DETERMINATION OF RISPERIDONE AND 9-HYDROXYRISPERIDONE IN HUMAN PLASMABY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH ELECTROCHEMICAL DETECTION

A method for the determination of risperidone and its active metabolit e 9-hydroxyrisperidone in human plasma has been developed. The procedu re involved a multi-step liquid-liquid extraction with an internal sta ndard. The parent drug and its metabolite were separated on a cyano co lumn used in the reversed-phase model. The coulometric detection allow s quantification in the range 2-100 ng/ml. The precision, accuracy and specificity have been checked, and show that the method is reliable f or clinical studies.