The Effect of high temperature on the stability of basal insulin in a pen: a randomized controlled, crossover, equivalence trial

Abstract

IntroductionInsulin is an essential medicine in the management of diabetes. When stored at high temperatures(HTs), its efficacy could rapidly decline. Therefore, appropriate storage of in-use insulin is necessary to achieve its maximum therapeutic effects. However, the ambient temperature in tropical countries is normally relatively high. This study aimed to compare the efficacies of basal insulin in a pen previously kept at 37°C for 21 days and basal insulin in a refrigerated pen (2°C–8°C). Continuous glucose monitoring (CGM) was used to evaluate daily mean glucose levels (MGLs).Research design and methodsThis randomized controlled, crossover, equivalence trial recruited adults with type 2 diabetes mellitus and glycated hemoglobin levels <8% who had used insulin glargine for >3 months. Subjects were randomized for sequential use of refrigerated basal insulin followed by basal insulin kept at HT, with a 2-week washout between phases. The HT insulin pens were stored in a 37°C incubator for 21 days before use, while the refrigerated insulin pens were stored at 2°C–8°C. Study patients received 7-day CGM. The primary outcome was the difference in the groups’ MGLs. The secondary outcome parameters were glucose variability represented by the standard deviation (SD), mean amplitude of glycemic excursion (MAGE), and percentage of time in range (TIR). The remaining quantity of insulin was evaluated by ultrahigh-performance liquid chromatography (UHPLC) assay.ResultsForty patients completed the study. The MGLwas 158.7±30.5 mg/dL and 157.0±40.9 mg/dL in the HT and refrigerated insulin pen groups, respectively (p=0.72). The groups had no significant differences in MAGE7day, SD, percentage of TIR, carryover period, or treatment effects (all p>0.05). There was also no significant difference in the remaining quantity of insulin evaluated by UHPLC (p=0.97).ConclusionsHT basal insulin pens retain their potency and have biological activity comparable to that of refrigerated pens.Trial registration numberTCTR20210611002.

Cross-sectional Study of Insulin Pen Storage Knowledge and Related Factors in Vietnamese People with Diabetes

“…Improper insulin storage reduces its pharmacological effectiveness and potency, thereby reducing the quality of treatment. 10 If not stored correctly, it will easily cause bacterial infections. It is impossible to treat T2DM at that time effectively, and infected insulin can cause other serious health effects.…”

“…Insulin is unstable and sensitive to extreme temperatures and sunlight; therefore, it must be stored in a refrigerator between 2-8°C. 10 A descriptive study on the evaluation of insulin pen knowledge and skills of people with diabetes was conducted at an outpatient clinic in a hospital in Turkey. The favorable results were that, among participants, there was a high percentage of knowledge on how to properly store insulin pens and insulin while traveling (82.5%); how to store insulin in the right conditions (82.5%); how to store insulin in the refrigerator at 2-8°C when the room temperature was over 28°C (83.5%); and how to store unused pens and insulin in the refrigerator (97%).…”