Reusable soft mist inhaler: maintaining aerosol performance

Abstract

Introduction: The disposable Respimat® inhaler has been updated to use with up to six cartridges. For the reusable Respimat inhaler, aerosolization design and solution composition were not changed. Aims: To investigate whether aerosol performance (delivered dose and fine particle dose [FPD]) of the reusable Respimat inhaler remained unchanged versus disposable Respimat following multiple cartridge changes. Methods: The tiotropium/olodaterol inhalation solution for Respimat was used as model solution. The delivered dose and FPD were each tested in a one-time study with a reference from a disposable Respimat inhaler compared with nine cartridges from the reusable Respimat inhaler. FPD was determined by routine laser diffraction and with the alternative Andersen Cascade Impactor. Results: Data show that the delivered doses of tiotropium and of olodaterol over nine cartridges were stable, and consistently within the upper and lower limits of the reference device. FPD was also shown to be batch consistent over the cartridges and comparable with the reference (Figure). Conclusion: Performance in terms of delivered dose and FPD remained unchanged after modifications to the Respimat inhaler. Results prove excellent stability of reusable Respimat inhaler performance even when used for nine cartridges. Batch-to-batch variability was minimal and remained within the reference limits. Patients can be reassured that their treatment quality is maintained with the updated device.