Functional similarity of modified cascade impactor to deposit drug particles on cells

Pulmonary drug delivery is a non-invasive and effective route for local or systemic drug administration. Despite several products in the market, the mechanism of drug absorption from the lungs is not well understood. An in vitro model for aerosol deposition and transport across epithelia that uses particle deposition may be a good predictor of and help understand in vivo drug disposition. The objective of this study was to examine the uptake of HFA fluticasone (Flovent HFA) particles at various stages of the Next Generation Impactor (NGI) by human Calu-3 cell line derived from human bronchial respiratory epithelial cell monolayer. Particles were directly deposited on Calu-3 cells incorporated onto stages 3, 5, and 7 of the NGI at the air-liquid interface (ALI). We modified the NGI apparatus to allow particle deposition directly on cells and determined the in vitro deposition characteristics using modified NGI. Particles of different size ranges showed different in vitro epithelial transport rates. This study highlights the need to develop in vitro test systems to determine the deposition of aerosol particles on cell monolayers by simultaneously considering aerodynamic properties.