title: Pharmacokinetics of budesonide and formoterol administered via a series of single-drug and combination inhalers: four open-label, randomized, crossover studies in healthy adults.
abstract: OBJECTIVE
  To investigate the pharmacokinetics of budesonide and formoterol administered concomitantly in healthy adults.
  
  
  METHODS
  Three single-dose, open-label crossover studies (n=28 each) were conducted (Study I: budesonide pMDI, formoterol DPI, budesonide pMDI+formoterol DPI; Study II: budesonide/formoterol pMDI, budesonide pMDI+formoterol DPI; Study III: budesonide/formoterol pMDI [three budesonide formulation strengths; constant formoterol]). Study IV (n=28) assessed steady state pharmacokinetics (budesonide/formoterol pMDI [two/four inhalations twice daily, 5-day treatment; four inhalations, single-dose]).
  
  
  RESULTS
  Study I: no pharmacokinetic interactions were observed between budesonide and formoterol. Study II: AUC ratios were 97.9% (budesonide) and 82.2% (formoterol) (budesonide/formoterol pMDI versus budesonide pMDI+formoterol DPI). Study III: formoterol AUC was comparable across budesonide/formoterol pMDI formulation strengths; budesonide AUC increased with formulation strength in proportion to fine particle dose. Study IV: dose proportionality was demonstrated for budesonide (AUC ratio, 104.3%) and suggested for formoterol (AUC ratio, 117.6%) with budesonide/formoterol pMDI (steady state); budesonide and formoterol AUC was higher with repeated versus single-dose budesonide/formoterol pMDI (four inhalations).
  
  
  CONCLUSIONS
  No pharmacokinetic interactions were observed between budesonide and formoterol. Budesonide dose variation in budesonide/formoterol pMDI did not affect formoterol exposure. Steady state budesonide/formoterol pMDI dose-doubling yielded proportional increases in budesonide and formoterol exposure.
authors.affiliation: AstraZeneca, Lund, Sweden.
authors.forename: Annika
authors.initials: A
authors.lastname: Eklund
authors.forename: Ann
authors.initials: A
authors.lastname: Tronde
authors.forename: Ingegerd
authors.initials: I
authors.lastname: Johannes-Hellberg
authors.forename: Michael
authors.initials: M
authors.lastname: Gillen
authors.forename: Lars
authors.initials: L
authors.lastname: Borgström
mesh_terms: D000328:Adult; D019540:Area Under Curve; D001993:Bronchodilator Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D019819:Budesonide / Q000008:administration & dosage / Q000493:pharmacokinetics*; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D004347:Drug Interactions; D004359:Drug Therapy, Combination; D004983:Ethanolamines / Q000008:administration & dosage / Q000493:pharmacokinetics*; D005260:Female; D000068759:Formoterol Fumarate; D006801:Humans; D036501:Metered Dose Inhalers; D008875:Middle Aged; D009330:Nebulizers and Vaporizers; D010316:Particle Size
chemical_list: D001993:Bronchodilator Agents; D004338:Drug Combinations; D004983:Ethanolamines; D019819:Budesonide; D000068759:Formoterol Fumarate