Simple and rapid HPLC method for simultaneous determination of multiple antiepileptic drugs in human serum

Avery rapid, sensitive and reproducible HPLC method was developed for simul taneous determination of eight anti-epileptic drugs (AEDs): lamotrigine, pr imidone, ethosuximide, sulthiame, felbamate, phenobarbital, carbamazepine, phenytoin and oxcarbazepine-metabolite (10-hydroxy-carbazepine) in human se rum. Sample purification requires only protein precipitation with an approp riate reagent. Separation was by reversed-phase HPLC, using a C18 column, 2 0% acetonitrile and 40 mM phosphoric acid buffer as mobile phase. Column te mperature was set at 50 degreesC, and measurement was by UV detection at 20 5 nm. The inter and intra-assay coefficients of variation (CV) ranged 1.13- 710% and 1.14-8.49%, respectively. The absolute (measured) and relative (an alytic) recoveries of the drugs ranged 96.7%-104.4% and 97.3%-106.1%, respe ctively. No interference with other common antiepileptic drugs and analgesi cs were observed. The method requires only 100 muL serum or less. it is ver y fast (sample preparation and analysis time approx 23 min for all 9 AEDs), and suitable for routine clinical use, especially for epileptic patients o n polytherapy.