22 Nov Drugs in Space: problems and countermeasure approaches for drugs exposed to the space environment
During a long-duration spaceflight it is pivotal the maintenance of crew health and performance, resulting in so essential the possibility to provide an effective medical treatment. Space medication has problems related to efficacy. Along with altered physiology associated with spaceflight, including effects on immune function and metabolism, one of the possible causes could be the instability of pharmaceutical products in the presence of spaceflight environmental conditions. Unique environmental conditions related to spaceflight includes microgravity, excessive vibration, hard vacuum, humidity variation, temperature differences and excessive radiation, all factors that may cause instability of medicines, resulting in reduced potency and efficacy. Usually, the shelf life of a given pharmaceuticals drugs is determined by drug manufacturers and expressed as an expiration date, after which time the manufacturer cannot guarantee the stability or potency of the medication. Shelf life of a drug may vary given the intrinsic differences in formulation or inclusion of variable excipients, packaging, or other factors.
Nowadays, medicines from the International Space Station are replaced before their expiration, however, for longer duration missions to Mars or Moon, there will not be chance of replacement. Hence, it is pivotal that medicines maintain the right efficacy and the shelf life throughout the space mission. It has been suggested that medications might degrade more quickly in space, but there is insufficient evidence to characterize stability for long-duration spaceflight, also because stability of drugs stored in spaceflight environmental conditions cannot be evaluate by drug stability guidelines based on terrestrial environmental factors. Various promising approaches are nowadays in studying to be used for assurance of space medicines stability. One of the approaches is the use of ground-based space simulation analogues and statistical treatment to data to calculate failure rate of drugs and probabilistic risk assessment. Another approach is to innovate storage and packaging technology using radiation harden polymer or using cryogenic temperatures.
References
- Mehta, P., & Bhayani, D. (2017). Impact of space environment on stability of medicines: challenges and prospects. Journal of pharmaceutical and biomedical analysis, 136, 111-119
- Blue, R. S., Bayuse, T. M., Daniels, V. R., Wotring, V. E., Suresh, R., Mulcahy, R. A., & Antonsen, E. L. (2019). Supplying a pharmacy for NASA exploration spaceflight: challenges and current understanding. npj Microgravity, 5(1), 1- 12