Re-evaluating pharmaceutical stability in space: A biomedical and regulatory science framework for long-duration...

Pharmaceutical stability is a critical determinant of crew health and mission success in long-duration spaceflight. Current regulatory frameworks governing drug stability are primarily based on terrestrial testing paradigms, including International Council for Harmonisation (ICH) guidelines, which assume controlled environmental conditions. However, spaceflight introduces unique stressors such as microgravity, ionizing radiation, exposure to the vacuum of space,and operational constraints that are not accounted for in existing models. This study systematically evaluates the limitations of current regulatory systems through a structured review of experimental evidence, space agency reports, and regulatory documents. Findings indicate that pharmaceutical degradation in space deviates significantly from Earth-based predictions due to multi-factorial interactions and highly formulation-dependent vulnerabilities. Additionally, fragmentation across regulatory and operational bodies results in inconsistent handling of pharmaceuticals across missions. The efficacy of physiological countermeasures against spaceflight-induced adaptations heavily relies on the integrity of these medications. Based on these findings, this study proposes a biomedical and health-centric regulatory science framework incorporating environment-specific testing, standardized packaging, dynamic shelf-life management, and international data integration. The proposed framework aims to enhance predictive reliability, mitigate clinical risks, and safeguard astronaut health and physiological resilience in future deep space missions.