A team made up of employees from the University of Geneva and from Doctors Without Borders was able to show that an opened insulin cartridge can be stored for four weeks at 37 ° C without impairing its effectiveness.
A person with diabetes must adhere to an individualized treatment plan and inject insulin on a daily basis. The dose depends on diet and physical activity. Patients have a supply of insulin ampoules, which must be stored refrigerated from manufacture to use in accordance with pharmaceutical guidelines. In certain regions of the world, such as sub-Saharan Africa, not all people have a refrigerator. Diabetics are therefore forced to go to a clinic every day for the injections. Doctors Without Borders / Médecins Sans Frontières (MSF) has therefore teamed up with the University of Geneva to test the storage of insulin under real conditions. Specifically, it was temperatures between 25 ° C and 37 ° C over a period of four weeks, which corresponds to the usual usage time of an ampoule. The results, which were published in the online journal PLOS ONE, have shown that the effectiveness remains the same as compared to insulin stored in a refrigerator. This enables diabetics to deal with their illness in a self-determined manner; constant visits to clinics are no longer necessary.
In type 1 diabetes, the blood sugar level is increased. Complications as severe as coma, blindness, limb loss, or death can occur. The disease can now be treated well, but daily insulin therapy is required, with the help of which the glucose in the blood is transported into the cells. “According to the current pharmaceutical guidelines, the insulin ampoules must be permanently stored between 2 ° and 8 ° C, so the cold chain must not be interrupted,” says Philippa Boulle, an expert on chronic diseases at Doctors Without Borders. “That is of course difficult in certain places, especially in refugee camps where the families don’t have a refrigerator.” Certain diabetics therefore have to travel long distances every day for the injections. For some it even means that they can no longer work because of it. “We turned to the team of Leonardo Scapozza, Professor of Pharmaceutical Sciences at the University of Geneva, to thoroughly analyze the storage conditions of insulin without compromising its effectiveness,” continues Boulle.
A study under real conditions
The experts have found that the temperatures in accommodation in the Dagahaley refugee camp, in northern Kenya, fluctuate between 25 ° C at night and 37 ° C during the day. They reproduced exactly these conditions in the laboratory and tested the storage of insulin there. “Opened ampoules are usually used up in four weeks. We therefore used the same duration for our investigations – once with ampoules that were stored at the ambient temperature of sub-Saharan Africa and once with cooled ampoules, ”explains Leonardo Scapozza. The university team analyzed the insulin protein using the high-performance liquid chromatography method. “There is a risk that the insulin protein will form a type of flake when exposed to heat, which is no longer liquid and can therefore no longer be injected”,
No difference between the storage conditions
The results of the investigations show that the insulin preparations that were exposed to a fluctuating room temperature show a loss of no more than 1% – just like the preparations that were stored in a cool place during the four weeks. «The law on pharmaceutical preparations allows a loss of up to 5%. So we’re way below that, ”says a delighted Leonardo Scapozza.
Another important point: The researchers at the University of Geneva also found that the insulin activity remained completely intact. To check this, they tested insulin proteins on cells and compared their reaction with insulin that was voluntarily deactivated. “Finally, with the help of Professor Michelangelo Foti’s group, we examined insulin ampoules straight from the Dagahaley warehouse with the same result: the insulin was perfectly usable,” says Scapozza.
Results that can change the everyday lives of thousands of people
A scientific study thus proves for the first time that insulin cartridges can be used for four weeks even in hot weather without having to be stored in the refrigerator. “These results can serve as a basis for changing the way we view diabetes in resource-poor environments,” explains Boulle. In this way, people with diabetes would no longer have to come to the hospital every day for their insulin injections and could lead a normal life again. “Of course, this also requires educational and support measures so that those affected are able to measure their blood sugar level and inject the right amount of insulin.