title: Influence of peak inspiratory flow rates and pressure drops on inhalation performance of dry powder inhalers.
abstract: The aim of this study was to reveal the relationship between human inspiratory flow patterns and the concomitant drops in pressure in different inhalation devices, and the influence of the devices on inhalation performance. As a model formulation for inhalers, a physically mixed dry powder composed of salbutamol sulfate and coarse lactose monohydrate was selected. The drops in pressure at 28.3 L/min of three inhalation devices, Single-type, Dual-type, and Reverse-type, was 1.0, 5.1, and 8.7 kPa, respectively. Measurements of human inspiratory patterns revealed that although the least resistant device (Single) had large inter- and intra-individual variation of peak flow rate (PFR), the coefficients of variation of PFR of the three devices were almost the same. In tests with a human inspiratory flow simulator in vitro, inhalation performance was higher, but the variation in inhalation performance in the range of human flow patterns was wider, for the more resistant device. To minimize the intra- and inter-individual variation in inhalation performance for the model formulation in this study, a formulation design that allows active pharmaceutical ingredient to detach from the carrier with a lower inhalation flow rate is needed.
authors.affiliation: Faculty of Pharmacy, Meijo University, Nagoya, Japan.
authors.forename: Daiki
authors.initials: D
authors.lastname: Hira
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Okuda
authors.forename: Mika
authors.initials: M
authors.lastname: Ichihashi
authors.forename: Ayano
authors.initials: A
authors.lastname: Mizutani
authors.forename: Kazunori
authors.initials: K
authors.lastname: Ishizeki
authors.forename: Toyoko
authors.initials: T
authors.lastname: Okada
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Okamoto
mesh_terms: D000280:Administration, Inhalation; D000328:Adult; D000420:Albuterol / Q000008:administration & dosage / Q000737:chemistry; D001993:Bronchodilator Agents / Q000008:administration & dosage / Q000737:chemistry; D002626:Chemistry, Pharmaceutical / Q000379:methods; D058995:Dry Powder Inhalers / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D005260:Female; D006801:Humans; D001239:Inhalation / Q000502:physiology*; D007785:Lactose / Q000008:administration & dosage / Q000737:chemistry; D008297:Male; D010316:Particle Size; D011208:Powders / Q000008:administration & dosage / Q000737:chemistry*; D011312:Pressure; D055815:Young Adult
chemical_list: D001993:Bronchodilator Agents; D011208:Powders; D007785:Lactose; D000420:Albuterol