| Abstract: | The initial distribution and subsequent clearance of aerosol from a hand-operated nasal pump spray has been assessed from gamma camera scans in ten normal subjects, following labelling of placebo sprays with 99Tcm labelled Teflon particles (mean diameter 2 micron). Aerosol was concentrated chiefly in the anterior part of the nose, but the area of deposition varied between subjects. No particles reached the lungs. A mean 56% of the dose was retained at the initial site of deposition 30 minutes after administration, while the remaining 44% of the dose had cleared to the nasopharynx. The initial partitioning of nasal pump sprays between ciliated and non-ciliated zones is relevant both for effective topical therapy of the nasal cavity, and for possible systemic drug delivery by the intranasal route. |
