Opened Vial of Insulin Can Be Stored for Four Weeks in Warm
Now open: Certificate Course in Management of Covid-19 by Govt. Of Gujarat and PlexusMDKnow more...Now open: Certificate Course in Management of Covid-19 by Govt. Of Gujarat and PlexusMDKnow more...
Diabetes requires an extremely precise form of daily treatment, whereby patients inject themselves with several doses of insulin every day. Patients must therefore keep a supply of insulin which, according to pharmaceutical protocol, must respect the cold chain from production to injection.

However, in some regions of the world like sub-Saharan Africa, not every household has a refrigerator, which forces people living with diabetes to go to hospital on a daily basis.

Faced with this issue, the researchers of University of Geneva (UNIGE) in the Dagahaley refugee camp (northern Kenya) found that the temperature in a home fluctuates between 25 degrees C at night and 37 degrees C during the day. The researchers then meticulously reproduced these conditions in laboratory setting, where they tested insulin storage. As insulin vials can be used for four weeks after opening, they carried out the measurements over the same timeframe, first with vials kept at the temperatures found in Dagahaley, and then with 'control' vials that were refrigerated. The UNIGE team used high-performance liquid chromatography to analyze the insulin.

The research results show that all the insulin preparations stored at fluctuating temperatures, recorded a potency loss of no more than 1%, just like those kept in cold storage during the required four weeks.

Crucially, the UNIGE researchers also observed that insulin activity was completely maintained. To verify this, they tested the action of insulin proteins on cells, compared with that of insulin that had been intentionally deactivated. "Finally, with the help of other researchers, we studied insulin vials that came directly from the Dagahaley camp, and always reached the same conclusion: the insulin was perfectly usable," says UNIGE researchers.

Overall, the study showed that a vial of insulin could be stored for four weeks after opening at temperatures fluctuating between 25 and 37 degrees Celsius (77 and 98.6 degrees Fahrenheit). This corresponds to the time it usually takes a diabetic person to finish one vial of insulin.

The findings demonstrate that the stability of insulin stored under these conditions is the same as that of cold-stored insulin, with no impact on efficacy. This allows people with diabetes to manage their illness without having to visit a hospital multiple times daily.

Researchers hope that a consensus statement will be drawn up, focusing on the at-home use of insulin in high-temperature settings when there is no refrigeration available, and that it will be endorsed by the WHO.