Abstract
Introduction: Adjuvant therapy for laryngotracheal stenosis (LTS) include inhaled corticosteroids using metered dose inhalers, but these inhalers are designed for lower airway drug delivery.
Aims: This preliminary study seeks to determine stenotic particle deposition efficiency for orally inhaled drugs in LTS subjects with two stenotic sites.
Methods: Three-dimensional upper airway models were reconstructed from computed tomography images in two subjects. Stenotic sites were glottis and trachea in Subject 1, glottis and subglottis in Subject 2. Inhalation airflow and drug particle transport in the airway were simulated using computational fluid dynamics modeling. Three inhalation pressures were simulated, 10Pa, 25Pa, and 40Pa. Drug particle transport was simulated for 100-950 nanoparticles and 1-50 micron particles, with particles release into the mouth at velocities of 1m/s, 5m/s, and 10m/s.
Results: In Subject 1, maximal stenotic depositions were 0.86% (glottis) and 4.15% (trachea), occurring at 25Pa inhalation pressure with 1m/s actuation velocity. At the glottic stenotic site, 6-10 microns had the most deposition (2.66%), and 11-20 microns had the most deposition (13.25%) at the tracheal stenotic site. In Subject 2, maximal stenotic depositions occurred at 10Pa Inhalation pressure with 1m/s actuation velocity, and were 2.28% (glottis) and 1.93% (subglottis). At both stenotic sites, 11-20 microns had the most deposition, 7.28% (glottis) and 7.81% (subglottis).
Conclusions: Preliminary findings indicate that <4.2% of orally inhaled drug particles deposit at the stenosis, and particle size range with most stenotic deposition may not represent typical sizes emitted by inhalers.
Footnotes
Cite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 3187.
This abstract was presented at the 2020 ERS International Congress, in session “Respiratory viruses in the "pre COVID-19" era”.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
- Copyright ©the authors 2020