Rapid determination of three antiepileptic drugs in serum by high performance liquid chromatography with solid phase extraction method

OBJECTIVE To establish a rapid analytical method for the determination of phenobarbital(PB),phenytoin(DPH),carbamazepine(CBZ) in serum by high performance liquid chromatography with solid phase extraction method. METHODS Drugs in serum was extracted with a ccubond SPE C 18 column. The analytical column was Nova-pak C 18 column ( 3.9 mm×150 mm,4 μm). The mobile phase consisted of 0.01 mol·L -1 phosphate buffer solution (pH 3.5):methanol(50∶50).The detective wavelength was 210 nm and the flow rate was 1 mL·min -1, column temperature was 25℃. RESULTS Three drugs were extracted completely, impurities were removed. Three drugs were separated well under the chromatographic condition. The linear range of PB,DPH and CBZ were 5～40、5～40 and 2.5～20 mg·L -1, respectively. The relative recoveries of PB,DPH and CBZ were 100.0%, 99.9% and 100.2%, respectively. The relative standard deviation(RSD) of within day and between day were all less than 5.01%. The method has been used for monitoring serum drug concentration of 55 epileptic patients, the results were compared with liquid-liquid extraction method and there was no difference(P 0.05). CONCLUSION This method is found to be rapid(less than 5 min),simple,accurate, sensitive and more suitable for clinical practical application.