The impact of actuator nozzle and surroundings condition on drug delivery using pressurized-metered dose inhalers

The most commonly used method to deliver aerosolized drugs to the lung is with pressurized metered-dose inhalers (pMDIs). The spray actuator is a critical component of pMDI, since it controls the atomization process by forming aerosol plumes and determining droplet size distribution. Through computational fluid dynamics (CFD) simulations, this study investigated the effect of two different nozzle types (single conventional and twin nozzles) on drug deposition in the mouth-throat (MT) region. We also studied the behavior of aerosol plumes in both an open-air environment and the MT geometry. Our study revealed that spray aerosol generated in an unconfined, open-air environment with no airflow behaves distinctly from spray introduced into the MT geometry in the presence of airflow. In addition, the actuator structure significantly impacts the device's efficacy. In the real MT model, we found that the twin nozzle increases drug deposition in the MT region, and its higher aerosol velocity negatively affects its efficiency.