Improving usability and maintaining performance: human-factor and aerosol-performance studies evaluating the new...

Area of Science:

• Respiratory Medicine
• Pharmaceutical Technology
• Medical Device Design

Background:

• The Respimat soft-mist inhaler is a propellant-free device for medication delivery.
• Patient and physician observations led to the development of an improved, second-generation Respimat inhaler.
• Human-factor and in vitro aerosol performance studies are crucial for validating updated inhaler functionality.

Purpose of the Study:

• To assess the impact of the reusable Respimat inhaler's design on aerosol performance, specifically delivered dose (DD) and fine-particle dose (FPD).
• To iteratively evaluate and enhance the usability of the new reusable Respimat inhaler design.
• To compare the performance and usability of the reusable Respimat inhaler against the original disposable version.

Main Methods:

• The tiotropium-olodaterol inhalation solution was used as a model drug.
• Delivered dose (DD) and fine-particle dose (FPD) were measured using laser diffraction and an Andersen cascade impactor.
• Usability was assessed across three studies with healthcare professionals and patients (COPD, asthma, or combined disease), focusing on handling tasks and subjective feedback for iterative design optimization.

Main Results:

• Delivered doses of tiotropium and olodaterol remained stable across multiple cartridges and within the limits of the disposable Respimat.
• Fine-particle dose (FPD) was consistent across batches and comparable to the reference device.
• The reusable Respimat inhaler demonstrated improved usability in assembly and daily use, with cartridge exchange rated as intuitive and easy.

Conclusions:

• The reusable Respimat inhaler, with its enhanced features, meets the needs of healthcare professionals and patients.
• The design of the reusable Respimat does not compromise drug delivery across multiple cartridges.
• The reusable Respimat offers superior usability, convenience, and a reduced environmental footprint compared to the disposable Respimat inhaler.