Pressurized Metered Dose Inhaler-Based Analysis of Pulmonary Drug Delivery Using the Coupled Discrete Phase and Eulerian Wall Film Model

Abstract

This work uses the Eulerian wall film (EWF) and discrete phase model (DPM) to make a realistic prediction of drug deposition into the respiratory airways. The approach assumes that the tiny particles of liquid medication are inhaled, which after striking upon the lung airways, creates a thin quoting of drug substance. In this model, the EWF can resolve the drug layer deposition and their spread using the Eulerian approach to neutralize the respiratory virus. Thus, the current work can better predict the post-striking dynamics of drug layer spread, which previous studies were inadequate to predict. Parametric studies were made with three different particle sizes, 1 µm, 5 µm and 10 µm at the flow rates of 60, 30 and 15 litres per minute (LPM). It has been observed that in the fourth generation (G4), film thickness (FT) exhibits a 68.75% increase compared to G1 for 10 µm particles at a flow rate of 15 LPM. Whereas, at the G4 level, the 10 µm particles have a higher deposition efficiency compared to the 1 µm particles (10.4 times), and 5 µm sized particles(6.54 times). Hence, for effective patient treatment, it is always recommended that the particle size must vary between 5 and 10 µm. Less than 5 µm can cause health risks as they enter the deep lungs, whereas more than 10 µm can lead to deposits in the oral cavity.