title: Relative bioavailability of an extemporaneous ondansetron 4-mg capsule formulation versus solution.
abstract: OBJECTIVE
  To compare the relative bioavailability of an extemporaneous ondansetron capsule formulation with that of an identical dose of the commercially available solution formulation.
  
  
  METHODS
  Open-label, randomized, two-way crossover study.
  
  
  METHODS
  University-affiliated research laboratory.
  
  
  METHODS
  Sixteen (eight men, eight women) healthy, nonsmoking volunteers.
  
  
  METHODS
  Participants were randomly assigned to receive a 4-mg dose of either the commercially available ondansetron solution or the extemporaneous ondansetron capsule formulation. Blood sampling was performed over 12 hours after dosing. After a washout period of at least 3 days, each participant was switched to the alternate formulation, and blood sampling was repeated.
  
  
  RESULTS
  Ondansetron was well absorbed after administration of both formulations, with the solution achieving a faster rate of drug absorption over the first hour of dosing. After the peak plasma concentration was achieved, the plasma concentration-time curves of both formulations declined at a similar steady rate. There were no significant differences in pharmacokinetic parameters between the two formulations, and the relative bioavailability of the capsule versus the solution formulation was 101%.
  
  
  CONCLUSIONS
  Similar concentration-time curves and pharmacokinetic parameters were achieved with the two formulations. The commercially available solution would be a useful alternative formulation for administration of low-dose ondansetron in research and clinical settings.
authors.affiliation: Department of Pharmacology, University of Texas Health Science Center, San Antonio, Texas 78229-3900, USA.
authors.forename: Y W Francis
authors.initials: YW
authors.lastname: Lam
authors.forename: Martin A
authors.initials: MA
authors.lastname: Javors
authors.forename: Nassima
authors.initials: N
authors.lastname: Ait-Daoud
authors.forename: John D
authors.initials: JD
authors.lastname: Roache
authors.forename: Bankole A
authors.initials: BA
authors.lastname: Johnson
mesh_terms: D000328:Adult; D000932:Antiemetics / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D019540:Area Under Curve; D001682:Biological Availability; D002214:Capsules; D018592:Cross-Over Studies; D005260:Female; D005780:Gelatin; D006207:Half-Life; D006801:Humans; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D017294:Ondansetron / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D019999:Pharmaceutical Solutions
chemical_list: D000932:Antiemetics; D002214:Capsules; D019999:Pharmaceutical Solutions; D017294:Ondansetron; D005780:Gelatin