The Effect of Nasal Patency on the Clearance of Radiolabeled Saline in Healthy Volunteers

Abstract

Purpose. The objective of this study was to investigate the effect ofnasal cavity patency on the penetration, deposition, and clearance ofan aqueous isotonic saline solution.

Methods. The study was carried out as a single center, open,randomized, 2-way cross-over in healthy volunteers. Nasal patency wasassessed using misting patterns on a cold metal surface at the beginningand end of study. 100 μl of technetium-99m radiolabeled saline solutionwas introduced into either the most or least patent nasal cavity usinga purpose designed spray device. The distribution and residence timeof the radiolabel was followed for 2 hours using gamma scintigraphy.

Results. The mean times to 50% clearance were34 ± 7 and 28 ± 12minutes (±s.d.) for the side view of the least and most patent nasalcavity respectively. Total clearance of the radiolabelled saline from thenose was not affected by patency. Between 7 and 3% of theradiolabelled saline solution remained in the nasal cavity at the end of imaging.Using endoscopy to track the clearance of an aqueous solution of fooddye using the same delivery procedure, identified this region as hairin the nasal vestibule. The dye was seen to dry in this region alongwith the mucus.

Conclusions. Nasal patency affects the initial, but not total clearanceof solutions, however, the remaining solution may not be available fordrug delivery.