Drug potency – what happens in space?
Study finds some pharmaceuticals flown on space missions may have their potency compromised
Some of the Pharmaceuticals intended for the treatment of minor illnesses of astronauts in space may require special packaging and reformulation to remain stable for long periods in the space environment. That’s according to Dr. Putcha and her colleagues from NASA, Johnson Space Centre. Their findings, published online in AAPS Journal suggest that some of the pharmaceuticals stored on space flights may have shorter shelf-life than they do on Earth.
Pharmaceuticals used on space flights are packed and dispensed in special flight-certified containers and stored in compact flight kits. They may be exposed to the unique environ-mental factors of space missions such as radiation and excessive vibration in addition to variations in temperature and humidity.
Scientists at the Johnson Space Centre investigated whether pharmaceuticals undergo degradation in space and, if so, which environmental variables in space may affect the stability of the medications in space. They compared physical and chemical changes in 35 formulations contained in identical pharmaceutical kits stowed on the International Space Station (ISS) and on Earth.
After stowage for 28 months in space, they found that a higher percentage of the medications from each flight kit had a lower active pharmaceutical content than the controls on the ground. They also saw no variation in the temperature or humidity levels between Earth and in space.
Putcha and her colleagues suggest that exposure to the chronic low dose of ionizing radi-ation as well as repackaging of solid medications may be contributing factors for phar-maceutical stability in space.
The authors conclude: “It is important to characterize space-specific degradation products and toxicity limits using ground-based analogue environments of space that include proton and heavy ion radiation, vibration and multiple gravity conditions. This information can facilitate research for the development of space-hardy pharmaceuticals and packaging technologies.” Reference
1. Du B, Putcha L et al (2011). Evaluation of physical and chemical changes in pharmaceuticals flown on space missions. The AAPS Journal. DOI 10.1208/s12248-011-9270-0
Abstract
Efficacy and safety of medications used for the treatment of astronauts in space may be compromised by altered stability in space. We compared physical and chemical changes with time in 35 formulations contained in identical pharmaceutical kits stowed on the International Space Station (ISS) and on Earth. Active pharmaceutical content (API) was determined by ultra- and high-performance liquid chromatography after returning to Earth. After stowage for 28 months in space, six medications aboard the ISS and two of matching ground controls exhibited changes in physical variables; nine medications from the ISS and 17 from the ground met the United States Pharmacopeia (USP) acceptance criteria for API content after 28 months of storage. A higher percentage of medications from each flight kit had lower API content than the respective ground controls. The number of medications failing API requirement increased as a function of time in space, independent of expiration date. The rate of degradation was faster in space than on the ground for many of the medications, and most solid dosage forms met USP standard for dissolution after storage in space. Cumulative radiation dose was higher and increased with time in space, whereas temperature and humidity remained similar to those on the ground. Exposure to the chronic low dose of ionizing radiation aboard the spacecraft as well as repackaging of solid dosage forms in flight-specific dispensers may adversely affect stability of pharmaceuticals. Characterization of degradation profiles of unstable formulations and identification of chemical attributes of stability in space analog environments on Earth will facilitate development of space-hardy medications.
