In Vitro Evaluation of Aerosol Delivery by Hand-Held Mesh Nebulizers in an Adult Spontaneous Breathing Lung Model

Background: Drug inhalation is common mode of treatment for chronic obstructive pulmonary disease (COPD). The aim of this study was to evaluate the efficiency of aerosol devices in a simulated COPD adult lung model using five commercially available hand-held mesh nebulizers. Materials and Methods: Five nebulizers (PARI VELOX®, Omron NE-U22, Aeroneb® Go, APEX PY001, and Pocket Air®) were tested with a unit dose of 5.0 mg/2.5 mL salbutamol. An in vitro lung model (compliance: 0.06 L/cm H2O, resistance: 20 cm H2O/L/sec) was constructed to simulate parameters (tidal volume of 500 mL, respiratory rate of 15 breaths/min, inspiratory time of 1 second) of an adult patient with COPD. A bacterial filter was attached at the bronchi level for drug collection, referring as inhaled mass. After nebulization, the inhaled mass (%), dose remaining on each component (%), particle size characteristics, and nebulizer performances were analyzed. Particle size characteristics were analyzed using an 8-stage Anderson Cascade Impactor. The salbutamol particles deposited were eluted and analyzed using a spectrophotometer at 276 nm. The inhaled mass (%), dose remaining on each component (%), particle size distribution, and nebulizer performance were statistically analyzed using analysis of variance (ANOVA) with Sheffee post hoc tests. Results: Pocket Air and APEX PY001 showed the greatest inhaled mass and the lowest dose in the mouthpiece connection. The largest and smallest mass median aerodynamic diameters were found with Omron NE-U22 and PARI VELOX, respectively. In addition, the output rate and inhaled aerosol rate (IAR) of PARI VELOX were higher than those of other nebulizers. Conclusions: This study showed that the performance of commercially available mesh nebulizers varied. Aerosol particles deposited on different auxiliary equipment directly influenced the output rate and IAR of the mesh nebulizer. Clinical validation of the drug IAR is necessary to avoid overdose and reduce drug wastage.