rapid high performance liquid chromatographic determination of risperidone in human plasma

a simple, rapid and sensitive high-performance liquid chromatographic (hplc) method for the determination of risperidone in human plasma was developed. an hplc system based on a nucleosil c8 column (150?4 mm) and a uv detector (?= 280 nm) were used. a mixture of sodium dihydrogen phosphate buffer-acetonitrile (55:45, v/v) adjusted to ph 6.0 at a flow rate of 1.5 ml min-1 was used as mobile phase. the proteins were precipitated with an acetonitrile solution containing diltiazem as internal standard and the average recovery was 93.9±3.4%. the detection limit for risperidone in plasma was 0.5 ngml-1. the calibration curve was linear over the concentration range 2-50 ngml-1. the inter-day and intra-day assay coefficients of variation were found to be less than 5%. the present validated method was successfully used for pharmacokinetic studies of risperidone in human subjects.