Simultaneous determination of concentration of 5 kinds of antiepileptic in human serum by HPLC

Objective To develop a new method for simultaneously determining Lamotrigine, phenobarbital, phenytoin, carbamazepine and clonazepam in human serum by HPLC. Methods Serum samples were analyzed after protein deposition by methanol.The HPLC method was performed on the column of Waters C18(5μm, 4.6×250mm) with mobile phase consisted of ethanol-water(55 ∶ 45), the UV detection wavelength was 235 nm. Results In a certain range of concentration(lamotrigine: 1.3-50.0μg/m L; phenobarbital: 2.5-100.0μg/m L; phenyltoin: 2.2-70.0μg/m L; carbamazepine: 1.8-35.0μg/m L; clonazepam: 2.5-80.0μg/m L), there was a good linear relationship between peak area and concentration of each drug. Low、medium and high concentration of the quality control sample recovery rate was higher than 95%, the relative standard deviation(RSD) is less than 10%. Conclusion The method provides a sensitive, accurate, precise and reliable analytical procedure for clinical monitoring of 5 compounds which is suitable for therapeutic drug monitoring.