Return of the Ritonavir: A Study on the Stability of Pharmaceuticals Processed in Orbit and Returned to Earth

Despite notable progress in realizing the benefits of microgravity, the physical stability of therapeutics processed in space has not been sufficiently investigated. Environmental factors including vibration, acceleration, radiation, and temperature, if not addressed could impact the feasibility of in-space drug processing. The presented work demonstrates the successful recovery of the metastable Form III of ritonavir generated in orbit. The test samples and passive controls containing each of the anhydrous forms of ritonavir; Form I, Form II, and Form III, and amorphous - exhibit excellent stability. By providing a robust experimental dataset centered on survivability, we pave the way for the future of in-space processing of medicines that enable the development of novel drug products on earth and benefit long-duration human exploration initiatives.