title: Bioequivalence of fexofenadine tablet formulations assessed in healthy Iranian volunteers.
abstract: OBJECTIVE
  Many drug products containing the same amount of active drug are made and marketed by more than one pharmaceutics manufacturer. Since the quality of final drug product is affected by the source of ingredients, type and amount of excipients and manufacturing process, bioequivalence studies are used to determine the bioavailability and characterize the pharmacokinetics of the new formulation relative to a reference formulation. In the present study the bioavailability of a new capsule formulation of fexofenadine (CAS 153439-40-8) was compared to a reference formulation in 12 healthy male volunteers.
  
  
  METHODS
  The blood samples were collected at different time points. After centrifugation and decanting the plasma, the drug was extracted using a mixture of diethyl ether/isopropyl alcohol (5:95% v/v). Then the samples were dried at 45 degrees C under nitrogen and finally, after dissolving the dried sample in mobile phase, the plasma drug concentrations were determined using HPLC. The pharmacokinetic parameters (Cmax, AUCt0, AUCinfinity0) were statistically compared by analysis of variance (ANOVA) for test and reference formulations and no statistical differences were observed.
  
  
  CONCLUSIONS
  The maximum plasma concentration (Cmax) of fexofenadine was 1206.3 +/- 619.0 ng/ml for the test and 1172.6 +/- 493.7 ng/ml for the reference formulation. The mean AUC0-infinity of fexofenadine was 8911.4 +/- 3870.0 and 9363.9 +/- 2668.0 ng x h/ml for the test and reference formulation, respectively. The calculated 90% confidence intervals for the mean test/reference ratios of mentioned parameters were 90.0-113.9, 86.9-109.5 and 80.8-102.8, respectively, which are in the bioequivalence range.
  
  
  CONCLUSIONS
  Based on the obtained results the two fexofenadine formulations are considered to be equivalent.
authors.affiliation: Department of Pharmaceutics, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Hadi
authors.initials: H
authors.lastname: Valizadeh
authors.forename: Leila
authors.initials: L
authors.lastname: Barghi
authors.forename: Hadi
authors.initials: H
authors.lastname: Jalilian
authors.forename: Ziba
authors.initials: Z
authors.lastname: Islambulchilar
authors.forename: Parvin
authors.initials: P
authors.lastname: Zakeri-Milani
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D018926:Anti-Allergic Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D019540:Area Under Curve; D002626:Chemistry, Pharmaceutical; D002851:Chromatography, High Pressure Liquid; D018592:Cross-Over Studies; D006801:Humans; D007492:Iran; D008297:Male; D016037:Single-Blind Method; D013607:Tablets; D016593:Terfenadine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D013810:Therapeutic Equivalency; D055815:Young Adult
chemical_list: D018926:Anti-Allergic Agents; D013607:Tablets; D016593:Terfenadine; C093230:fexofenadine