Determination of gabapentin in plasma by high-performance liquid chromatography.
A rapid and simple method for determination of the novel antiepileptic compound gabapentin [1-(aminomethyl)cyclohexaneacetic acid] in plasma is described. Blank human plasma was spiked with gabapentin (1.0-10.0 micrograms/ml) and internal standard [1-(aminomethyl)-cycloheptaneacetic acid; 5.0 micrograms/ml]. Individual samples were treated with 2 M perchloric acid, centrifuged and then derivatised with o-phthalaldehyde-3-mercaptopropionic acid. Separation was achieved on a Beckman Ultrasphere 5 microns reversed-phase column with mobile phase consisting of 0.33 M acetate buffer (pH 3.7; containing 100 mg/l EDTA)-methanol-acetonitrile (40:30:30, v/v). Eluents were monitored by fluorescence spectroscopy with excitation and emission wavelengths of 330 and 440 nm, respectively. The calibration curve for gabapentin in plasma was linear (r = 0.9997) over the concentration range 1.0-10.0 micrograms/ml. Recovery was seen to be > or = 90%. The inter- and intra-assay variations for three different gabapentin concentrations were < or = 10% throughout. The lower limit of quantitation was found to be 0.5 microgram/ml. Chromatography was unaffected by a range of commonly employed antiepileptic drugs or selected amino acids.
Forrest
G
G
University Department of Medicine and Therapeutics, Western Infirmary, Glasgow, UK.
Sills
G J
GJ
Leach
J P
JP
Brodie
M J
MJ
D000085:Acetates / Q000097:blood*; D000588:Amines; D000596:Amino Acids / Q000097:blood; D000927:Anticonvulsants / Q000097:blood*; D002851:Chromatography, High Pressure Liquid / Q000379:methods* / Q000706:statistics & numerical data; D003509:Cyclohexanecarboxylic Acids; D000077206:Gabapentin; D006801:Humans; D011786:Quality Control; D012680:Sensitivity and Specificity; D005680:gamma-Aminobutyric Acid
D000085:Acetates; D000588:Amines; D000596:Amino Acids; D000927:Anticonvulsants; D003509:Cyclohexanecarboxylic Acids; D005680:gamma-Aminobutyric Acid; D000077206:Gabapentin