Investigation of Drug Delivery Rate of Three Different Nebulizers Using a Lung Simulator
Taewon Han, Michael Falvo, Daniel P. Wilhite, GEDIMINAS MAINELIS, Rutgers, The State University of New Jersey
Abstract Number: 193
Working Group: Health-Related Aerosols
Abstract
Pulmonary function laboratories are increasingly adopting dose rather than concentration for reporting methacholine challenge test results. One of the key parameters of nebulizers used in such tests is their drug delivery rate (mg/min). This project analyzed the delivery rate of three popular medical nebulizers: AeroEclipse® II BAN®, Hudson RCI® MicroMist®, and Vyaire Misty Max 10™.
Each nebulizer was connected to a pulmonary function testing filter, and different breathing patterns, including tidal volume, breathing rate, lung compliance, and lung resistance, were simulated using a lung simulator (Michigan Instruments, MI). The aerosol delivery rate was determined by measuring the mass of methacholine (Provocholine®) captured on the filter. The delivery rate depended on the nebulizer model, operation time, initial drug concentration, and initial liquid volume. When AeroEclipse® II BAN® aerosolized 16 mg/ml of Provocholine® from 3 mL of initial solution, the delivery rate decreased from 7.1 mg/min to 5.5 mg/min as the delivery time increased from 20 seconds to 2 minutes. For the same drug concentration of 16 mg/min and a 2-minute operation time with an initial 3 mL drug solution, the MicroMist® and Misty Max™ nebulizers demonstrated delivery rates of 3.1 ± 0.3 and 2.87 ± 0.3 mg/min, respectively, which were lower than the AeroEclipse® II BAN®’s 5.5 ± 0.5 mg/min. This delivery rate by AeroEclipse II® BAN® is about 2x higher than advertised by its manufacturer. Also, the tidal volume was positively correlated with the delivery rate.
Thus, selecting a nebulizer can significantly affect the delivered drug dose, which is determined by the product of delivery rate and delivery time. with implications for methacholine challenge tests and resulting asthma diagnoses.