Differences in the dose accuracy of insulin pens

Abstract

Background: Modern insulin injection pens provide a convenient and accurate way for diabetes patients to inject insulin. They have widespread use among children and adults with type 1 and type 2 diabetes in the U.S. and Europe. This study compared the dosing accuracy of four commonly available insulin pens (OptiClik® and SoloSTAR® from sanofi-aventis, FlexPen® from Novo Nordisk, and HumaPen® LUXURA" from Eli Lilly). Methods: The dosing accuracy was tested for all pens with 24 × 10 IU and 9 × 30 IU injection volumes to investigate whether the pens complied with the acceptable International Organization for Standardization (ISO) limits of 10% (± 1 IU) for 10 IU and 5% (± 1.5 IU) for 30 IU. The doses were each applied with a new needle strictly according to the instructions for use by the pen manufacturers. A pharmaceutical balance was used for the assessment of the applied volumes, and the results were corrected for the specific density of the insulin formulations. Four in}sulin pens (two each from different production lots) were used for each of the two volumes, resulting in a total of 192 doses per pen with 10 IU, and 72 doses per pen with 30 IU. Results: FlexPen (mean absolute percent deviation for 10 IU and 30 IU: 1.64 ± 0.84% and 0.83 ± 0.26%, respectively) and HumaPen LUXURA (1.10 ± 0.20% and 0.62 ± 0.19%; not significant versus FlexPen for both doses) were more accurate than the OptiClik (4.78 ± 3.31% and 2.97 ± 2.48%, p