The long-term stability of solid-state oral pharmaceuticals exposed to simulated intravehicular space radiation

Pharmaceutical products brought for space missions must remain effective and safe throughout the mission. Previous NASA experiments suggest that radiation exposure could threaten drug stability during long-duration space missions. The Exploration Medical Capability (ExMC) Element has evaluated this possibility by exposing four medications to simulated Galactic Cosmic Radiation (GCRSim) at the NASA Space Radiation Laboratory followed by a three-year storage period. The solid oral drug products Acetaminophen, Amoxicillin, Ibuprofen, and Promethazine were used. Identical lots of each medication were assigned to four experimental groups: the non-irradiated Johnson Space Center control group, the non-irradiated traveling control group, the irradiation group I (GRSim, 0.5 Gy), and the irradiation group II (GCRSim, 1.0 Gy). Drug products were assessed for active pharmaceutical ingredient, degradation impurities, and dissolution 2, 18, and 34 months after irradiation. All samples show comparable degradation, revealing that GCR exposure does not facilitate the degradation of the drugs.