Volatile propellant droplet evaporation measurements in metered dose inhaler sprays

Metered dose inhalers (MDIs) have been used to deliver drugs to the lungs for over 60 years. MDIs rely on the flash-evaporation of a volatile propellant to create a fine aerosol. Since many classes of drugs are insoluble in the propellant, a co-solvent such as ethanol is often used. Predicting the evaporation of binary propellant-ethanol droplets is important in the development of new device designs and therapies. The need for improved measurements and predictive droplet models is highlighted by the need to rapidly transition away from hydrofluorocarbon propellants to low global warming potential propellants, which behave differently. In this study we develop a novel synchrotron X-ray scattering based method of measuring the composition of MDI droplets. When combined with droplet evaporation models, the data reveal the importance of internal diffusion-limiting processes in predicting binary droplet evaporation.

About the Speaker:
Dr Daniel Duke is a Senior Lecturer in the Department of Mechanical & Aerospace Engineering at Monash University, Australia. He holds a Bachelor of Engineering and Aerospace Technology (2008) and a PhD in Engineering from Monash University (2013).

Dr. Duke’s area of expertise is the fluid mechanics of aerosols and sprays, with a particular focus on pressurised metered dose inhalers. In his former role as a postdoctoral fellow at Argonne National Laboratory (USA) he developed of a range of novel synchrotron X-ray measurement approaches for cavitation and sprays. Dr. Duke’s current research interests span both experimental and simulation-based approaches to complex multi-phase, multi-component fluid flows.

Dr. Duke has published over 40 peer reviewed journal articles and over 50 refereed conference proceedings in the past decade. He leads the Multiphase flow research group in the Department of Mechanical & Aerospace Engineering at Monash University, supervising several PhD students and postdoctoral research fellows. Dr. Duke is a Fulbright fellow (2011), and an Australian Research Council DECRA Fellow (2017). He has been awarded over AUD 2.5M in competitive research grant funding, and is lead principal investigator on three active ARC projects in the field of cavitation and pharmaceutical sprays.