The discovery of the two unsymmetrically coupled dimeric naphthylisoquinoline alkaloids, the mbandakamines B3 and B4, showing a high steric hindrance at the central biaryl axis and displaying pronounced antiplasmodial activities, is described.

In the context of post-marketing surveillance supporting public-health authorities to take evidence-based decisions to fight the spread of poor-quality medicines, the quality of antimalarial artemether-lumefantrine (AL) medicines was assessed in the Democratic Republic of the Congo (DRC). A total of 150 samples of AL-containing products was collected from private pharmaceutical outlets in 8 main cities: Goma, Kikwit, Kinshasa, Kisangani, Lubumbashi, Matadi, Mbandaka, and Mbuji-Mayi. All drug samples were successively analyzed by visual inspection, thin-layer chromatography (TLC), and high-performance liquid chromatography (HPLC) following The International Pharmacopoeia. Of the 150 collected drug samples, 3 (2%) failed the visual inspection as they had shelf lives different from those of other samples with the same brand name. Four samples (2.7%) did not pass the TLC test as they contained only 1 or even none of the 2 declared active pharmaceutical ingredients (APIs). HPLC assays showed that 46 (30.7%) samples had artemether contents below 90% and 17 (11.3%) above 110% of the content claimed on the label. For lumefantrine, 32 (21.7%) samples had contents below 90%, and 8 (5.3%) had contents above 110%. This survey in DRC gives evidence that poor-quality antimalarial medicines are widely present. Based on 3 detection techniques, the study shows the necessity to equip developing countries with modern techniques such as HPLC, which, if combined with affordable techniques like TLC, could provide a pertinent analytical strategy to combat drug counterfeiting and poor manufacturing.

A simple and robust CZE method was developed for the separation and quantification of the antimalarial compound amodiaquine as well as three of its synthetic impurities at a concentration equal to or lower than 0.5%. For capillary electrophoresis, a fused-silica capillary, a background electrolyte of 100 mM sodium phosphate buffer at a pH value of 6.2, a voltage of +20 kV, and a detection wavelength of 220 nm were used, allowing the determination of the analytes within 20 min. The method was validated according to the guideline Q2(R1) of the International Council for Harmonization with respect to linearity, precision, accuracy, limit of detection and limit of quantification, and was successfully applied to evaluate the quality of drug samples collected in the Democratic Republic of the Congo. Quantitative analysis results obtained by the CZE method were compared to those obtained with the contemporary HPLC method described in The International Pharmacopoeia.