chlorpromazine-n-oxide and 7-hydroxychlorpromazine

The concentrations of chlorpromazine (CPZ) and six of its metabolites in patient plasma samples that had been stored for 24 h at -20 degrees C, for 1 week at -20 degrees C, and for 4 weeks at -70 degrees C were compared. The concentrations of CPZ and six of its metabolites in human plasma spiked with known concentrations and stored at -70 degrees C for either 3 or 12 months were also compared. No significant difference was seen in the concentrations after storage under nitrogen and analysis by a high-performance liquid chromatography technique.

Topics: Chlorpromazine; Chromatography, High Pressure Liquid; Drug Stability; Drug Storage; Humans; Schizophrenia

Antibodies specific to chlorpromazine N-oxide (CPZNO) were produced in rabbits immunized with a hapten-bovine serum albumin conjugate, which was prepared by linking the 7-position of the phenothiazine ring of the metabolite to the protein via a 4-carbon bridge. An extraction radioimmunoassay (RIA) was developed using this antiserum and shown to have adequate sensitivity and specificity for determination of plasma concentrations of CPZNO in the presence of chlorpromazine (CPZ) and its major metabolites. It was used together with the previously developed RIAs for CPZ, chlorpromazine sulfoxide (CPZSO), and 7-hydroxychlorpromazine (7-OHCPZ) to study the pharmacokinetics of CPZ and these metabolites in five healthy volunteers after they received a single 50-mg oral dose of CPZ. It is interesting to note that peak plasma concentrations of CPZNO were considerably higher than CPZ, and the apparent elimination half-lives of this metabolite were shorter than those of CPZ.

Topics: Adult; Chlorpromazine; Chromatography, High Pressure Liquid; Chromatography, Thin Layer; Half-Life; Humans; Male; Plasma; Radioimmunoassay; Spectrophotometry, Ultraviolet

A new high-performance liquid chromatographic (HPLC) procedure for the simultaneous determination of chlorpromazine and its six metabolites, namely, 7-hydroxy-chlorpromazine, N-monodesmethyl-chlorpromazine, 7-hydroxy-N-monodesmethyl-chlorpromazine, chlorpromazine-sulfoxide, chlorpromazine N-oxide, and N-monodesmethyl-chlorpromazine-sulfoxide, in plasma was developed and compared with four radioimmunoassay (RIA) procedures that measured separately chlorpromazine, 7-hydroxy-chlorpromazine, chlorpromazine-sulfoxide, and chlorpromazine N-oxide. The results of this study for the determination of plasma levels in four healthy volunteers given a 100-mg single oral dose of chlorpromazine hydrochloride demonstrated that in some cases, strong correlations could be found between the plasma levels determined by the HPLC and RIA procedures, whereas in other cases, there was a lack of strong correlation. The discrepancies observed were not only due to nonspecificity of the immunoassay procedures employed, but also to a lack of rigorous specificity of the HPLC procedure in plasma samples from dosed humans. These findings clearly indicate that even a chemical method of analysis, such as HPLC, has its limitations in its application to multianalyte analysis, as is the case with drugs like chlorpromazine.

Topics: Chlorpromazine; Chromatography, High Pressure Liquid; Male; Monitoring, Physiologic; Radioimmunoassay; Regression Analysis