuberculosis and malaria are often the drugs under threat.
Methodology: This was a cross sectional study whose objective was to determine the quality of 3 types of fixed dose combination (FDC) anti TB drugs namely 4FDC, 3FDC and 2FDC tablets available in Lusaka District by assessing the presence of active ingredients and the percentage content of these active ingredients according to the British pharmacopoeia 2008 using Spectrophotometric method. The drug samples analyzed had a shelf life of at least one year.
Results: For presence of active ingredient, all the seventeen samples that were tested gave a positive result indicating that each sample had the correct active ingredients as indicated by the label claim. However, 20% (1/5) of the 4FDC samples and 14% (1/7) of the 2FDC samples were none compliant to the BP 2008 specification for percentage content. One sample of 4FDC had a percentage content of 106.3% for Isoniazid that was above the BP 2008 specification of 95% to 105% and one sample of 2FDC had a percentage content of 105.6% for Isoniazid that was also above the BP. 2008 specification of 95% to 105%. All the 3FDC samples were compliant to the BP 2008 specification for percentage content of 95% to 105%.
Conclusion: The results from this study have established that substandard fixed dose combinations anti-TB drugs are present in Lusaka District. These results confirm the urgent need to have a national quality control laboratory that is supported by satellite mini laboratories at the points of entry for drugs and also to strengthen post marketing surveillance of all Pharmaceutical products that are imported into the country or manufactured locally. This will ensure safety and efficacy of the drugs that are used in the country.