title: Achiral-chiral LC/LC-FLD coupling for determination of carvedilol in plasma samples for bioequivalence purposes.
abstract: Bioequivalence data for two pharmaceutical formulations (solid oral dosage forms) containing carvedilol is presented for both racemic and enantiomers of the active substance. This was achieved by on-line coupling of two liquid chromatographic separations followed by fluorescence detection. The first LC dimension was used for a fast separation of racemic carvedilol from propranolol (IS) and the endogenous matrix, by means of a reversed phase mechanism. The peak of racemic carvedilol was on-line transferred to the second enantioselective LC dimension, based on a reversed phase separation on cellulose tris(3,5-dimethyl-phenylcarbamate) stationary phase. Both stages were monitored over a single run by means of a fluorescence detector operated at an excitation wavelength of 285 nm and an emission wavelength of 355 nm. Automated shortcutting of the racemic carvedilol peak to the chiral column and simultaneous detection over the two LC dimensions have been obtained by using an experimental set-up based on two six-port rotative switching valves. Linearity was demonstrated on the interval 2-150 ng/mL for racemic carvedilol and on 1-75 ng/mL intervals for enantiomers. LLOQ fits between 0.7 and 1.4 ng/mL. Recoveries of the target compounds are 87+/-4 and 81+/-4% for the IS. Precision ranged from 0.6 to 2.5% and the mean accuracy obtained on quality control samples (measured as % bias) over the whole study falls between -0.8 and 6.3%.
authors.affiliation: University of Bucharest, Faculty of Chemistry, Department of Analytical Chemistry, Sos. Panduri No. 90, Bucharest 050663, Romania. avmedved@yahoo.com
authors.forename: Andrei
authors.initials: A
authors.lastname: Medvedovici
authors.forename: Florin
authors.initials: F
authors.lastname: Albu
authors.forename: Cristina
authors.initials: C
authors.lastname: Georgita
authors.forename: Daniela Iuliana
authors.initials: DI
authors.lastname: Sora
authors.forename: Toma
authors.initials: T
authors.lastname: Galaon
authors.forename: Stefan
authors.initials: S
authors.lastname: Udrescu
authors.forename: Victor
authors.initials: V
authors.lastname: David
mesh_terms: D000293:Adolescent; D000319:Adrenergic beta-Antagonists / Q000097:blood* / Q000493:pharmacokinetics; D000328:Adult; D002138:Calibration; D002227:Carbazoles / Q000097:blood* / Q000493:pharmacokinetics; D000077261:Carvedilol; D002853:Chromatography, Liquid / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D004364:Pharmaceutical Preparations / Q000737:chemistry; D011412:Propanolamines / Q000097:blood* / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013237:Stereoisomerism; D013810:Therapeutic Equivalency
chemical_list: D000319:Adrenergic beta-Antagonists; D002227:Carbazoles; D004364:Pharmaceutical Preparations; D011412:Propanolamines; D000077261:Carvedilol