title: Pharmaceutical aerosols deposition patterns from a Dry Powder Inhaler: Euler Lagrangian prediction and validation.
abstract: This study uses Computational Fluid Dynamics (CFD) to predict, analyze and validate the deposition patterns in a human lung for a Budesonide drug delivered from the Novolizer Dry Powder Inhaler device. We used a test case of known deposition patterns to validate our computational Euler Lagrangian-based deposition predictions. Two different lung models are used: (i) a basic ring-less trachea model and (ii) an advanced Human Zygote5 model. Unlike earlier attempts, the current simulations do not include the device in the computational domain. This greatly reduces the computational effort. To mimic the device, we model the inlet particle jet stream from the device as a spray entering the mouth in a conical fashion. Deposition studies in the various lung regions were performed. We were able to computationally predict and then demonstrate the enhanced deposition in the tracheal and first generation rings/ridges. The enhanced vorticity creation due to the ring structure and the geometrical design contributes to larger deposition in the Zygote5 model. These are in accord with existing data, unlike the ring-less model. Our validated results indicate the need to (i) introduce the ridges in the experimental casts and the CFD surface meshes to be anatomically consistent and obtain physiologically consistent depositions; (ii) introduce a factor to account for the recirculating lighter particles in empirical models.
authors.affiliation: CFD Research Corporation, 701 McMillian Way NW, Suite D, Huntsville, AL 35806, USA. Electronic address: ravi.kannan@cfdrc.com.
authors.forename: Ravishekar
authors.initials: R
authors.lastname: Ravi Kannan
authors.affiliation: CFD Research Corporation, 701 McMillian Way NW, Suite D, Huntsville, AL 35806, USA.
authors.forename: A J
authors.initials: AJ
authors.lastname: Przekwas
authors.affiliation: CFD Research Corporation, 701 McMillian Way NW, Suite D, Huntsville, AL 35806, USA.
authors.forename: Narender
authors.initials: N
authors.lastname: Singh
authors.affiliation: Center for Drug Evaluation Research, United States Food and Drug Administration, Silver Spring, Maryland, USA.
authors.forename: Renishkumar
authors.initials: R
authors.lastname: Delvadia
authors.affiliation: Center for Drug Evaluation Research, United States Food and Drug Administration, Silver Spring, Maryland, USA.
authors.forename: Geng
authors.initials: G
authors.lastname: Tian
authors.affiliation: Center for Drug Evaluation Research, United States Food and Drug Administration, Silver Spring, Maryland, USA.
authors.forename: Ross
authors.initials: R
authors.lastname: Walenga
mesh_terms: D000336:Aerosols; D003198:Computer Simulation; D058995:Dry Powder Inhalers; D057446:Hydrodynamics; D004364:Pharmaceutical Preparations / Q000008:administration & dosage*; D015203:Reproducibility of Results
chemical_list: D000336:Aerosols; D004364:Pharmaceutical Preparations
keywords: Cartilaginous rings; Computational fluid dynamics; Deposition; Novolizer; Vorticity