title: Pharmacokinetics of beclomethasone dipropionate in an hydrofluoroalkane-134a propellant system in Japanese children with bronchial asthma.
abstract: BACKGROUND
  Hydrofluoroalkane-134a (HFA) has been shown to be a safe replacement for chlorofluorocarbons (CFCs) as a pharmaceutical propellant, with the advantage that it has no ozone-depleting potential. This is the first report of the pharmacokinetics of beclomethasone dipropionate (BDP) delivered from a pressurized solution formulation using an HFA propellant system (HFA-BDP) in Japanese children with bronchial asthma.
  
  
  METHODS
  Plasma concentrations of beclomethasone 17-monopropionate (17-BMP),a major metabolite of BDP, following an inhaled dose of HFA-BDP (200 microg as four inhalations from 50 microg/actuation) in five Japanese children with bronchial asthma were quantified and analyzed by a non-compartmental analysis to obtain pharmacokinetic parameters.
  
  
  RESULTS
  The area under the concentration-time curve from time zero to the last quantifiable time (AUC(0-t)) was 1659 +/- 850 pg x h/mL (arithmetic mean +/- standard deviation (SD)), the maximum concentration observed (C(max)) was 825 +/- 453 pg/mL and the apparent elimination half-life (t(1/2)) was 2.1 +/- 0.7 hours. The time to reach Cmax Tmax was 0.5 hours in all patients. No special relationship was observed between these parameters and age or body weight. These parameters were compared with the previously reported parameters of American children with bronchial asthma. The Japanese/American ratio of the geometric means of each parameter was 1.36 for AUC(0-t), 1.04 for Cmax and 1.4 for t(1/2). The median of Tmax was 0.5 hours in American patients as well as Japanese patients.
  
  
  CONCLUSIONS
  The pharmacokinetics of HFA-BDP in Japanese children with bronchial asthma are reported for the first time and a similarity to those in American children is suggested.
authors.affiliation: Department of Pediatrics, Graduate School of Medicine, Gifu University, 1-1 Yanagido, Gifu, Japan. t-tera@cc.gifu-u.ac.jp
authors.forename: Takahide
authors.initials: T
authors.lastname: Teramoto
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Fukao
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Tomita
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Terauchi
authors.forename: Kaori
authors.initials: K
authors.lastname: Hosoi
authors.forename: Eiko
authors.initials: E
authors.lastname: Matsui
authors.forename: Minako
authors.initials: M
authors.lastname: Aoki
authors.forename: Naomi
authors.initials: N
authors.lastname: Kondo
authors.forename: Haruki
authors.initials: H
authors.lastname: Mikawa
mesh_terms: D000293:Adolescent; D000335:Aerosol Propellants; D018927:Anti-Asthmatic Agents / Q000493:pharmacokinetics*; D001249:Asthma / Q000188:drug therapy*; D001507:Beclomethasone / Q000493:pharmacokinetics*; D002648:Child; D005260:Female; D006801:Humans; D006845:Hydrocarbons, Fluorinated; D007564:Japan; D008297:Male; D014481:United States; D005466:Fluorocarbons
chemical_list: D000335:Aerosol Propellants; D018927:Anti-Asthmatic Agents; D001507:Beclomethasone; D006845:Hydrocarbons, Fluorinated; C094049:apaflurane; D005466:Fluorocarbons