From the Guidelines
Meal time insulins like insulin aspart and insulin lispro do not require refrigeration for daily use once opened, and can be kept at room temperature for up to 28 days after first use. These rapid-acting insulins can be stored at ambient temperatures (15 to 30 °C or 59 to 86 °F) away from direct sunlight exposure until the expiration date designated by the manufacturer 1. However, unopened insulin pens or vials should be stored in the refrigerator (2 to 8 °C or 36 to 46 °F) until their expiration date to maintain potency 1. It is essential to check the temperature of the refrigerator where insulin is stored, as household refrigerators are commonly outside the recommended range 1. When carrying insulin, it is crucial to protect it from extreme temperatures and direct sunlight 1. After the 28-day room temperature period, any remaining insulin should be discarded even if not expired, as the effectiveness gradually decreases over time at room temperature.
Some key points to consider when storing meal time insulin include:
- Checking the expiration date and ensuring the insulin is not cloudy before use 1
- Avoiding removal of insulin from a prefilled disposable insulin pen using a syringe to fill another device, unless absolutely necessary 1
- Storing insulin at the correct temperature to maintain its potency 1
- Protecting insulin from direct sunlight and extreme temperatures 1
It is also important to note that the storage guidelines for insulin products may vary by product and regional practices, and healthcare providers should personalize instructions per the relevant manufacturer’s guidelines 1.
From the Research
Meal Time Insulin Storage
- Meal time insulin, such as insulin aspart or insulin lispro, has specific storage requirements to maintain its potency and effectiveness.
- According to the studies, unopened vials of human insulin can be stored at room temperature (up to 25°C) for up to six months or at up to 37°C for up to two months without significant loss of insulin activity 2.
- Once opened, insulin can be stored at room temperature for four to six weeks, depending on the manufacturer's recommendations 2.
- Some studies have shown that insulin can be stored at oscillating temperatures between 25°C and 37°C for up to three months without loss of insulin activity 2, 3.
- However, it is essential to note that storage conditions can affect insulin's blood glucose-lowering effect, and temperatures outside the recommended range can lead to insulin degradation 4.
Refrigeration Requirements
- Refrigeration is recommended for storing unopened insulin vials, but once opened, insulin can be stored at room temperature 2.
- Domestic refrigerators may pose a risk for insulin quality, as temperatures can deviate from the recommended range 4.
- Carrying insulin at room temperature, especially in hot weather conditions, can also affect its potency, but devices like ViViCap-1 can help maintain the internal temperature of insulin pens 5.
Stability of Insulin at High Temperatures
- Studies have shown that basal insulin in a pen can retain its potency and biological activity even when stored at 37°C for 21 days 6.
- Insulin heat stability has been assessed under tropical temperature conditions, and results indicate that insulin can be stored at oscillating ambient temperatures for the usual four-week period of use 3.
- However, it is crucial to follow the manufacturer's recommendations and take precautions to maintain the insulin's potency and effectiveness.