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