Dose accuracy of the redesigned follitropin alfa pen injector for infertility treatment

<b>Objectives:</b> The prefilled, multi-dose follitropin alfa (GONAL-f®) pen injector was redesigned based upon user feedback, to improve pen functionality. The dose information display was altered with the intention of improving readability and the dosing mechanism hardware was modified to increase robustness. The dose accuracy of the redesigned pen injector was evaluated under different conditions and after handling processes. <b>Methods:</b> Three studies investigated the dose accuracy of the three presentations (300, 450 and 900 IU) of the redesigned pen injector according to the ISO 11608-1:2012/2014 standard. The dose accuracy was evaluated in cold, standard and warm atmospheres, and subsequent to freefall, vibration, dry-heat, cold-storage and shipping preconditioning. The total extractable volume and dispense force of the pen injector were also investigated. <b>Results:</b> All doses dispensed with all three presentations, under all the conditions examined, were within the limits for accuracy defined by the ISO standard, as was the total extractable volume. The mean ± standard deviation dispense force was 12.5 ± 0.99 and 13.8 ± 1.16 N for the 300 and 900 IU pen injectors, respectively. These are below the upper threshold of the range considered optimal for pen injectors. <b>Conclusions:</b> These studies demonstrate that the redesigned pen injector functions reliably, dispensing accurate doses under the range of conditions studied.