title: In vitro testing of two formoterol dry powder inhalers at different flow rates.
abstract: The efficiency of two different dry powder inhaler systems for the application of the beta2-sympathomimetic drug Formoterol in the lungs has been tested in vitro. Particle size distributions for each device have been measured at four different flow rates (28.3, 40, 60, and 80 L/min) using an Andersen-Impactor. Mass median aerodynamic diameters (MMAD) of the dispersed powder and deposition of the drug in the respiratory tract was determined using a semiempirical lung deposition model. The optimum output for both devices determined by in vitro measurements is supposed to be achieved with flow rates of 40-60 L/min. The Oxis Turbuhaler delivers the smaller particles as the Foradil P Aerolizer and, thus, the Formoterol deeper into the lungs, but the high specific airflow resistance will influence the ability of patients with severe asthma and children to use the system.
authors.affiliation: InAMed GmbH, Gauting, Germany. weuthen@inamed.de
authors.forename: T
authors.initials: T
authors.lastname: Weuthen
authors.forename: S
authors.initials: S
authors.lastname: Roeder
authors.forename: P
authors.initials: P
authors.lastname: Brand
authors.forename: B
authors.initials: B
authors.lastname: Müllinger
authors.forename: G
authors.initials: G
authors.lastname: Scheuch
mesh_terms: D000318:Adrenergic beta-Agonists / Q000008:administration & dosage*; D000328:Adult; D001249:Asthma / Q000188:drug therapy; D002648:Child; D004983:Ethanolamines / Q000008:administration & dosage*; D000068759:Formoterol Fumarate; D006801:Humans; D066298:In Vitro Techniques; D008168:Lung; D009330:Nebulizers and Vaporizers; D010316:Particle Size; D011208:Powders
chemical_list: D000318:Adrenergic beta-Agonists; D004983:Ethanolamines; D011208:Powders; D000068759:Formoterol Fumarate