PRESSURE-DROP ACROSS INHALATION AEROSOL ACTUATORS - INFLUENCE OF POSITION AND AREA FOR AIR PASSAGE

When a patient inhales through an aerosol actuator, there is a resistance to air flow causing a pressure drop across the unit. The pressure drop can be reduced by increasing the area for air passage either in the space between container and actuator, or by using openings in the actuator wall. Both alternatives were investigated and there were only small differences among the positions tested. The area for air passage was the main determining factor. The pressure drop across a new actuator design could be predicted accurately by using a friction loss factor obtained from available results for the original actuator. © 1979.