DETERMINATION OF PHENYTION,PHENOBARBITONE AND CARBAMAZEPINE CONCENTRATION IN SERUM BY HPLC

OBJECTIVE:To establish a method for rapid determination of phenytoin, phenobarbitone and carbamazepine in blood serum.METHODS:Using HPLC with barbitone as internal standard, the separation was performed on Kromasil C 18 column with methanol water (57∶43) as mobile phase. The flow rate was 0.8 ml·min 1 . The wavelength for detection was 254 nm.RESULTS:The linear range of phenytoin was 4.0 50 μg·ml 1 ( r =0.9995), phenobarbitone was 5.0 60 μg·ml 1 ( r =0.9996), carbamazepine was 2.5 20 μg·ml 1 ( r =0.9992), the lowest limit of detection was 1.0 μg·ml 1 , 2.0 μg·ml 1 and 0.5 μg·ml 1 . The average recoveries for phenytoin, phenobarbitone and carbamazepine were 99.22%,99.68%and 98.62%,respectively The within day and day to day RSD for 3 compounds were smaller than 5%( n =5).CONCLUSION:This method is accurate, with high sensitivity and good repeatability. It can be used as a routine method for TDM.