A rapid and simple RP-HPLC method for quantification of desipramine in human plasma

Abstract

A high-performance liquid chromatographic (HPLC) method for the determination of antidepressant drug desipramine as active metabolite of imipramine in plasma is reported. The method is based on the purple chromogen formed by displacement reaction of desipramine with 7,7,8,8-tetracyanoquinodimethane in acetonitrile at 80 degrees C for 20 min. The assay is based on liquid-liquid extraction with chloroform and reversed-phase chromatography with UV-visible detection. Liquid chromatography was performed on a Luna C(18) column (250 mm x 4.6 mm, 5 mu m) with a mobile phase acetonitrile/water (70: 30) at a flow rate of 1.0 ml/min. Paroxetine was used as internal standard. The retention time was 15.5 and 13.1 min for desipramine and paroxetine. The detector was operated at 567 nm. The method was linear in the range of 15-400 ng/ml with a correlation coefficient (r) of 0.9973. The limit of detection was 1 ng/ml at a signal-to-noise ratio of 3:1. Recoveries determined for three concentrations range between 86.14% and 88.98.1%. Intra-day and inter-day relative standard deviation values were found to be within 6.43-11.35% and 9.82-13.05%, respectively. Using the developed method, a pharmacokinetic study was performed for desipramine (as active metabolite of imipramine).