A study to determine the quality of fixed dose combination(FDC)anti tuberculosis drugs in Lusaka District

Apart from struggling with the burden of communicable diseases, developing countries such as Zambia are also faced with the challenge of the availability of counterfeit and substandard medicines on their markets which are an insidious 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.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. Samples of five 4FDC, five 3FDC and seven 2FDC anti TB drugs from Lusaka district were analyzed for presence of active ingredients and percentage content. The drug samples that were analyzed had a shelf life of at least one year. A sample comprised two blister packs each containing 28 tablets. The tablets were number coded before taking them to Tejay Pharmaceuticals Laboratory for analysis.
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 on the label claim. However, 1 in 5 of the 4FDC samples were none compliant to the BP 2008 specification for percentage content. One sample had a percentage content of 106.3% of Isoniazid that was above the BP 2008 specification of 95% to 105%. All the 3FDC samples were compliant to the BP 2008 specification of 95% to 105%, but 1in 7 of the 2FDC samples had a percentage content of 105.6% for Isoniazid that was marginally above the BP. 2008 specification of 95% to 105%. This study has shown that substandard anti Tuberculosis drugs are present in Lusaka district. The results have shown that 1/5 of the samples for 4FDC were none compliant for Isoniazid to the BP 2008 specifications for percentage content and 1 in 7 of the samples for 2FDC were none compliant to the BP 2008 specifications for percentage content for Isoniazid.