Determination of risperidone and 9-hydroxyrisperidone in human plasma by high-performance liquid chromatography: application to therapeutic drug monitoring in Japanese patients with schizophrenia
ABSTRACT A high-performance liquid chromatographic method has been developed for the simultaneous determination of risperidone and its major active metabolite 9-hydroxyrisperidone in plasma. Risperidone and 9-hydroxyrisperidone in plasma were extracted using a CN bonded-solid phase cartridge, followed by, C4 reversed-phase HPLC separation. Risperidone, 9-hydroxyrisperidone and trazodone as an internal standard were detected by ultraviolet absorbance at 280 nm. It was possible to determine risperidone in the concentration range of 1.0-100.0 ng/ml(-1) and 9-hydroxyrisperidone at a range of 2.0-200.0 ng/ml(-1). The detection limits of risperidone and 9-hydroxyrisperidone were 0.5 and 1.0 ng/ml(-1), respectively. The mean recoveries of risperidone and 9-hydroxyrisperidone added to plasma were less than 92.0 and 92.6%, with a coefficient of variation of less than 10.6 and 10.5%, respectively. This method has been used for the simultaneous determination of steady-state plasma concentration (Css) of risperidone and 9-hydroxyrisperidone in schizophrenic patients treated with 3-, 6-, and 12-mg risperidone oral doses per day.
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ABSTRACT: A carbon paste electrode (CPE) modified with multi-walled carbon nanotube (MWCNT) was proposed for determination of Risperidone (Risp). The method was based on adsorptive accumulation of the Risp on to paste electrode, followed by reduction of the accumulated species by voltammetric scan. The parameters influencing the peak current were optimized. Under the optimum conditions, the electrode established linear response over a wide range of Risp concentrations (0.04 to 10 mmol L À1), the detection limit was 0.012 mmol L À1 (after 150 s accumulation). The method was applied to the determination of Risp in a pharmaceutical preparation and in human serum samples, and satisfactory results were obtained.Analytical methods 05/2012; 4(5). DOI:10.1039/c2ay05688g · 1.94 Impact Factor
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ABSTRACT: Electrochemical properties and diffusion-adsorption behavior of risperidone (RPN), an anti-physcotic drug, on hanging mercury drop electrode (HMDE) were carried out in Britton-Robinson (BR) buffer. Some electrochemical parameters such as diffusion coefficient, number of transferred electrons and proton participated to its reduction mechanism and surface coverage coefficient were calculated from the results of cyclic voltammetry, square-wave voltammetry and constant potential electrolysis. RPN was found to be reduced with single two-electron/ two-proton quasi-reversible mechanism controlled mainly by adsorption with some diffusion contribution at the potential about -1.58 V (vs Ag|AgCl electrode). Experimental parameters were optimized to develop a new, accurate, rapid, selective and simple square-wave cathodic adsorptive stripping voltammetric (SWCAdSV) method for direct determination of RPN in pharmaceutical dosage forms, spiked human urine and human serum samples without time-consuming steps prior to drug assay. This method was based on the relation between the peak current and the concentration of RPN and it was recognized that peak current of reduction wave linearly changes with the concentration of RPN in the concentration range of 1.5-150 nM, when optimum preconcentration potential -0.65 V and optimum preconcentration time 60 s were applied. In this method, limit of detection (LOD) was found as 5.18 nM (2.12 ppb). The method was successfully applied to determine the RPN content of commercial pharmaceutical preparations, spiked human serum and spiked human urine. The method was found to be highly accurate and precise, having a relative standard deviation of less than 4.80% for all applications.Collection of Czechoslovak Chemical Communications 03/2011; 76(3):159. DOI:10.1135/cccc2010156 · 1.14 Impact Factor
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ABSTRACT: The aim of this review is to provide information for interpreting outcome results from monitoring of antipsychotics in biological samples. A brief overview of the working mechanisms, pharmacological effects, drug interactions, and analytical methods of classical and atypical antipsychotics is given. Nineteen antipsychotics were selected based on their importance in the worldwide market as follows: amisulpride, aripiprazole, asenapine, bromperidol, clozapine, flupenthixol, haloperidol, iloperidone, lurasidone, olanzapine, paliperidone, perphenazine, pimozide, pipamperone, quetiapine, risperidone, sertindole, sulpiride, and zuclopenthixol. A straightforward relationship between administered dose, plasma or serum concentration, clinical outcome, or adverse effects is often lacking. Nowadays, focus lies on therapeutic drug monitoring and individualized therapy to find adequate treatment, to explain treatment failure or nonresponse, and to check patient compliance. However, extensive research in this field is still mandatory.Therapeutic drug monitoring 12/2012; 34(6):629-651. DOI:10.1097/FTD.0b013e3182708ec5. · 1.93 Impact Factor