A comparison of the regional deposition in a model nose of a drug discharged from metered aerosol and metered-pump nasal delivery systems.
The morphology and airflow behavior in the nose are considered briefly in relationship to the various ways that are often used to evaluate the spray or aerosol discharged from inhalation delivery systems. A glass-model nose of a design based on published anatomic measurements is described. Its use is described for examining the major sites of drug deposition from nasal delivery systems. That no significant differences are detected between the regional deposition from a metered aerosol and a metered-pump product confirm what might be expected from the nasal anatomy. Most of the drug in each case is deposited in the anterior region of the nose by inertial impaction, and there is little nasal penetration of the drug. Inhaled airflow at 10 L/min through one side of the nose has little effect on regional deposition. The anteriorly deposited drug can be spread backward by mucociliary flow and general surface flow, factors that are essentially independent of the presentation used.