title: Effects of anatomy and particle size on nasal sprays and nebulizers.
abstract: OBJECTIVE
  To study the effects of nasal deformity on aerosol penetration past the nasal valve (NV) for varying particle sizes using sprays or nebulizers.
  
  
  METHODS
  Computed mathematical nasal airway model.
  
  
  METHODS
  Department computer lab.
  
  
  METHODS
  Particle deposition was analyzed using a computational fluid dynamics model of the human nose with leftward septal deviation and compensatory right inferior turbinate hypertrophy. Sprays were simulated for 10 µm, 20 µm, 50 µm, or particle sizes following a Rosin Rammler particle size distribution (10-110 µm), at speeds of 1, 3, or 10 meters per second. Nebulization was simulated for 1, 3.2, 6.42, or 10 µm particles. Steady state inspiratory airflow was simulated at 15.7 liters per minute.
  
  
  RESULTS
  Sprays predicted higher NV penetration on the right side for particle sizes >10 µm, with comparable penetration on both sides at 10 µm. Nearly 100% deposited in the nasal passages for all spray characteristics. Nebulizer predictions showed nearly 100% of particles <6.42 µm and more than 50% of 6.42 µm bypassing both sides of the nose without depositing. Of the nebulized particles that deposited, penetration was higher on the right at 10 µm, with comparable penetration on both sides at 6.42 µm. Spray penetration was highest at 10 µm, with more than 96% penetrating on both sides at 1 and 3 meters per second. Nebulization penetration was also highest at 10 µm (40% on the left, >90% on the right).
  
  
  CONCLUSIONS
  In the presence of a septal deviation, sprays or nebulizers containing 10-µm particles may have good penetration beyond the NV. Nebulized particles <10 µm are likely to be respirable. Additionally, spray speeds above 3 meters per second may limit penetration.
authors: Department of Otolaryngology/Head and Neck Surgery, University of North Carolina, Chapel Hill, North Carolina, USA.
authors: Dennis O
authors: DO
authors: Frank
authors: Julia S
authors: JS
authors: Kimbell
authors: Sachin
authors: S
authors: Pawar
authors: John S
authors: JS
authors: Rhee
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008962:Models, Theoretical; D059085:Nasal Sprays; D009330:Nebulizers and Vaporizers; D009666:Nose / Q000002:abnormalities*; D010316:Particle Size
chemical_list: D059085:Nasal Sprays