An ex vivo study was designed to compare the dosing efficiency of different inhaler devices (soft mist inhaler [SMI], pressurized metered dose inhaler [pMDI] and dry powder inhaler [DPI]) and investigate their robustness to inhaler orientation. Stiolto® Respimat® SMI, Trimbow® pMDI, Fostair NEXThaler® DPI and Trelegy Ellipta® DPI were each tested using the Alberta Idealized Throat model, with realistic inhalation patterns for very severe COPD generated by a lung simulator.
The in vitro distribution of dose to the mouth/oropharynx and availability to the lungs were assessed with the inhalers adapted to the throat model in the normal upright orientation and effectively leaning forward at a 45-degree angle. The Stiolto Respimat SMI was superior in dosing efficiency and dose to the lungs compared with Trelegy Ellipta DPI, Fostair NEXThaler DPI and Trimbow pMDI. Irrespective of the inhaler position, the Stiolto Respimat SMI was associated with the lowest dose to the mouth/oropharynx and the highest dose delivered to the lungs. These benefits are expected to translate into the robustness of Stiolto Respimat SMI in routine clinical use, ensuring consistently high dose delivery to the lungs even when patients do not follow instructions regarding inhaler orientation.