Looking after your Insulin and Injecting Devices
- To ensure that your insulin remains effective, stable and undamaged you should discard your ‘in use’ insulin after 28days, whether in a vial or cartridge.
- Insulin that is not in use should be stored in the refrigerator. If refrigeration is not possible, it can be kept at room temperature [15-25 degrees C] for 28 days.
- The in use vial may be kept at room temperature [15-25 degrees C] for 28 days.
- In use cartridges should be kept at room temperature and SHOULD NOT be kept in the refrigerator.
- Insulin has a ‘use by’ date as well as an expiry date.
The advice about storing insulin may differ from one manufacturer to another and so we have obtained information from the various companies:
Wockhardt UK, formerly CP Pharmaceuticals Ltd – manufacturers of natural pork and beef insulins:
"Our recommendation is that a single vial may be used repeatedly over a 3 month period, as long as the vial is maintained at the correct storage temperature of 2 to 8 degrees C.
If the vial is stored outside the refrigerator [at room temperature] then this period of use should be reduced to 28 days. This also assumes that the vials are appropriately stored and are used under normal conditions [that is to avoid microbial contamination]. Insulin in cartridges is stable for up to 4 weeks once open if stored at 25 degrees C. We do not recommend that ‘in use’ cartridges are stored in the refrigerator."
Novo Nordisk Pharmaceuticals Ltd – manufacturers of synthetic insulins, ‘human’ and analogues
No information supplied
Eli Lilly – Manufacturers of synthetic insulins – ‘human’ and anaolgues.
"Our Humulin range has regulatory approval for in-use out of the fridge for 28 days. We have also performed our own in-house studies, however these were also completed after 28 days. Therefore, we do not have any data on in-use of Humulin vials after 28 days and thus, although we have no information to suggest that there is any problem with in-use vials stored in the fridge after 28 days, without data to support this we currently can only recommend in-use for 28 days."
Patients should always discard their ‘in use’ insulins after 28 days as a necessary precaution
Why is this important?
There are no insulins that mimic the human body’s production of insulin in response to food intake. Diabetes is not an easy condition to live with and people with diabetes are individuals with different hormonal and metabolic rates. Each person responds to insulin in different ways.
There are many variables that affect diabetic control, such as:
- Diet and exercise
- Fears of low blood sugars [hypoglycaemia]
- Emotions and stress
Diabetes will remain a difficult and complex condition until we are provided with better ‘tools’ with which to control it. Until then it is important that we rule out anything which could affect our diabetic control. This must include ruling out the possibility that our insulin has started to break down so that it is less potent. This results in it being absorbed and moved around the body differently, so affecting blood glucose levels.
It is also important to realise that if we have been using ‘old’ insulin that has gone off, with a change to a new fresh fully effective vial there is a greater chance of a severe hypo at the changeover time.