Beyond Particle Size: the impact of the breathing maneuvre

13. October 2025

Written by: Carolina Dantas (Medical & Scientific Affairs)

Is Aerosol Particle Size Really That Important?

When it comes to pulmonary drug delivery, aerosol particle size often gets most of the attention. Yet, as shown by Kirby Zeman and colleagues from the University of North Carolina at Chapel Hill, how a patient inhales can be just as decisive for where the drug ultimately deposits.

In their study published in the Journal of Aerosol Medicine and Pulmonary Drug Delivery (2010), the team investigated whether very large aerosol particles (9.5 μm MMAD) could effectively target the conducting airways when inhaled extremely slowly (4,8 L/min for 10 seconds).

The results revealed:

35% of the aerosol deposited in the conducting airways — compared to 27% with tidal breathing.
Extra thoracic losses dropped from 37% to 26%.

These findings demonstrate that breathing patterns matter as much as particle size. By slowing inhalation, large particles can reach the intended airways more efficiently while minimizing unwanted losses.

At PULMOTREE, we integrate these principles into our Kolibri™ Nebulizer Platform. With its feedback technology, the Kolibri™ guides the patient’s breathing manoeuvre in real time, supporting optimal aerosol deposition and consistent therapeutic outcomes.

📄 Zeman KL et al., Journal of Aerosol Medicine and Pulmonary Drug Delivery. 2010;23(6):363–369.

Learn more at www.pulmotree.com