Technique for aerosol deposition restricted to the nose in beagle dogs

Abstract

A method was developed for exposing the nasal cavity of beagle dogs to a radiolabeled aerosol without exposure of the remainder of the respiratory tract. Deposition efficiency, using a test aerosol of 2.0‐iim particles of ^99mTc‐sulfur colloid delivered to the nose, was 15 ± 2% (mean ± SE) of inhaled activity. Camma camera imaging showed that maximum deposition occurred in the anterior third of the nasal cavity, which contained 78 ± 4% (mean ± SE) of the total deposited radioactivity. The middle third of the nasal cavity received 13 ± 3% and the posterior third 9 ± 2% of the deposited radioactivity. Aerosol deposition in regions of the respiratory tract below the larynx was not detectable.