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A Methodology to Study Impactor Particle Reentrainment and a Proposed Stage Coating for the NGI.

Rissler, Jenny LU ; Asking, Lars and Dreyer, Jakob Kisbye (2009) In Journal of Aerosol Medicine and Pulmonary Drug Delivery 22(3). p.309-316
Abstract
Abstract Background: Mass-weighted aerodynamic particle-size distribution (APSD) is a key attribute for pharmaceutical products developed to deliver drugs to or through the lungs. In development and quality control, APSD is primarily determined using multistage cascade impactors. For impactor techniques, particle reentrainment is critical because it may lead to an overestimation of the respirable fraction. To avoid reentrainment, the collection surfaces need to be coated with a suitable material. Methods: In this study a method was developed to test flow dependence of particle reentrainment in the Next Generation Pharmaceutical Impactor (NGI) at flow rates ranging from 20 to 80 L/min, and was used to test three coating materials: glycerol... (More)
Abstract Background: Mass-weighted aerodynamic particle-size distribution (APSD) is a key attribute for pharmaceutical products developed to deliver drugs to or through the lungs. In development and quality control, APSD is primarily determined using multistage cascade impactors. For impactor techniques, particle reentrainment is critical because it may lead to an overestimation of the respirable fraction. To avoid reentrainment, the collection surfaces need to be coated with a suitable material. Methods: In this study a method was developed to test flow dependence of particle reentrainment in the Next Generation Pharmaceutical Impactor (NGI) at flow rates ranging from 20 to 80 L/min, and was used to test three coating materials: glycerol coating, aqueous coating with, and without soaked filter paper. Uncoated cups were also tested. In the experimental setup a Vilnius Aerosol Generator generated a flow-independent dry powder aerosol, consisting of micronized insulin. Results: The glycerol coating was not well suited to reduce particle reentrainment at flows >/=40 L/min. The soaked filter paper coating was found to give nearly the same particle size distributions regardless of flow and was therefore judged to be the best of those tested. Using liquid only, without the filter paper, gave the same particle size distributions as soaked filter paper for flows </=40 L/min, while at >/=60 L/min particle reentrainment increased with flow. However, for most applications liquid coating reduced particle reentrainment to an extent at which further reduction was irrelevant. Particle reentrainment was prevalent for uncoated cups at all flow rates tested. Conclusions: This study shows the advantage of using a stable and flow-independent aerosol generation method to examine particle reentrainment at various flows through the NGI. For insulin dry powder, the use of an aqueous solution as cup coating, preferably with a filter, reduced particle reentrainment to a minimum. The results were confirmed in a study with a DPI. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Aerosol Medicine and Pulmonary Drug Delivery
volume
22
issue
3
pages
309 - 316
publisher
Mary Ann Liebert, Inc.
external identifiers
  • wos:000272528700001
  • pmid:19415989
  • scopus:73849127356
ISSN
1941-2703
DOI
10.1089/jamp.2008.0735
language
English
LU publication?
yes
id
29c2fbe4-38cc-4f9e-83bf-178758b679a1 (old id 1412667)
date added to LUP
2009-06-11 12:13:08
date last changed
2017-07-23 03:50:19
@article{29c2fbe4-38cc-4f9e-83bf-178758b679a1,
  abstract     = {Abstract Background: Mass-weighted aerodynamic particle-size distribution (APSD) is a key attribute for pharmaceutical products developed to deliver drugs to or through the lungs. In development and quality control, APSD is primarily determined using multistage cascade impactors. For impactor techniques, particle reentrainment is critical because it may lead to an overestimation of the respirable fraction. To avoid reentrainment, the collection surfaces need to be coated with a suitable material. Methods: In this study a method was developed to test flow dependence of particle reentrainment in the Next Generation Pharmaceutical Impactor (NGI) at flow rates ranging from 20 to 80 L/min, and was used to test three coating materials: glycerol coating, aqueous coating with, and without soaked filter paper. Uncoated cups were also tested. In the experimental setup a Vilnius Aerosol Generator generated a flow-independent dry powder aerosol, consisting of micronized insulin. Results: The glycerol coating was not well suited to reduce particle reentrainment at flows &gt;/=40 L/min. The soaked filter paper coating was found to give nearly the same particle size distributions regardless of flow and was therefore judged to be the best of those tested. Using liquid only, without the filter paper, gave the same particle size distributions as soaked filter paper for flows &lt;/=40 L/min, while at &gt;/=60 L/min particle reentrainment increased with flow. However, for most applications liquid coating reduced particle reentrainment to an extent at which further reduction was irrelevant. Particle reentrainment was prevalent for uncoated cups at all flow rates tested. Conclusions: This study shows the advantage of using a stable and flow-independent aerosol generation method to examine particle reentrainment at various flows through the NGI. For insulin dry powder, the use of an aqueous solution as cup coating, preferably with a filter, reduced particle reentrainment to a minimum. The results were confirmed in a study with a DPI.},
  author       = {Rissler, Jenny and Asking, Lars and Dreyer, Jakob Kisbye},
  issn         = {1941-2703},
  language     = {eng},
  number       = {3},
  pages        = {309--316},
  publisher    = {Mary Ann Liebert, Inc.},
  series       = {Journal of Aerosol Medicine and Pulmonary Drug Delivery},
  title        = {A Methodology to Study Impactor Particle Reentrainment and a Proposed Stage Coating for the NGI.},
  url          = {http://dx.doi.org/10.1089/jamp.2008.0735},
  volume       = {22},
  year         = {2009},
}