Open AccessEffects of Anatomy and Particle Size on Nasal Sprays
Author(s) -
Frank Dennis,
Pawar Sachin,
Rhee John S.,
Kimbell Julia S.
Publication year - 2011
Publication title -
otolaryngology–head and neck surgery
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.232
H-Index - 121
eISSN - 1097-6817
pISSN - 0194-5998
DOI - 10.1177/0194599811416318a250
Subject(s) - penetration (warfare) , particle size , materials science , nasal spray , spray characteristics , geometric standard deviation , mechanics , physics , chemistry , nozzle , medicine , mathematics , aerosol , spray nozzle , meteorology , thermodynamics , nasal administration , operations research , immunology
Objective Compare spray penetration past the nasal valve (NV) predicted for particle sizes at varying spray speeds using a computational fluid dynamics (CFD) model of the human nasal cavity with septal deviation on the left side and inferior turbinate hypertrophy on the right. Method Simulations using Fluent (ANSYS, Inc, Lebanon, New Hampshire) were carried out for 10 µm, 20 µm, 50 µm, or particle sizes following a Rosin Rammler Particle Size Distribution (RRPSD) ranging from 10‐110µm. Spray speed was 1 m/s, 3 m/s, or 10 m/s; steady state inspiratory airflow rate was 15.7 L/min. Results Simulations predicted at least 2 times higher NV penetration on the right side (hypertrophic turbinate) than the left (septal deviation) for most particle sizes and spray speeds. Simulated penetration of 10 µm particles at 1 m/s was 100% with none escaping via the nasopharynx. At 3 and 10 m/s, more simulated 10µm particles escaped the nose than other sizes. Maximum penetration of RRPSD, 20µm, and 50µm particles was predicted to be 15%, 35%, and 12% on the left side, and 52%, 58%, and 56% on the right, respectively, occurring at 1m/s for RRPSD and 50 µm, and 3 m/s for 20 µm. Conclusion In the presence of a septal deviation, sprays containing 10 µm particles may have better penetration past the NV. Additionally, increasing spray speed (above 3m/s) appears to limit spray penetration, suggesting that patients should be discouraged from spraying medications forcefully, as this could limit penetration of the drug.