A pilot-scale study was led by Virginia Wotring of the Center for Space Medicine and Department of Pharmacology at Baylor College of Medicine in the U.S., which stated that medicines behave similarly in space and on Earth. This was done to derive evidence regarding how medicines might react to factors that are unique to spaceflight, such as microgravity and constant exposure to elevated radiation levels.
Scientists had tested some drugs that were brought back from the International Space Station, ISS. They did so because they wanted to figure out whether medicines exposed to microgravity or higher radiation levels degrade earlier. The drugs tested include sleeping pills, alertness medications, drugs used to treat diarrhea that are regularly supplied to the ISS in order to replace the expired medicines.
The study appears in The AAPS Journal, an official journal of the American Association of Pharmaceutical Scientists. It was published by Springer.
The medications were taken to the ISS by Russia’s Progress spacecraft and after the drugs were stored in the space research complex for about 550 days, it was returned back to Earth via Dragon (SpaceX) capsule. For the analysis, drug samples were sent to California using a boat before it was flown to JSC in Houston, Texas. The total time of travel from capsule splashdown to the final destination was more or less 58 hours.
Medicines on Earth tend to expire after a specific time and they degrade earlier when they are exposed to heat or light, humid surroundings and oxygen.
The temperature and humidity conditions maintained in the ISS are similar to that of Earth. While testing the drugs, the scientists measured the amount of active ingredients and products that lead to degradation of the drugs.
About nine drugs were tested for active pharmaceutical ingredient (API) and degradant amounts. The analysis results were then compared to 2012 United States Pharmacopeia (USP) requirements.
USP guidelines offer apparent requirements of the quantity of active ingredients and limits of degradation products present in a drug. This information helps scientists decide if the drug works effectively after they are stocked in the ISS.
Following the lengthy storage under extreme conditions in space, the tests show that no unusual degradation products were seen in any of the medicines.
The study states that one particular medicine met USP requirements despite expiring five months ago. Out of the nine drugs tested, four drugs were still safe to use up to eight months after officially expiring. Three drugs fulfilled the USP guidelines when they were tested three months prior to their expiry date. A dietary supplement and a sleeping failed to meet USP requirements 11 months after it had expired.
The findings are based on a handful of medicines and scientists believe that the tests can help plan long-term space exploration missions like missions to Mars.
The study further states that more convincing evidence is needed to derive conclusive conclusions. The next step is to carry out more thorough stability studies maintaining appropriate controls and multiple time points.