Deposition of Corticosteroid Aerosol in the Human Lung by Respimat® Soft Mist™ Inhaler Compared to Deposition by Metered Dose Inhaler or by Turbuhaler® Dry Powder Inhaler

Fourteen mild-to-moderate asthmatic patients completed a randomized four-way crossover scintigraphic study to determine the lung deposition of 200 µg budesonide inhaled from a Respimat® Soft Mist™ Inhaler (Respimat® SMI), 200 µg budesonide inhaled from a Turbuhaler ® dry powder inhaler (Turbuhaler® DPI, used with fast and slow peak inhaled flow rates), and 250 µg beclomethasone dipropionate inhaled from a pressurized metered dose inhaler (Becloforte® pMDI). Mean (range) whole lung deposition of drug from the Respimat® SMI (51.6 [46–57]% of the metered dose) was significantly (p < 0.001) greater than that from the Turbuhaler® DPI used with both fast and slow inhaled flow rates (28.5 [24–33]% and 17.8 [14–22]%, respectively) or from the Becloforte® pMDI (8.9 [6–12]%). The deposition pattern within the lungs was more peripheral for Respimat® SMI than for Turbuhaler® DPI. The results of this study showed that Respimat® SMI deposited corticosteroid more efficiently in the lungs than either of two widely used inhaler devices, Turbuhaler® DPI or Becloforte® pMDI.