Stereoselective determination of vigabatrin enantiomers in human plasma by high performance liquid chromatography using UV detection.
A rapid and simple high-performance liquid chromatographic method for the determination of the R-(-)- and S-(+)-enantiomers of the antiepileptic drug vigabatrin in human plasma is described. After adding the internal standard (1-aminomethyl-cycloheptyl-acetic acid), plasma samples (200 microL) are deproteinized with acetonitrile and the supernatant is derivatized with 2,4,6 trinitrobenzene sulfonic acid (TNBSA). Separation is achieved on a reversed-phase cellulose-based chiral column (Chiralcel-ODR, 250 mm x 4.6 mm i.d.) using 0.05 M potassium hexafluorophosphate (pH 4.5)/acetonitrile/ethanol (50:40:10 vol/vol/vol) as mobile phase at a flow-rate of 0.9 mL/min. Chromatographic selectivity is improved by concentrating the derivatives on High Performance Extraction Disk Cartridges prior to injection. Detection is at 340 nm. Calibration curves are linear (r(2)> or =0.999) over the range of 0.5-40 microg/mL for each enantiomer, with a limit of quantification of 0.5 microg/mL for both analytes. The assay is suitable for therapeutic drug monitoring and for single-dose pharmacokinetic studies in man.
Franco
Valentina
V
Clinical Pharmacology Unit, Department of Internal Medicine and Therapeutics, University of Pavia, Pavia, Italy.
Mazzucchelli
Iolanda
I
Fattore
Cinzia
C
Marchiselli
Roberto
R
Gatti
Giuliana
G
Perucca
Emilio
E
D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D012015:Reference Standards; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*; D013237:Stereoisomerism; D020888:Vigabatrin / Q000097:blood*
D020888:Vigabatrin