In vitro dose comparison of Respimat® Soft Inhaler™ with dry powder inhalers for COPD maintenance therapy

Background: A head-to-head comparison of contemporary inhalers in real patients is difficult because of the variability inevitably introduced by the patients. Therefore in-vitro data on the dose passing the mouth-throat region was acquired using the realistic Alberta throat model. Three inhalers (Respimat®, Breezhaler®, and Genuair®) were compared. Providing flow profiles, the effect of the air flow rate can be well determined and its effect on the in vitro dose to the lung can be quantified. Methods: The flow resistances of all inhalers were determined. All three inhaler types were adapted to the inlet of the A…