title: High resolution visualization and analysis of nasal spray drug delivery.
abstract: OBJECTIVE
  Effective nasal drug delivery of new-generation systemic drugs requires efficient devices that can achieve targeted drug delivery. It has been established that droplet size, spray plume, and droplet velocity are major contributors to drug deposition. Continual effort is needed to better understand and characterise the physical mechanisms underpinning droplet formation from nasal spray devices.
  
  
  METHODS
  High speed laser photography combined with an in-house designed automated actuation system, and a highly precise traversing unit, measurements and images magnified in small field-of-view regions within the spray was performed.
  
  
  RESULTS
  The qualitative results showed a swirling liquid sheet at the near-nozzle region as the liquid is discharged before ligaments of fluid are separated off the liquid sheet. Droplets are formed and continue to deform as they travel downstream at velocities of up to 20 m/s. Increase in actuation pressure produces more rapid atomization and discharge time where finer droplets are produced.
  
  
  CONCLUSIONS
  The results suggest that device designs should consider reducing droplet inertia to penetrate the nasal valve region, but find a way to deposit in the main nasal passage and not escape through to the lungs.
authors.affiliation: School of Aerospace, Mechanical and Manufacturing Engineering, RMIT University, PO Box 71, Bundoora, VIC, 3083, Australia.
authors.forename: Kiao
authors.initials: K
authors.lastname: Inthavong
authors.forename: Man Chiu
authors.initials: MC
authors.lastname: Fung
authors.forename: Xuwen
authors.initials: X
authors.lastname: Tong
authors.forename: William
authors.initials: W
authors.lastname: Yang
authors.forename: Jiyuan
authors.initials: J
authors.lastname: Tu
mesh_terms: D000281:Administration, Intranasal; D016503:Drug Delivery Systems / Q000295:instrumentation* / Q000379:methods; D059085:Nasal Sprays; D009330:Nebulizers and Vaporizers; D004364:Pharmaceutical Preparations / Q000008:administration & dosage / Q000737:chemistry*; D010781:Photography / Q000295:instrumentation / Q000379:methods
chemical_list: D059085:Nasal Sprays; D004364:Pharmaceutical Preparations