Rapid determination of three antiepileptic drugs in serum by reversed phase high performance liquid chromatography

OBJECTIVE To establish a rapid analytical method for the determination of phenobartial(PB),phenytoin(DPH) and carbamazepine(CBZ) in serum by reversed phase high performance liquid chromatography(RP-HPLC). METHOD Ethyl acetate was selected as extract solvent. The analytical column was Nova-Pak C 18 column (3.9mm×150mm,4μm).The mobile phase consisted of 0.01mol/L phosphate buffer solution (pH3.5):methanol(50∶50).The detection wavelength was 210nm and the flow rate was 1mL/min. RESULTS Three drugs were separated well under the chromatographic condition. The linear range of PB,DPH and CBZ were 1-100,1-40 and 1-20μg·mL -1, respectively. The relative recoveries of PB,DPH and CBZ were 99.8%,99.6% and 100.6%, respectively. The relative standard deviation(RSD) of within day and between day were all less than 6%. The method has been used for monitoring serum drug concentration of 229 epileptic patients, 56.1% of the patients who had taken DPH was found the serum concentration lower than effective level and 21.0% of these patients was found higher than effective level. CONCLUSION This method is rapid(less than 5 min),accurate, sensitive and more suitable for clinical application.