High-performance liquid chromatographic analysis of vigabatrin enantiomers in human serum by precolumn derivatization with o-phthaldialdehyde-N-acetyl-L-cysteine and fluorescence detection.
A rapid and simple method is presented for the determination of vigabatrin enantiomers in human serum by high-performance liquid chromatography. Serum is deproteinized with trichloroacetic acid and aliquots of the supernatant are precolumn derivatized with o-phthaldialdehyde and N-acetyl-L-cysteine, resulting in the formation of diastereomeric isoindoles. Separation was achieved on a Spherisorb 3ODS2 column using a gradient solvent program and the column eluent is monitored using fluorescence detection. L-Homoarginine was used as an internal standard. Within-day precisions (C.V.; n=8) were 2.8 and 1.1%, respectively, for the (R)-(-)- and (S)-(+)-enantiomer in serum containing 15.4 mg/l (RS)-vigabatrin. The method was linear in the 0-45 mg/l range for both enantiomers and the minimum quantitation limit was 0.20 mg/l for (R)-(-)-vigabatrin and 0.14 mg/l for (S)-(+)-vigabatrin. No interferences were found from commonly co-administered antiepileptic drugs and from endogenous amino acids. The method is suitable for routine therapeutic drug monitoring and for pharmacokinetic studies.
Vermeij
T A
TA
Laboratory of Clinical Chemistry and Clinical Pharmacology, Instituut voor Epilepsiebestrijding, Heemstede, The Netherlands.
Edelbroek
P M
PM
D000111:Acetylcysteine; D000293:Adolescent; D000328:Adult; D000927:Anticonvulsants / Q000097:blood*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004827:Epilepsy / Q000097:blood / Q000188:drug therapy*; D005260:Female; D006801:Humans; D007202:Indicators and Reagents; D008297:Male; D008875:Middle Aged; D011786:Quality Control; D012680:Sensitivity and Specificity; D013237:Stereoisomerism; D020888:Vigabatrin; D005680:gamma-Aminobutyric Acid / Q000031:analogs & derivatives* / Q000097:blood / Q000737:chemistry; D009764:o-Phthalaldehyde
D000927:Anticonvulsants; D007202:Indicators and Reagents; D005680:gamma-Aminobutyric Acid; D009764:o-Phthalaldehyde; D020888:Vigabatrin; D000111:Acetylcysteine