The Impact of Possible Misuses Conditions on in Vitro Performance of NEXThaler in Comparison with Ellipta Inhaler

: The correct use of dry powder inhalers by the patients is essential to ensure effective treatment and management of the disease. The purpose of the work was to assess the consequence of inhaler misuse in terms of emitted dose and aerodynamic parameters. One reservoir multidose (Foster-NEXThaler®) and one pre-dosed (Relvar-Ellipta®) devices, both sharing the "open, inhale and close" procedure, were the subject of the study. NEXThaler activated at different degrees of slope showed a consistent dose delivery for both the drugs included in the formulation (beclomethasone dipropionate/formoterol fumarate). Contrary, Ellipta showed a decrease of the emitted dose for both fluticasone furoate and vilanterol trifenatate when the device was operated with inclination (-14% at 45° and -22% at 90°). Similarly, the delivered dose of NEXThaler was unaffected by an accidental fall, while Ellipta released FluF and VT doses 50% lower than the control values. The presence of the dose protector in NEXThaler offers the advantage of retaining the powder if the inhaler is subjected to incorrect manipulations. Both products proved to be reliable in double activation. Finally, simulation exhalation conditions had an impact on the aerodynamic profile of the two products.