Stability of Dihydroartemisinin-Piperaquine Tablet Halves during Prolonged Storage under Tropical Conditions

Dihydroartemisinin-piperaquine (DP) is recommended for the treatment of uncomplicated malaria, used in efforts to contain artemisinin resistance, and increasingly considered for mass drug administration. Due to the narrow therapeutic dose range and available tablet strengths, the manufacturers and World Health Organization recommended regimens involve breaking tablets into halves to accurately dose children according to body weight. Use of tablet fractions in programmatic settings under tropical conditions requires a highly stable product, however, the stability of DP tablet fractions is unknown. We aged full and half Eurartesim® DP tablets in a stability chamber at 30°C and 70% humidity level. The active pharmaceutical ingredients dihydroartemisinin and piperaquine remained at ≥95% over the 3 months period of ageing in light and darkness. These findings are reassuring for DP, but highlight the need to assess drug stability under real-life settings during the drug development process, particularly for key drugs of global disease control programmes.