Design, validation and initial testing of the Electronic LungTM device

The Electronic LungTM Device (ELD) is an inhalation simulator designed to provide an in vitro assessment of dry powder inhalers (DPIs), and is used as a research and development tool. The ELD ‘inhales’ through an inhalation device, following a preprogrammed theoretical or patient inhalation profile, and the resultant aerosol cloud is analysed for dose and particle size. This paper describes the design and validation of the ELD. The validation work shows that respirable particle losses are low in the ELD and the particle size and dose results are comparable with other in vitro testing methods for DPIs. The performance of Serevent Diskus§ inhaler is evaluated using computer-generated inhalation profiles. Comparison with results using a cascade impactor alone, show that the ELD itself does not affect the aerosol quality, either in terms of emitted dose or fine particle dose and consistent dosing performance is achieved over a range of inhalation parameters.