Comparative bioavailability of 4 amoxicillin formulations in healthy human volunteers after a single dose administration.
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.
Oliveira
C H
CH
Department of Pharmacology, São Paulo, Brazil.
Abib
E
E
Vannuchi
Y B
YB
Sucupira
M
M
Ilha
J
J
De Nucci
G
G
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*
D002214:Capsules; D010406:Penicillins; D000658:Amoxicillin