It is possible to store insulin at room temperature in warm regions?

Without refrigeration to store insulin, some diabetics in warm regions have to go to hospital every day to receive their injection. This is common in certain African refugee camps and new findings hint at a solution.

Evaluating the stability of insulin without refrigeration

In the absence of a refrigerator to store their insulin, diabetics living in certain hot regions have to go to the hospital every day to receive their injection. This is particularly the case in Africa in refugee camps. At the request of Doctors Without Borders (also known as MSF), researchers evaluated the stability of insulin when an opened vial is stored at room temperature.

Made in cooperation with our partners from esanum.fr

"They will be able to take back control of their lives. In rich countries the question doesn't even arise, it is quite normal for people with diabetes to inject their insulin. But in low-income countries, only half of the people who need insulin have access to it," says Philippa Boulle, advisor to Médecins Sans Frontières (MSF). This is due to the high price of insulin, the complex treatment protocols and the difficulties of storage.

In some hot regions of the world - particularly in sub-Saharan Africa - not all diabetics have access to a refrigerator. They have to go to the hospital every day, usually twice, to receive their insulin injection. This situation is even more difficult in refugee camps, where curfews are frequent, preventing patients from moving in the evening and therefore from receiving their injections.

For a few more degrees

Dagahaley is one of three refugee camps that make up the Dadaab complex in Kenya. Opened in 1991 to house people fleeing the civil war in Somalia, Dadaab has seen its numbers grow rapidly in 2011 due to famine in southern Somalia. For a long time considered the largest refugee camp in the world - with nearly 500,000 people in 2012 - Dadaab officially hosted 220,000 people in 2020. People have been living in this camp for 30 years, twice threatened with closure by the Kenyan government in response to terrorist attacks.

In Dagahaley, MSF has a 100-bed hospital. Alarmed at the increase in diabetes-related complications, MSF asked Swiss researchers to study the stability of insulin when exposed to temperatures such as those found in the camp. "The current pharmaceutical protocol requires that insulin vials be kept at 2° to 8°C until they are opened, carefully following the cold chain, after which human insulin - the most widely used in low-income countries - can be stored at up to 25°C for up to four weeks," said Boulle.

Four weeks is the length of time an open bottle can be used. The study in question therefore focused on testing the storage of insulin under real conditions, i.e. for this length of time and at temperatures between 25°C and 37°C. The results are conclusive: the efficacy and the quantity of insulin that can be used are not altered. 

A study under real conditions

Researchers replicated the conditions of a house in a refugee camp in northern Kenya (where temperatures range from 25°C at night to 37°C during the day) in the laboratory. "We carried out measurements for four weeks, once on insulin vials stored at room temperature from sub-Saharan Africa and once on "control" insulin vials stored in cold storage," explains Leonardo Scapozza, professor of pharmaceutical sciences at the University of Geneva. 

Using the method of high-performance liquid chromatography, the researchers analyzed the insulin protein. "The risk is that under the effect of heat the insulin protein precipitates," says the researcher. In such a case, it is obviously no longer possible to inject it. 

The results of the study show that all insulin preparations stored at room temperature had recorded a loss not exceeding 1%, as those stored in cold storage during the four weeks required by law. This is well below the 5% tolerated by the legislation on pharmaceutical preparations. 

The researchers also found that insulin activity remained completely intact. They tested insulin proteins on cells and compared their reaction with voluntarily deactivated insulin. "We studied insulin vials coming directly from the Dagahaley camp and obtained the same finding, insulin was perfectly usable" says Leonardo Scapozza.

Will the pharmaceutical companies follow?

Such a change in diabetes management would enable people with diabetes in the affected areas to avoid going to the hospital every day. In the camps, this strong constraint further weakens refugees with precarious living conditions, for example by preventing them from working. MSF would therefore like pharmaceutical companies to adapt their recommendations and for the WHO to approve a consensus statement on the domestic use of insulin at warm temperatures in the absence of refrigeration.

Insulin could then be transported and stored in locally manufactured refrigerated containers in the homes of diabetes patients. This change "will have to be accompanied by education, support and follow-up programs, so that diabetics are able to measure their blood sugar levels and inject the right amount of insulin," recommends Philippa Boulle. 

References:
MSF - Dadaab Refugees in Kenya: Locked up and forgotten, they call for dignity (In French)
UNIGE (University of Geneva ) - Press release: Storing insulin at high temperatures is possible! (Original in French: Communiqué de presse : Stocker son insuline à des températures élevées, c’est possible !)