Characterization of Aerosol Deposition in Children and Infants Using Idealized Extrathoracic Geometries

• Author / Creator

  Ruzycki, Conor A.

• This thesis describes a number of experimental studies performed with the common goal of characterizing pharmaceutical aerosol deposition in children and infants using idealized extrathoracic geometries. First, an in vitro study of the recently proposed Alberta Idealized Child Throat showed that this idealized child oral extrathoracic airway model accurately replicates average deposition of pharmaceutical aerosol from pressurized metered dose inhalers and dry powder inhalers in school age children. This successful validation confirms that the Alberta Idealized Child Throat may indeed fulfill the existing requirement for a standardized platform in which benchtop testing of delivery devices and therapeutic formulations developed for children can be examined. Second, a joint in vitro – in silico methodology was employed to characterize deposition in an idealized infant nasal extrathoracic airway geometry. Using a novel flow system, total lung dose from two pressurized metered dose inhalers, delivered via valved holding chamber and facemask under a realistic breath profile, was approximated by the dose delivered distal to the idealized geometry. In silico simulations using this estimate of total lung dose provided insight on regional deposition in the lungs and on the concentration of drug in the airway surface liquid. From a clinical perspective, this in vitro – in silico methodology provides valuable guidance on the dosing required for efficacious use of aerosolized medications in infants. Finally, a comparison of in vitro deposition measured in two idealized geometries representative of the oral extrathoracic airways of children is described, illustrating the importance of considering the physics governing aerosol behavior in the human airways when developing idealized geometries meant to mimic in vivo deposition. It is hoped that the experiments undertaken as part of this thesis will aid in the development of new delivery devices and inhalation therapies for the treatment of disease in children and infants.

• Subjects / Keywords

  • Children
  • In vitro
  • Pharmaceutical aerosol
  • Idealized geometries
  • Infants
  • Deposition

• Graduation date

  Fall 2014

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3Z390

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.