title: Inspiratory flows and volumes in subjects with cystic fibrosis using a new dry powder inhaler device.
abstract: BACKGROUND
  Drug inhalation via a dry-powder inhaler (DPI) is a convenient, time efficient alternative to nebulizers in the treatment of cystic fibrosis (CF). Efficient drug administration via DPIs depends on the device resistance and adequate (≥ 45L/min) inspiratory flows and volumes generated by individuals. Dry-powder mannitol is delivered using a RS01 breath-actuated device developed by Plastiape, for Pharmaxis. The study aim was to determine in vivo if CF patients' inspiratory flows and volumes are adequate to use the RS01 DPI device.
  
  
  METHODS
  An open, non-interventional study; enrolled 25 CF subjects, aged ≥ 6 years with FEV1 ≥ 30 to < 90‰ predicted. Inspiratory flows and volumes were measured when subjects inhaled in a controlled manner through the RS01 device in series with a spirometer.
  
  
  RESULTS
  The mean inspiratory volume (IV) of CF subjects was 1.83L ± 0.97. Their achieved mean ± SD peak inspiratory flow (PIF) was 75.5 ± 27.2L/min. Twenty-three subjects (92%) achieved PIF of > 45L/min with the inhaler device; eighteen of those subjects (78%) had a baseline FEV1 of > 1L.
  
  
  CONCLUSIONS
  Use of the RS01 DPI device allowed adequate inspiratory flow and volume for dispersion of dry-powder mannitol in CF patients.
authors.affiliation: Royal Prince Alfred Hospital, Sydney, Australia.
authors.forename: Mark R
authors.initials: MR
authors.lastname: Elkins
authors.affiliation: Murdock Children's Research Institute and University of Melbourne, Royal Children's Hospital, Melbourne, Australia.
authors.forename: Philip
authors.initials: P
authors.lastname: Robinson
authors.affiliation: Royal Prince Alfred Hospital, Sydney, Australia.
authors.forename: Sandra D
authors.initials: SD
authors.lastname: Anderson
authors.affiliation: Royal Prince Alfred Hospital, Sydney, Australia.
authors.forename: Clare P
authors.initials: CP
authors.lastname: Perry
authors.affiliation: Royal Prince Alfred Hospital, Sydney, Australia.
authors.forename: Evangelia
authors.initials: E
authors.lastname: Daviskas
authors.affiliation: Pharmaxis Ltd, Sydney, Australia.
authors.forename: Brett
authors.initials: B
authors.lastname: Charlton
keywords: Clinical trials; cystic fibrosis; dry powder inhaler; high resistance inhaler; peak inspiratory flow.; respiratory function tests