Usability and Robustness of the Wixela Inhub Dry Powder Inhaler

Background: Wixela Inhub is a generic version of Advair Diskus recently approved by the U.S. Food and Drug Administration. The Inhub inhaler delivers fluticasone propionate (FP)/salmeterol in a dry powder formulation. The goals of our studies were to demonstrate that the Inhub inhaler can be used by representative end users and confirm the robustness of the Inhub inhaler. Methods: Study 1: A nondosing usability assessment, the device orientation study, confirmed that intended users (represented by patients diagnosed with asthma or chronic obstructive pulmonary disease [COPD] who were naive to dry powder inhalers and current Advair Diskus users) could use the Inhub inhaler safely and effectively. Subjects were provided with an Inhub inhaler in commercial packaging, including instructions for use, and were asked to undertake three dose simulations using the inhaler. Subjects were encouraged to interact with this new drug delivery device as they would at home. Subjects were not provided with training on the use of the device. Subjects were observed interacting with the Inhub inhaler, and those who currently use Diskus were also observed interacting with the Diskus to determine whether their mental model of the use of Diskus impacted their interaction with the Inhub device, this assessment was not a primary outcome of the study. Study 2: This is an open-label clinical study to confirm the robustness of the Inhub inhaler after at home patient use. Subjects diagnosed with asthma or COPD were provided Inhub inhaler training and subsequently self-administered 3 weeks of twice daily doses of Wixela Inhub 250 μg FP/50 μg salmeterol in the home environment. The Inhub inhalers were returned to the investigator after ∼3 weeks of outpatient use for in vitro tests on the drug remaining in each inhaler. Results: Study 1 enrolled 110 subjects, and all completed the study. Most subjects (100/110) held the Inhub inhaler in the correct orientation and of those who did not, 9 still achieved a peak inhalation flow rate of ≥30 L/min and a total inhaled volume of ≥1 L, thus meeting the requirements of the study success criteria. In Study 2, 111 pediatric, adult, and elderly subjects with asthma or COPD received the study drug. After ∼3 weeks of outpatient use of the Inhub inhaler by subjects, comprehensive in vitro testing demonstrated that the FP and salmeterol pharmaceutical performance in the Inhub inhaler was preserved. Conclusions: The majority of subjects demonstrated safe and effective use of the Inhub inhaler. In vitro testing and inspections confirmed the robustness of the Inhub inhaler after outpatient use. Clinical trial registration number: NCT02474017