Dose accuracy comparison between SoloSTAR and FlexPen at three different dose levels

Background: The convenience and accuracy of insulin pens have led to their extensive use in patients with diabetes. Although all insulin pens go through extensive testing as part of the regulatory process, it is important that both the patient and clinician can be assured of the accuracy of the dose delivered. This study compared the dosing accuracy of two commonly available insulin pens, the SoloSTAR (R) (sanofi-aventis Deutschland GmbH, Frankfurt, Germany) and FlexPen (R) (Novo Nordisk A/S, Bagsvaerd, Denmark) devices. Methods: Doses of 5, 10, and 30 units of insulin were investigated for SoloSTAR and FlexPen, and specific units of accuracy were based on International Organization of Standards for insulin injection pens (+/- 1 unit for the 5 and 1.0-unit doses, +/- 5% for the 30-unit dose). A total of 30 pens were tested for both the SoloSTAR and FlexPen, and a total of 2,280 measurement values were taken for each pen type (5 units, 1,260; 10 units, 750; and 30 units, 270 doses). Results: Both devices were shown to be accurate at all three doses, and all doses were delivered within the limits proposed by the International Standard of Organization, which is used as part of the regulatory approval process when introducing an insulin injection device to the market. Conclusion: Our study shows that the SoloSTAR and FlexPen devices have comparable accuracy.