Nebulized therapies for childhood pulmonary hypertension: An in vitro model
Objectives Sildenafil, tezosentan, and prostacyclin reduce pulmonary vascular pressures in pulmonary hypertension, but have potential to vasodilate the systemic circulation. Nebulized vasodilators allow targeted drug delivery, high local drug concentrations, less systemic hypotension, and better mat...
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Published in | Pediatric pulmonology Vol. 41; no. 7; pp. 666 - 673 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
Hoboken
Wiley Subscription Services, Inc., A Wiley Company
01.07.2006
Wiley-Liss |
Subjects | |
Online Access | Get full text |
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Summary: | Objectives
Sildenafil, tezosentan, and prostacyclin reduce pulmonary vascular pressures in pulmonary hypertension, but have potential to vasodilate the systemic circulation. Nebulized vasodilators allow targeted drug delivery, high local drug concentrations, less systemic hypotension, and better matching of the lung's ventilation and perfusion. We aimed to estimate pulmonary deposition of these drugs from commonly employed nebulizers using in vitro techniques and to create a mathematical model to predict inspired mass of aerosol.
Design
Lung deposition was estimated by characterization of drug output and particle size distribution (PSD) of nebulizers using helium‐neon laser diffraction techniques. A mathematical model for each device was created to estimate pulmonary deposition using patients' breathing patterns and was verified with a mechanical‐breathing model.
Results
Total output and PSD were similar for the Hudson Updraft II and Whisperjet nebulizers, consisting of half the nebulizer's charge, with ¼ of particles ≤5 µm, in the respirable fraction (RF). Drug output increased with inspiratory flow for the Pari LC Star. Differences were noted in device performance, depending on the drug tested. Estimated pulmonary deposition (mean, 95% CI) was 8.1 (7.2, 9.0)% of the initial drug charge for the Hudson Updraft II, 6.4 (5.8, 7.0)% for the Whisperjet, and 33.0 (28.3, 37.9)% for the Pari LC Star. A mechanical model was consistent with our mathematical model.
Conclusions
All drugs could be nebulized, but expected pulmonary deposition varied depending on the nebulizer and drug. Pediatr Pulmonol. 2006; 41: 666–673. © 2006 Wiley‐Liss, Inc. |
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Bibliography: | Dr. Allan Coates has served as a consultant for Pari Gmb. Dr. Ian Adatia has previously acted as a consultant to Actelion, Pfizer, and Glaxo-Welcome, but has no current affiliation. He has also been the recipient of an unrestrictive grant in aid from Pfizer. All other co-authors have no conflicts of interest. istex:DCB8D1E21152A17AEB8DEB87FBBA6856897F2A70 ArticleID:PPUL20431 This work was undertaken at The Hospital for Sick Children, Toronto, Ontario, Canada. ark:/67375/WNG-TVZ6RZ15-D Dr. Allan Coates has served as a consultant for Pari Gmb. Dr. Ian Adatia has previously acted as a consultant to Actelion, Pfizer, and Glaxo‐Welcome, but has no current affiliation. He has also been the recipient of an unrestrictive grant in aid from Pfizer. All other co‐authors have no conflicts of interest. ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 8755-6863 1099-0496 |
DOI: | 10.1002/ppul.20431 |