title: Analysis of risperidone and 9-hydroxyrisperidone in human plasma, urine and saliva by MEPS-LC-UV.
abstract: Risperidone is currently one of the most frequently prescribed atypical antipsychotic drugs; its main active metabolite 9-hydroxyrisperidone contributes significantly to the therapeutic effects observed. An original analytical method is presented for the simultaneous analysis of risperidone and the metabolite in plasma, urine and saliva by high-performance liquid chromatography coupled to an original sample pre-treatment procedure based on micro-extraction by packed sorbent (MEPS). The assays were carried out using a C8 reversed-phase column and a mobile phase composed of 73% (v/v) acidic phosphate buffer (30 mM, pH 3.0) containing 0.23% triethylamine and 27% (v/v) acetonitrile. The UV detector was set at 238 nm and diphenhydramine was used as the internal standard. The sample pre-treatment by MEPS was carried out on a C8 sorbent. The extraction yields values were higher than 92% for risperidone and 90% for 9-hydroxyrisperidone, with RSD for precision always lower than 7.9% for both analytes. Limit of quantification values in the different matrices were 4 ng/mL or lower for risperidone and 6 ng/mL or lower for the metabolite. The method was successfully applied to plasma, urine and saliva samples from psychotic patients undergoing therapy with risperidone, with satisfactory accuracy results (recovery>89%) and no interference from other drugs. Thus, the method seems to be suitable for the therapeutic drug monitoring of schizophrenic patients using the three different biological matrices plasma, urine and saliva.
authors.affiliation: Laboratory of Pharmaco-Toxicological Analysis, Department of Pharmaceutical Sciences, Faculty of Pharmacy, Alma Mater Studiorum-University of Bologna, Via Belmeloro 6, I-40126 Bologna, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Mandrioli
authors.forename: Laura
authors.initials: L
authors.lastname: Mercolini
authors.forename: Domenico
authors.initials: D
authors.lastname: Lateana
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Boncompagni
authors.forename: Maria Augusta
authors.initials: MA
authors.lastname: Raggi
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D006801:Humans; D007555:Isoxazoles / Q000032:analysis* / Q000097:blood / Q000737:chemistry / Q000652:urine; D016014:Linear Models; D000068882:Paliperidone Palmitate; D011618:Psychotic Disorders; D011743:Pyrimidines / Q000032:analysis* / Q000097:blood / Q000737:chemistry / Q000652:urine; D015203:Reproducibility of Results; D018967:Risperidone / Q000032:analysis* / Q000097:blood / Q000737:chemistry / Q000652:urine; D012463:Saliva / Q000737:chemistry*; D012680:Sensitivity and Specificity; D052617:Solid Phase Microextraction / Q000379:methods*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D007555:Isoxazoles; D011743:Pyrimidines; D018967:Risperidone; D000068882:Paliperidone Palmitate