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.