title: Evaluation of enhanced condensational growth (ECG) for controlled respiratory drug delivery in a mouth-throat and upper tracheobronchial model.
abstract: OBJECTIVE
  The objective of this study is to evaluate the effects of enhanced condensational growth (ECG), as a novel inhalation drug delivery method, on nano-aerosol deposition in a mouth-throat (MT) and upper tracheobronchial (TB) model using in vitro experiments and computational fluid dynamics (CFD) simulations.
  
  
  METHODS
  Separate streams of nebulized nano-aerosols and saturated humidified air (39 degrees C-ECG; 25 degrees C-control) were combined as they were introduced into a realistic MT-TB geometry. Aerosol deposition was determined in the MT, generations G0-G2 (trachea-lobar bronchi) and G3-G5 and compared to CFD simulations.
  
  
  RESULTS
  Using ECG conditions, deposition of 560 and 900 nm aerosols was low in the MT region of the MT-TB model. Aerosol drug deposition in the G0-G2 and G3-G5 regions increased due to enhanced condensational growth compared to control. CFD-predicted depositions were generally in good agreement with the experimental values.
  
  
  CONCLUSIONS
  The ECG platform appears to offer an effective method of delivering nano-aerosols through the extrathoracic region, with minimal deposition, to the tracheobronchial airways and beyond. Aerosol deposition is then facilitated as enhanced condensational growth increases particle size. Future studies will investigate the effects of physio-chemical drug properties and realistic inhalation profiles on ECG growth characteristics.
authors.affiliation: Department of Pharmaceutics, Virginia Commonwealth University, 410 N. 12th St., P.O. Box 980533, Richmond, Virginia 23298-0533, USA. mhindle@vcu.edu
authors.forename: Michael
authors.initials: M
authors.lastname: Hindle
authors.forename: P Worth
authors.initials: PW
authors.lastname: Longest
mesh_terms: D000280:Administration, Inhalation; D000336:Aerosols; D000420:Albuterol / Q000008:administration & dosage; D001980:Bronchi / Q000033:anatomy & histology / Q000502:physiology*; D003198:Computer Simulation; D016503:Drug Delivery Systems / Q000379:methods*; D004867:Equipment Design; D006801:Humans; D008953:Models, Anatomic; D008954:Models, Biological; D009055:Mouth / Q000033:anatomy & histology / Q000502:physiology*; D053758:Nanoparticles / Q000008:administration & dosage; D009330:Nebulizers and Vaporizers; D010316:Particle Size; D010614:Pharynx / Q000033:anatomy & histology / Q000502:physiology*; D011237:Predictive Value of Tests; D014132:Trachea / Q000033:anatomy & histology / Q000502:physiology*
chemical_list: D000336:Aerosols; D000420:Albuterol
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