A recent Cochrane review reported that insulin maintains its efficacy even when stored at room temperature for long periods of time. This finding is particularly significant for diabetic patients who live in areas with limited medical care or without stable refrigeration equipment.
Insulin retains its effectiveness even when stored at room temperature for several months. The discovery offers significant hope for diabetic patients in areas with limited medical care or without stable refrigeration equipment. The impact is particularly profound for millions of people in low- and middle-income countries, especially in rural areas, and for those affected by conflict or natural disasters.
Human insulin is a hormone produced by the body that helps convert food into energy and control blood sugar levels. People with diabetes cannot make enough insulin, and people with type 1 diabetes must inject insulin several times a day, usually before each meal. Insulin is an essential medication for people with diabetes, and current guidelines state that it must be refrigerated before use to maintain its effectiveness.
However, the harsh reality for millions of people with diabetes living in low- and middle-income countries is that electricity and refrigeration are luxuries. Vulnerable people in conflict-torn areas, disaster-prone areas and areas affected by the climate crisis, including areas with extreme heat, also need solutions that do not rely on electricity-powered refrigerators.
A new Cochrane review summarizes the results of different studies that investigated what happens to insulin when it is stored outside the refrigerator, including previously unpublished data from the manufacturer.
The review found that unopened vials and kits of certain types of human insulin can be stored at 25°C for up to 6 months and at 37°C for up to 2 months without any clinically relevant loss of insulin activity. Data from one study showed that a specific type of insulin showed no decrease in insulin activity when stored at fluctuating ambient temperatures of 25°C to 37°C for up to three months. This fluctuation is similar to the diurnal temperature cycle in tropical countries.
A research team led by Bernd Richter from the Institute of General Practice, Faculty of Medicine, Heinrich-Heine University in Düsseldorf, Germany, conducted a comprehensive study to investigate the stability of insulin under various storage conditions.
The review analyzed a total of 17 studies, including laboratory investigations of insulin bottles, insulin cartridges/pens and prefilled syringes, and showed that insulin was consistently effective over a temperature range of 4°C to 37°C, with no clinically relevant loss of insulin activity.
Bernd emphasized the importance of this study, especially for people with type 1 diabetes, "Insulin is their lifeline because their lives depend on it. People with type 2 diabetes face various challenges, and people with type 1 diabetes need insulin to stay alive. This highlights the importance of diabetes in critical life circumstances." Patients are in desperate need of clear guidance, and many lack it. Our research opens up new possibilities for patients living in difficult environments with limited refrigeration. By understanding the thermal stability of insulin and exploring innovative storage solutions, we can have a significant impact on the lives of those who rely on insulin for their health."
These findings could help communities that face challenges in ensuring sustained cold storage of insulin. They provide confidence that alternatives to powered refrigerated insulin are possible without compromising the stability of this essential drug. Research shows that if reliable refrigeration is not possible, simple cooling devices, such as clay pots used for insulin storage, can be used to lower room temperature.
The researchers also noted uncertainties that need to be addressed in future research. There is still a need to better understand the effectiveness of insulin when stored under different conditions. Additionally, further research is needed on mixing insulin, the effects of exercise (e.g. when using an insulin pump), contamination in open vials and boxes, and research on cold environmental conditions.
Reference "Thermal Stability and Storage of Human Insulin" by Bernd Richter, Brenda Bongaerts and Maria-IntiMetzendorf, November 6, 2023, Cochrane Database of Systematic Reviews.
DOI:10.1002/14651858.CD015385.pub2
Compiled source: ScitechDaily