Assessment and Validation of a Hygroscopic Growth Model with Different Water Activity Estimation Methods

Details

• Personal Author:
  Altmaier R ; LeBlanc L ; Lin C-L ; O'Shaughnessy PT ; Pratt A ; Rajaraman PK ; Walenga R
• Description:
  Hygroscopic growth models are currently of interest as aids for targeting the deposition of inhaled drug particles in preferred areas of the lung that will maximize their pharmaceutical effect. Mathematical models derived to estimate hygroscopic growth over time have been previously developed but have not been thoroughly validated. For this study, model validation involved a comparison of modeled values to measured values when the growing droplet had reached equilibrium. A second validation process utilized a novel system to measure the growth of a droplet on a microscope coverslip relative to modeled values when the droplet is undergoing the initial rapid growth phase. Various methods currently used to estimate the water activity of the growing droplet, which influences the droplet growth rate, were also compared. Results indicated that a form of the hygroscopic growth model that utilizes coupled-differential equations to estimate droplet diameter and temperature over time was valid throughout droplet growth until it reached its equilibrium size. Accuracy was enhanced with the use of a polynomial expression to estimate water activity relative to the use of a simplified estimate of water activity based on Raoult's Law. Model accuracy was also improved when constraining the film of salt solution surrounding the dissolving salt core at saturation. [Description provided by NIOSH]
• Subjects:
  Aerosols Air Pollutants, Occupational Biopharmaceutics Lung Occupational Health Respiratory System Safety
• Keywords:
  Aerosol Particles Airborne Particles Analytical Models Biological Effects Chemical Deposition Drugs Growth Rate Health Effects Inhalation Lung Function Mathematical Models Models Particle Diameter Performance Tests Pharmaceuticals Temperature Measurement Water Analysis

  More +
• ISSN:
  0278-6826
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Iowa ; Maryland ; OSHA Region 3 ; OSHA Region 7
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  54
• Issue:
  10
• NIOSHTIC Number:
  nn:20061358
• Citation:
  Aerosol Sci Technol 2020 Oct; 54(10):1169-1182
• Contact Point Address:
  Patrick T. O'Shaughnessy, Department of Occupational and Environmental Health, 100 CPHB, S320, Iowa City, IA 52242 USA
• Email:
  patrick-oshaughnessy@uiowa.edu
• Federal Fiscal Year:
  2021
• Performing Organization:
  University of Iowa
• Peer Reviewed:
  True
• Start Date:
  20050701
• Source Full Name:
  Aerosol Science and Technology
• End Date:
  20290630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:ed4b1f08299c655cdbc160f4a5491174f1826e181bf0b15b3c6a779b3fd8ebbb920f61a81ceab87ff8bdedb66ab9c45bf4c43ab70eec053812ea40e586cb4094
• Download URL:
  https://stacks.cdc.gov/view/cdc/224903/cdc_224903_DS1.pdf
• File Type:
  [PDF - 2.11 MB ]