Time resolved analysis of risperidone and 9-hydroxy-risperidone in hair using LC/MS-MS
Faculty of Pharmaceutical, Biomedical and Veterinary Sciences. Pharmacy
Journal of chromatography : B: analytical technologies in the biomedical and life sciences. - Amsterdam, 2002, currens
, p. 2589-2592
University of Antwerp
Risperidone (RSP) is a second generation anti-psychotic drug used for the treatment of schizophrenia and anxiety disorders. In the last decades, clinical applications of hair analysis have received an increasing attention, because of its wide surveillance window. In this work, we describe a simple and fast method for detection and quantification of RSP and its major metabolite, 9-OH-risperidone (9-OH-RSP), in human hair. The validated method (cv of interday precision, intraday precision and accuracy < 15%, r2 of the calibration curves > 0.98, limit of detection (LOD) was 0.90 pg/mg hair (RSP) and 1.52 pg/mg hair (9-OH-RSP), the lower limit of quantification (LLOQ) were 1.8 and 4.56 pg/mg, respectively, extraction yield were 86.9% for RSP and 86.7% for 9-OH-RSP) was successfully applied to quantify both substances in the hair of psychiatric patients treated with RSP. After washing, pulverisation, incubation in an ultrasound bath and liquid/liquid extraction of the hair samples, quantification was performed using LC/MS-MS in selected reaction monitoring mode with methaqualone as internal standard. Concentrations for RSP and its major metabolite ranged from 36 to 4765 pg/mg and from 14 to 57 pg/mg, respectively in the different hair segments. These preliminary results indicate a better relationship between the administered dose and hair concentration for 9-OH-RSP than for the parent drug. Furthermore, the RSP/9-OH-RSP ratio varied from 1 to 83.