Development and validation of a reverse phase High Performance Liquid Chromatographic method, using standard addition calibration, for determination of risperidone in human plasma

Risperidone is a drug of choice in the management of psychosis and high performance liquid chromatography (HPLC) is regarded as the most sensitive and accurate method for quantitative analysis of risperidone, as well as other drugs having low plasma concentrations in biological fluids. A simple and accurate HPLC method was developed for the determination of risperidone in human plasma using the standard addition calibration technique to augment the weak signals due to low plasma concentrations of risperidone. Risperidone was eluted using isocratic mode with a mobile phase of methanol: acetonitrile (60:40) on a Chemisil ODS C18 column (250 mm×4.6 mm i.d., 5 μ particle size). The sample injection volume, flow rate, column temperature and wavelength of detection were set at 10 µl, 1.0 ml/min, 35 ˚C and 280 nm respectively. The run time for the method was 7 minutes, with risperidone having a retention time of 3.566 minutes. The method was linear within the concentration 10-50 ng/ml (R2= 0.998), with LOD and LOQ of 0.13 and 0.40 ng/ml respectively. The precision and relative error was 3.44 % and 3.38 % respectively. The developed method can be employed in the quantitative determination of risperidone in pharmacokinetic and bioequivalence studies.