Simultaneous determination of chlorpromazine and levomepromazine in human plasma and urine by high-performance liquid chromatography using electrochemical detection

Ultrasensitive SERS substrate for label-free therapeutic drug monitoring of chlorpromazine hydrochloride and aminophylline in human serum

Surface-enhanced Raman spectroscopy (SERS) has been widely used in the field of therapeutic drug monitoring (TDM) because of its powerful fingerprinting capability. In this paper, we used an in situ synthesis method to anchor Ag nanoparticles (AgNPs) on the surface of MIL-101(Cr) to obtain MIL-101(Cr)@Ag. Owing to the large specific surface area and ultra-high porosity of MIL-101(Cr)@Ag, we developed a method for the determination of chlorpromazine hydrochloride (CPZ) and aminophylline (AMP) in human serum by using it as a solid-phase extraction sorbent and SERS substrate. The label-free TDM-SERS method was able to evaluate the levels of CPZ and AMP in serum samples with detection limits as low as 8.91 × 10^-2 µg/mL and 3.4 × 10^-2 µg/mL, respectively. In addition, influencing factors including sample solution pH, AgNO₃ concentration, drug adsorption time, and the amount of sample solution were optimized. This protocol provides a new method with good selectivity, stability, reproducibility, homogeneity, and sensitivity for the determination of small-molecule drug content in serum samples. This label-free TDM-SERS method will help to achieve rapid individualized dosing regimens in clinical practice and has potential applications in the field of TDM.

Simple and simultaneous determination for 12 phenothiazines in human serum by reversed-phase high-performance liquid chromatography

A high-performance liquid chromatographic method has been developed for the simultaneous analysis of the 12 phenothiazines (chlorpromazine, fluphenazine, levomepromazine, perazine, perphenazine, prochlorperazine, profenamine, promethazine, propericiazine, thioproperazine, thioridazine and trifluoperazine) in human serum using HPLC/UV. The separation was achieved using a C(18) reversed-phase column (250 mm x 4.6 mm I.D., particle size 5 microm, Inersil ODS-SP). The mobile phase, consisting of acetonitrile-methanol-30 mM NaH(2)PO(4) (pH 5.6) (300:200:500, v/v/v), was delivered at a flow rate of 0.9 mL/min and UV detection was carried out at 250 nm. The recoveries of the 12 phenothiazines spiked into serum samples were 87.6-99.8%. Regression equations for the 12 phenothiazines showed excellent linearity, with detection limits of 3.2-5.5 ng/mL for serum. The inter-day and intra-day coefficients of variation for serum samples were commonly below 8.8%. The selectivity, accuracy and precision of this method are satisfactory for clinical and forensic purposes. This sensitive and selective method offers the opportunity for simultaneous screening and quantification of almost all phenothiazines available in Japan for the purposes of clinical and forensic applications.

Determination of a novel xanthine derivative, MKS 213-492, in plasma by high-performance liquid chromatography with electrochemical detection

A reversed-phase liquid chromatographic method with coulometric detection has been developed for the determination of free MKS 213-492 (a novel xanthine derivative) in plasma. This method is based on a simple and rapid plasma extraction procedure using precolumn-switching. The oxidation of this pharmacologically active xanthine derivative was optimized with respect to applied potential, pH of mobile and rinsing phase and rinsing time. The detection limit for MKS 213-492 was found to be 54 pg/injection.

Quantification of chlorprothixene, levomepromazine and promethazine in human serum using high-performance liquid chromatography with coulometric electrochemical detection

Isocratic reversed-phase high-performance liquid chromatography with coulometric electrochemical detection was optimised to quantify the neuroleptic drugs chloroprothixene, levomepromazine, and promethazine in human serum. The method involves extraction of the neuroleptic drugs in n-heptane-isoamylalcohol from the alkalinized serum, followed by chromatographic separation on a Nucleosil CN column with acetonitrile-pyridine-sodium acetate buffer as the mobile phase. The extraction recovery was > 85% for each neuroleptic drug. The sensitivity and selectivity required for pharmacokinetic studies was obtained with a dual coulometric analytical cell operating in the oxidative screen mode. The lower limit of detection in human serum for chlorprothixene, levomepromazine, and promethazine, was 0.5, 0.2 and 0.1 ng/ml, respectively. A linear relationship (r2 > 0.99) was obtained between the concentrations of each neuroleptic drug and the detector signal. The accuracy of the quality control samples was +/- 7% for each neuroleptic drug with a precision within 9.5%, 8.1% and 13.5% for chlorprothixene, levomepromazine, and promethazine, respectively. The neuroleptic drugs were stable in acetonitrile and human serum for at least six months when stored at -20 degrees C. This method is applicable to analyze a large number of serum samples for pharmacokinetic studies of the neuroleptic drugs.

High performance liquid chromatographic determination of levomepromazine in human breast milk and serum using solid phase extraction

A high performance liquid chromatographic (HPLC) method has been developed for the determination of levomepromazine in human breast milk and serum. The levomepromazine was extracted by a rapid and simple extraction method using a Sep-Pak C18 cartridge. The extracts were separated by HPLC on a C8 bonded reversed phase column and detected by UV absorbance at 254 nm. There was no interference with endogenous substance in human breast milk and serum. A linear relationship was obtained for the levomepromazine over the concentration range of 10-300 ng/mL. The recoveries of levomepromazine added to human breast milk and serum were 92.5-99.1% and 86.9-103.9%, respectively.

Determination of chlorpromazine in human breast milk and serum by high-performance liquid chromatography

A high-performance liquid chromatographic (HPLC) assay was developed for the determination of chlorpromazine in serum and human breast milk. Chlorpromazine in serum and human breast milk was extracted by a rapid and simple procedure based on C18 bonded-phase extraction, and a reversed-phase HPLC separation technique was developed. Chlorpromazine and levomepromazine as the internal standard were detected by ultraviolet absorbance at 254 nm. Determination was possible for chlorpromazine in the concentration range 10-300 ng/ml. The recoveries of chlorpromazine added to serum and human breast milk were 80.1-87.6 and 80.3-84.4%, respectively, with coefficients of variation of less than 10.2 and 7.8%. The method is applicable to drug level monitoring in the serum and human breast milk of patients treated with chlorpromazine.

Determination of a new calcium antagonist, sesamodil fumarate (SD-3211), and its metabolite in plasma by liquid chromatography with electrochemical detection

A sensitive and selective high-performance liquid chromatographic method is described for the determination of a novel calcium antagonist, (+)-(R)-3,4-dihydro-2-[5-methoxy-2-[3-[N-methyl-N-[2-[(3,4- methylenedioxy)phenoxy]ethyl]amino]propoxy]phenyl]-4-methyl-3-oxo-2H- 1,4-benzothiazine hydrogen fumarate (sesamodil fumarate; JAN, SD-3211, I), and its N-desmethylated metabolite (II) in plasma. Compounds I and II and an internal standard were isolated from plasma by solid-phase and liquid-liquid extraction. The extract was chromatographed on a reversed-phase C18 column, and the compounds of interest were detected by dual coulometric electrodes operated in an oxidative screen mode. The limit of determination for both I and II was at least 0.4 ng/ml in plasma. The utility of the assay was demonstrated by determining plasma levels of I and II in five dogs administered an oral dose of 60 mg of the drug.

High-performance liquid chromatographic separation and determination of 2-(diethylamino)ethyl diphenylpropylacetate and its metabolites from biological samples

A high-performance liquid chromatographic method for the determination of 2-(diethylamino)ethyl diphenylpropylacetate (SKF 525-A; Proadifen), its two deethylated metabolites and a hydrolytic metabolite in biological samples has been developed. From many solvent systems investigated the compounds are best separated on an ODS/Sil-X column using an acetonitrile-phosphate buffer system containing 0.2% decylamine. The use of acetonitrile overcomes limitations associated with previously published methods for separating basic compounds where decylamine was used in a methanolic eluent. With the sampling procedures used, overall recoveries from biological tissues were around 80%. The chromatographic system also separates three tricyclic antidepressants which can be used as internal standards.

Determination of chlorprothixene and its sulfoxide metabolite in plasma by high-performance liquid chromatography with ultraviolet and amperometric detection

This communication describes a rapid, sensitive and selective method for the assay of chlorprothixene and its sulfoxide metabolite in human plasma, using reversed-phase high-performance liquid chromatography. Alkalinized plasma was extracted with heptane--isoamyl alcohol (99:1), after addition of thioridazine as the internal standard. The residue obtained after evaporation of this extract was chromatographed on a cyano column, using acetonitrile--0.02 M potassium dihydrogen phosphate pH 4.5 (60:40) as the mobile phase with ultraviolet (229 nm) detection. Quantitation was based on peak height ratios over the concentration range of 5.0-50.0 ng/ml for both compounds with 85% and 90% recovery for chlorprothixene and its sulfoxide metabolite, respectively, using a 1.0-ml plasma sample. The assay chromatographically resolves chlorprothixene and the sulfoxide metabolite from the N-desmethyl metabolite, which can only be semi-quantitated owing to low and variable recoveries. The method was used to obtain plasma concentration versus time profiles in two subjects after oral administration of 100 mg of chlorprothixene suspension and in two additional subjects following overdosages of chlorprothixene estimated to exceed several hundred milligrams. These analyses demonstrated that the sulfoxide metabolite is the predominant plasma component following therapeutic administration and overdosages. High-performance liquid chromatography with oxidative amperometric detection with the glassy carbon electrode was also evaluated. Although this procedure demonstrated comparable sensitivity and precision to ultraviolet detection for the analysis of chlorprothixene and N-desmethyl chlorprothixene, the sulfoxide metabolite could not be measured with high sensitivity (less than 100 ng/ml) owing to endogenous interferences. Hence the utility of this alternative assay technique is limited.

Subnanogram quantitation of chlorpromazine in plasma by high-performance liquid chromatography with electrochemical detection

A specific and sensitive high-performance liquid chromatographic (HPLC) method for the quantitative determination of subnanogram levels of chlorpromazine in plasma is described. Following extraction of chlorpromazine and the internal standard, prochlorperazine, HPLC analysis is carried out on a cyano column with a mobile phase consisting of 0.1 M ammonium acetate in acetonitrile (10:90 v/v). The use of oxidative thin-layer amperometric detection allowed the quantitation of 0.25 ng of chlorpromazine/ml of plasma with a coefficient of variation of 5.1%. The HPLC method has adequate sensitivity to follow plasma concentration-time profiles up to 24 hr following low single oral doses of chlorpromazine in healthy volunteers.