Dose accuracy and durability of a durable insulin pen before and after simulated lifetime use.

BACKGROUND AND OBJECTIVE: NovoPen Echo* is an insulin pen designed specifically for children and adolescents with diabetes. The pen combines half-unit dosing and a simple memory function that records the size of the last dose and the time in hours that has elapsed since last injection. Durability is an essential feature of durable insulin pens in order to ensure accuracy throughout the lifetime of the pen. This study was designed to assess dose accuracy and durability of NovoPen Echo before and after simulated lifetime use. RESEARCH DESIGN AND METHODS: All testing was conducted according to International Organization for Standardization (ISO) guideline 11608-1 for pen injectors. Dose accuracy was measured for the delivery of 0.5 international units** (IU) (5 mg), 15 IU (150 mg) and 30 IU (300 mg) test medium before and after lifetime simulation under standard, cool and hot conditions. Functionality tests were also performed under a number of stress conditions including dry heat, cyclical temperature, vibration, free fall and electrostatic discharge. RESULTS: The dose accuracy of NovoPen Echo meets the requirement stated in ISO 11608-1 for all three doses for all tests before and after lifetime simulation. The pens remained intact and retained dosing accuracy at all doses after exposure to variations in temperature and humidity and before and after physical challenge to simulate lifetime use. CONCLUSIONS: The accuracy of NovoPen Echo was retained under conditions of stress likely to be encountered in everyday use due to its durable design.

Dose accuracy and durability of the NovoPen 4 insulin delivery device before and after simulation of 5 years of use and under various stress conditions.

OBJECTIVE: The dose accuracy of the NovoPen 4 (Novo Nordisk A/S, Bagsvaerd, Denmark) insulin delivery device was evaluated before and after simulation of 5 years of use and under conditions of mechanical and temperature stress. METHODS: To simulate 5 years of use of the NovoPen 4, > or =5475 injections were performed automatically, corresponding to 3 daily injections for 5 years. Accuracy in the delivery of 1-, 30-, and 60-U insulin doses before and after simulation of 5 years of use was assessed over the in-use temperature range (5 degrees C-40 degrees C [41 degrees F-104 degrees F]). The durability and dose accuracy of the NovoPen 4 were also assessed after exposure to extremes of temperature (-40 degrees C and 70 degrees C), high relative humidity (95% RH), and mechanical challenges (freefall from 1.5 m at ambient temperature and from 1 m at 5 degrees C, 40 degrees C, and 95% RH). RESULTS: The dose accuracy of the NovoPen 4 before and after 5 years of simulated use was within International Organization for Standardization 11608-specified limits for all doses studied. Dose accuracy remained within specifications for all doses after exposure to variations in temperature and humidity, and after freefall. CONCLUSION: The NovoPen 4 exhibited dose accuracy before and after simulation of 5 years of use, across a wide range of temperature and humidity conditions, and after mechanical challenges.

Accuracy and precision of the NovoPen 3 insulin delivery device after mechanical and temperature stresses.

OBJECTIVE: To evaluate the precision, accuracy, and durability of an insulin pen injection device (NovoPen 3) at three preset doses (2 IU, 35 IU, and 70 IU) after exposure to various stress and durability tests that were intended to simulate daily use by patients. METHODS: Twenty-nine reusable NovoPen 3 insulin delivery devices were tested. The precision and accuracy of 10 insulin pen devices were evaluated after they were subjected to multiple thermal and vibration stress tests. Another 10 pen devices were subjected to a free-fall test. Nine other insulin pens were subjected to endurance testing that simulated 5 years of injections. RESULTS: The accuracy (as measured by the relative error of the delivered dose of insulin) of the insulin pen injection devices was within 1% of the preset dose after all stress or endurance tests. A free-fall test produced no indication of damage except for broken clips and snap catches on the caps, which did not affect the integrity or performance of the insulin pens. The precision of the pen devices (as measured by relative standard deviations of delivered volumes of insulin) was likewise high after thermal stress, vibration stress, free-fall testing, or 5-year endurance testing. CONCLUSION: Overall, this study showed that the insulin pen injection devices tested were durable under conditions of stress likely to be encountered in daily patient use. Neither a wide variety of repetitive stresses nor insulin injection cycles corresponding to 5 years of use affected the accuracy or precision enough to have clinical significance for reliable insulin delivery.