title: The effect of altitude on inhaler performance.
abstract: The purpose of the study is to understand the effect of altitude on the performance of selected pressurized metered dose inhalers (pMDIs) and dry powder inhalers (DPIs). A testing apparatus that created consistent breath profiles through the Alberta Idealized Throat was designed to test five pMDIs and two DPIs at altitudes of 670, 2450, 3260, and 4300 m. Both gravimetric and chemical assays were conducted to determine the in vitro lung dose. Additionally, spray duration and shot weight for pMDIs and device resistance for DPI were measured. There was no significant change in in vitro lung dose for any of the pMDIs tested. Shot weight and spray duration were unaffected. The device resistance of the DPIs decreased with increasing altitude and was successfully modeled as a function of ambient pressure. The in vitro lung dose of both DPIs showed no significant change when operated with an inhaler pressure drop of 4 kPa, but for the Bricanyl(®) Turbuhaler(®), a significant decrease occurred when matching the volumetric inspiratory flow rate to that of the baseline altitude.
authors.affiliation: Department of Mechanical Engineering, University of Alberta, Edmonton, AlbertaT6G 2T8, Canada.
authors.forename: Jordan T F
authors.initials: JTF
authors.lastname: Titosky
authors.affiliation: Department of Mechanical Engineering, University of Alberta, Edmonton, AlbertaT6G 2T8, Canada.
authors.forename: Chelsea M D
authors.initials: CMD
authors.lastname: Morin
authors.affiliation: Department of Mechanical Engineering, University of Alberta, Edmonton, AlbertaT6G 2T8, Canada.
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Suderman
authors.affiliation: Department of Mechanical Engineering, University of Alberta, Edmonton, AlbertaT6G 2T8, Canada.
authors.forename: Jason S
authors.initials: JS
authors.lastname: Olfert
authors.affiliation: Department of Mechanical Engineering, University of Alberta, Edmonton, AlbertaT6G 2T8, Canada.
authors.forename: Warren H
authors.initials: WH
authors.lastname: Finlay
authors.affiliation: Department of Mechanical Engineering, University of Alberta, Edmonton, AlbertaT6G 2T8, Canada. Electronic address: reinhard.vehring@ualberta.ca.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Vehring
mesh_terms: D000336:Aerosols; D000531:Altitude; D001249:Asthma / Q000188:drug therapy; D001993:Bronchodilator Agents / Q000008:administration & dosage; D058995:Dry Powder Inhalers / Q000592:standards*; D004867:Equipment Design; D006801:Humans; D008422:Materials Testing; D036501:Metered Dose Inhalers / Q000592:standards*; D008954:Models, Biological
chemical_list: D000336:Aerosols; D001993:Bronchodilator Agents
keywords: aerosols; dry powder inhaler; high altitude; inhaler performance; patient use; pressurized metered dose inhaler; pulmonary; pulmonary drug delivery