Stability of Pharmacotherapeutic (Stability-Pharmacotherapeutic) studies the effects of radiation in space on complex organic molecules, such as vitamins and commonly used medicines. This helps researchers develop more stable and reliable pharmaceutical countermeasures suitable for future long-duration missions beyond low Earth orbit.Principal Investigator(s)
Johnson Space Center, Human Research Program, Houston, TX, United States
National Aeronautics and Space Administration (NASA)Sponsoring Organization
Human Exploration and Operations Mission Directorate (HEOMD)ISS Expedition Duration:
April 2006 - April 2009
13,14,15,16,17,18Previous ISS Missions
Stability-Pharmacotherapeutic is a unique investigation that was begun during ISS Expedition 13.
Data gathered from past Space Shuttle missions suggest that some of the medications packed in the shuttle medical pack degrade even after relatively brief periods (less than 20 days) of space flight. The observed degradation included both physical and chemical characteristics for the medication formulations. The observed degradation suggested a deviation from the FDA stipulated shelf-life for the formulations, which could result in a loss of potency. Physical and chemical instability of medications could render treatments ineffective for assurance of optimal crew health during long-duration space exploration missions. An evaluation of subjective data on medications used by crewmembers during the first 89 Space Shuttle missions indicated that 8% of all treatments administeredwere reported as ineffective.
Pharmaceutical instability may modify effectiveness and safety, and is one possible cause of the ineffectiveness of treatments. The stability of medications used by the crew must be adequate to facilitate safe exploration of space in the future. The Stability of Pharmacotherapeutic (Stability-Pharmacotherapeutic) investigation evaluates mission critical medications to understand issues relating loss of potency for medicines in space. Results from this investigation offers an assessment of the stability and chemical integrity of medications in adverse environments encountered during space missions. This information will also assist in identifying susceptible medications that may require alternate methods of preparation, dispensing and storage to improve stability and minimize loss of potency during space missions. Estimates of shelf life and potency from Stability data can be used for the selection, modification and development of drug dosage forms and storage techniques for the International Space Station (ISS), and future long-duration missions. The data will also enhance our understanding of the conditions that contribute to pharmaceutical instability and help define mitigation strategies that assure adequate drug stability for human exploration of space.
Four identical Stability kits were delivered to the ISS in July 2006 during the STS-121/ULF1.1 mission. The first kit was returned to Earth during the STS-121/ULF1.1 mission. The second kit was returned after 11 months of exposure during the STS-117/13A mission in June 2007. The third kit was returned after 1 year and 7 months of exposure during the STS-122/1E mission in February 2008. The fourth kit was returned on STS-126/ULF2 in November 2008.
Results of this investigation provides important information on the susceptibility of select pharmaceuticals to adverse environmental factors encountered during space missions.Earth Applications
The results of this investigation helps to understand the effects of adverse environments on medicines, this information will assist Earth based explorers making healthy choices for long-term exploration of remote and adverse habitats like the Antarctic, arctic and the world oceans.
Each kit consists of 35 pharmaceutical preparations, a passive dosimeter and a temperature monitor. Each kit will be stored for different periods of time to gather time course data on radiation and temperature conditions on board. All sample kits flew to ISS on STS-121/ULF1.1 in July 2006. Kit 1 was returned on STS-121/ULF1.1 in July 2006; Kit 2 was returned on STS-117/13A in June 2007; Kit 3 will return on STS-122/1E in February 2008; Kit four will be returned on a future flight. Storage requirements for all three kits are that they must be stowed together on ISS, the location in relation to on-board radiation monitors must be identified, and they should not be stowed next to a heat source.Operational Protocols
This is a passive investigation that will require minimal crew time while on orbit. The crew will transfer the sample kits from Shuttle to ISS; then back to Shuttle at the appropriate time intervals. Following return to Earth the samples will undergo a battery of physical and chemical evaluations to determine shelf-life and degradation profiles of medications.
The Stability-Pharmacotherapeutic investigation studied the effects of radiation in space on medicine at varying time intervals. Thirty-five medications were examined in this experiment. The study found that six medications stowed for the longest duration of 28 months on-board the ISS showed physical alterations as compared with only two medications stowed on the ground for the same length of time. Also, nine medications stowed for 28 months on-board the ISS met United States Pharmacopeia (USP) potency standards versus 17 medications stowed for the same length of time on the ground. Several formulations had lower potency, in general, after storage in space, and a larger amount of formulations failed USP potency requirements after each storage period interval in space than on Earth. The potency degradation rate was found to be faster for several medications in space than on Earth; this was the particular case for light-sensitive medications and may be the result of exposure to higher amounts of radiation aboard the spacecraft than on the ground. Repackaging of solid dosage forms from the original commercial containers into the custom-manufactured containers used to store medications in the space medical kits may also have had an influence on the stability of the medications. These findings will contribute to the future development of space resilient medications and medicine packaging technology (Du et al. 2011).
Du B, Daniels VR, Vaksman Z, Boyd JL, Crady C, Putcha L. Evaluation of Physical and Chemical Changes in Pharmaceuticals Flown on Space Missions. American Association of Phamaceutical Scientists Journal. 2011; 13(2): 299. DOI: 10.1208/s12248-011-9270-0.