A Reusable Cap for Disposable Insulin Pens Protects Insulin against Temperature-Induced Degradation

Insulin has to be kept at 4-8° C (∼ 39°F to 47°F) until use and once opened, is supposed to be stable for 28 to 30 days at room temperature. Exposure to extreme cold or heat leads to insulin degradation in a very short time with loss of glucose-lowering efficacy. ViVi-Cap (TempraMed Inc.) is a reusable storage device, which is available for all existing disposable pen devices in the U.S. and EU. It works without external power supply requirements based on an ultra-high vacuum insulation and an additional heat consumption by a calorimetry-based phase-change technology.

Five disposable insulin pens (FlexPen, Insulin aspart) were kept for one week under extreme temperature conditions for 5 days (each day: 8 h at 50 °C and 16 h at 22 °C) either without protection, in a frio device (freshly prepared each day) and in the ViViCap. Samples were taken every day and insulin degradation was determined in accordance with U.S. pharmacopoia by appropriate HPLC methods for insulin aspart, and high and low molecular weight degradation molecules. Each experiment was performed in triplicate.

Insulin aspart without protection was shown to have more than 2% impurities already after one day (Frio: 2 days, ViViCap: >5 days). High molecular weight products appeared in measurable quantities after two days without protection (Frio: 3 days, ViViCap > 5 days, p<0.01 against the other 2 storage conditions).

ViVi-Cap was superior to the other tested conditions with respect to stabilizing insulin aspart during storage under extreme temperature conditions. The device provides an easy to use solution for maintaining insulin efficacy under daily life conditions.