A Comprehensive Assessment of Quality of Antimalarial Medicines in Mainland Tanzania: Insights from Five Years of Postmarket Surveillance.

Sustainable access to high-quality antimalarial medicines is pivotal to achieving universal and effective malaria control. Poor-quality antimalarial medicines are prevalent in sub-Saharan Africa, impeding malaria control initiatives and claiming the lives of many children. Regular monitoring of the quality of antimalarial medicines is crucial to ensure the quality of service to the community. A cross-sectional study using a postmarket surveillance (PMS) approach was conducted from 2019 to 2023. Samples were collected from the port of entry, local manufacturers, and various distribution outlets in 15 regions of mainland Tanzania. The samples were subjected to tier 1 evaluation, comprising a product information review (PIR) and identification using the Global Pharma Health Fund-Minilab® techniques. Samples that failed the identification tests and 10% of the samples from distribution outlets that passed the tests were subjected to confirmatory testing (tier 2), which included assays, related substances, dissolution, and sterility per the pharmacopeial monographs. During five annual PMSs, 2,032 antimalarial samples were collected and subjected to quality tests. All samples complied with the standard specifications for identity, dissolution, related substances, sterility, physical evaluation, disintegration, and assay. A total of 292 (55.5%) tested samples failed the PIR evaluation, with incomplete package information in leaflets contributing to 64.7% of all deviations. Antimalarial medicines circulating in the mainland Tanzanian market meet expected quality standards. Continuous monitoring of the quality of antimalarial medicines is recommended.