The assay of monohydroxy carbamazepine, the active metabolite of oxcarbazepine, in human plasma by HPLC / 药学实践杂志

ABSTRACT

Objective To establish an assay method for monohydroxy carbamazepine, the active metabolite of oxcarbazepine, in human plasma. Methods Ornidazole was used as the internal standard. Plasma samples were processed with methanol and analyzed by HPLC. The column was ZORBAX Eclipse XDB-C18(150 mm×4.6 mm, 5 μm) with the mobile phase of water-acetonitrile (80∶20, V/V) at a flow rate of 1.0 ml/min. Dual wavelength detection is applied. The detection wavelength of monohydroxy carbamazepine was set at 192 nm and ornidazole at 318 nm. Results There was an excellent liner relationship for monohydroxy carbamazepine from 2 to 50 μg/ml(r= 0.998 6). The limit of quantification was 2 μg/ml with the range of accuracy between 95.57% and 100.59%. The RSD of intra-day and inter-day precisions were less than 15%. The average extraction recovery rate of MHC and internal standard were in the range of 89.62% to 98.76%. The RSD of stability was less than 6%. Conclusion This method is specific, sensitive, and easy to operate. It is suitable for the clinical assay of monohydroxy carbamazepine in human plasma.