Validated HPLC method for the determination of gabapentin in human plasma using pre-column derivatization with 1-fluoro-2,4-dinitrobenzene and its application to a pharmacokinetic study.

A rapid, sensitive and accurate high-performance liquid chromatographic method with UV detection was developed and validated for the quantification of gabapentin in human plasma. Gabapentin was quantified using pre-column derivatization with 1-fluoro-2,4-dinitrobenzene following protein precipitation of plasma with acetonitrile. Amlodipine was used as internal standard. The chromatographic separation was carried out on a Nova-Pak C(18) column using a mixture of 50 mM NaH(2)PO(4) (pH=2.5)-acetonitrile (30:70, v/v) as mobile phase with UV detection at 360 nm. The flow rate was set at 1.5 ml/min. The method was linear over the range of 0.05-5 microg/ml of gabapentin in plasma (r(2)>0.999). The within-day and between-day precision values were in the range of 2-5%. The limit of quantification of the method was 0.05 microg/ml. The method was successfully used to study the pharmacokinetics of gabapentin in healthy volunteers.