title: Comparative bioavailability of 4 amoxicillin formulations in healthy human volunteers after a single dose administration.
abstract: OBJECTIVE
  To compare the bioavailability of two amoxicillin oral suspension (250 mg/5 ml) formulations and two amoxicillin capsule (500 mg) formulations (Amoxicilina from Medley S/A Indústria Farmaceûtica, Brazil, as test formulations and Amoxil from SmithKline Beecham Laboratórios Ltda., Brazil, as reference formulations) in 48 volunteers of both sexes.
  
  
  METHODS
  The study was conducted open with a randomized two-period crossover design and a one-week washout period. Plasma samples were obtained over a 12-hour interval. Amoxicillin concentrations were analyzed by combined reversed phase liquid chromatography and tandem mass spectrometry (LC-MS-MS) with positive ion electrospray ionization using the selected ion monitoring method. From the amoxicillin plasma concentration vs. time curves the following pharmacokinetic parameters were obtained: AUC(last), AUC(0-infinity) and Cmax.
  
  
  RESULTS
  Geometric mean of Amoxicilina/Amoxil 250 mg/5 ml individual percent ratio was 103.70% for AUC(last), 103.15% for AUC(0-infinity) and 106.79% for Cmax. The 90% confidence intervals were 97.82-109.94%, 97.40 to 109.24%, and 96.38-118.33%, respectively. Geometric mean of Amoxicilina/Amoxil 500 mg capsule individual percent ratio was 93.26% for AUC(last), 93.27% for AUC(0-infinity) and 90.74% for Cmax. The 90% confidence intervals were 85.0-102.33%, 85.12-102.31%, and 80.14-102.73%, respectively.
  
  
  CONCLUSIONS
  Since the 90% CI for both Cmax, AUC(last) and AUC(0-inifnity) were within the 80-125% interval proposed by the Food and Drug Administration, it was concluded that Amoxicilina 250 mg/5 ml oral suspension and Amoxicilina 500 mg capsule were bioequivalent to Amoxil 250 mg/5 ml oral suspension and to Amoxil capsule 500 mg, respectively, with regard to both the rate and extent of absorption.
authors.affiliation: Department of Pharmacology, São Paulo, Brazil.
authors.forename: C H
authors.initials: CH
authors.lastname: Oliveira
authors.forename: E
authors.initials: E
authors.lastname: Abib
authors.forename: Y B
authors.initials: YB
authors.lastname: Vannuchi
authors.forename: M
authors.initials: M
authors.lastname: Sucupira
authors.forename: J
authors.initials: J
authors.lastname: Ilha
authors.forename: G
authors.initials: G
authors.lastname: De Nucci
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000658:Amoxicillin / Q000097:blood / Q000493:pharmacokinetics*; D001682:Biological Availability; D002214:Capsules; D002626:Chemistry, Pharmaceutical; D002853:Chromatography, Liquid; D018592:Cross-Over Studies; D005260:Female; D006207:Half-Life; D006801:Humans; D008297:Male; D008875:Middle Aged; D010406:Penicillins / Q000097:blood / Q000493:pharmacokinetics*
chemical_list: D002214:Capsules; D010406:Penicillins; D000658:Amoxicillin