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Beth L. Laube. 1 The Johns Hopkins Medical Institutions, Baltimore, Maryland.
Gail Sharpless. 1 The Johns Hopkins Medical Institutions, Baltimore, Maryland.
Ami R. Vikani. 2 The George Washington University School of Medicine and Health Sciences, Washington, District of Columbia.
Vincent Harrand. 3 CFD Research Corporation, Huntsville, Alabama.
Simeon J. Zinreich. 1 The Johns Hopkins Medical Institutions, Baltimore, Maryland.
Keith Sedberry. 3 CFD Research Corporation, Huntsville, Alabama.
Darin Knaus. 4 Creare, LLC, Hanover, New Hampshire.
James Barry. 4 Creare, LLC, Hanover, New Hampshire.
Mark Papania. 5 Centers for Disease Control and Prevention, Atlanta, Georgia.
* The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention.
Reviewed by: Hettie Janssens, Winfried Möller
Address correspondence to: Beth L. Laube, PhD, Johns Hopkins Hospital Park, The David M. Rubenstein Building, 200 North Wolfe Street, Suite 3015, Baltimore, MD 21287, E-mail: [email protected]
Introduction
In vivo intranasal deposition of aerosolized medications delivered by spray pumps, liquid droppers, pressurized meter dose inhalers (pMDIs), dry powder inhalers, and nebulizers has been quantified in adults.(1-5) This is often accomplished by adding a gamma emitting radioisotope to the formulation to be aerosolized, followed by quantification of the amount of isotope that is deposited in the intranasal airways of volunteers using gamma scintigraphy. Another approach has been to administer an aerosol containing a blue dye, or fluorescein, followed by visualization of the intranasal distribution using nasal endoscopy. From all of these studies, we know that spray pump droplets >10 μm and droplets generated from pMDIs primarily deposit in the anterior portion of the nose, including the nasal floor and the lower turbinate region.(1,2,6-9) Droplets generated from liquid droppers appear to distribute equally along the nasal floor(9,10) between non-ciliated and ciliated regions, and nebulizers deposit aerosol more uniformly with deposition in anterior and posterior regions and inferior and superior regions of the nose.(5)
Ethical concerns often prohibit exposure of children to radioisotopes and endoscopy procedures for imaging purposes. In addition, infants and young children can be non-compliant during deposition studies, making in vivo quantification difficult. For this reason, very little is known about the deposition of aerosolized medications in the intranasal airways of infants...