Quality of antiretroviral, antimalarial and antituberculosis medicines in Zambia: Findings of routine post-marketing surveillance

Abstract

Background: There is growing concern in sub-Saharan Africa that poor-quality antimicrobial medicines may negate management of infectious diseases of public health importance should they fail to meet the set criteria of quality, safety and efficacy. Objectives: The objective was to ascertain the quality of antiretroviral, antimalarial and antituberculosis medicines supplied and available in the public health sector in Zambia. Design: A descriptive cross-sectional study was conducted involving the analysis of data from the continuous routine in-country post-marketing surveillance programme in Zambia that assessed the quality of antiretroviral, antimalarial and antituberculosis medicines supplied to public healthcare facilities between January 2018 and June 2023. Methods: Data were extracted from laboratory quality analysis results from samples collected as part of routine post-marketing surveillance by the Zambia Medicines Regulatory Authority between January 2018 and June 2023. The samples were collected from various levels of the pharmaceutical supply chain across Zambia. Samples were analysed according to their respective pharmacopoeia standards at the Medicines Control Authority of Zimbabwe Quality Control Laboratory, a World Health Organization prequalified laboratory. Data were extracted using a structured Excel database and analysed using Microsoft Excel, and GraphPad Prism Software was used for visualizations. Results: Of the 198 samples, 86 (43.43%) were antiretrovirals, 54 (27.27%) antimalarials and 58 (29.29%) antituberculosis medicines. Of these 198 samples, 171 (86.36%) originated from Asia, 19 (9.60%) Africa and 8 (4.04%) Europe. All sampled medicines met their respective quality specifications with respect to tests, which included appearance, identification, assay, uniformity of mass, weight variation, disintegration, dissolution, pH and specific gravity, giving a compliance rate of 100%. Conclusion: Antiretrovirals, antimalarials and antituberculosis medicines obtained from public healthcare facilities in Zambia through routine post-marketing surveillance met their quality standards. This might positively impact treatment outcomes for HIV/AIDS, malaria and tuberculosis. There is a need for large-scale continuous monitoring of the quality of medicines in order to ensure quality is maintained and substandard products removed from the pharmaceutical supply chain.