RESUMO
OBJECTIVE: To establish a RP - HPLC method for simultaneous determination of the concentrations of phe-nobarbital, phenytoin and carbamazepine in serum.METHODS: Phenobarbital, phenytoin and carbamazepine were extracted from serum with CH2Cl2 and analysed using C18 column with mobile phase consisting of methanol - water(57 : 43); the column temperature was 30℃ ; the detecting wavelength was 254nm and the flow rate was 0.8ml/ min.RESULTS: The calibrating curves of phanobarbital, phenytoin and carbamazepine were linear in the ranges of 2.5 - 40, 2.5-40 and 1.25-20?g/ ml respectively .The within- day and between- day RSDs were less than 10% (n = 5) .CONCLUSION : This method is simple and reliable and suitable for phenobarbital,phanytoin and carbamazepine monitoring.