Simultaneous determination of estramustine phosphate and its four metabolites in human plasma by liquid chromatography-ionspray mass spectrometry.

A sensitive and selective method, using liquid chromatography-ionspray mass spectrometry, was developed and validated for the simultaneous determination of Estracyt (estramustine phosphate) and its four metabolites, estramustine, estromustine, estrone and estradiol, in human plasma. Deuterated internal standards were available for all analytes. The five compounds were extracted from plasma by protein precipitation with acetonitrile.

Quantitative determination of paclitaxel in human plasma using semi-automated liquid-liquid extraction in conjunction with liquid chromatography/tandem mass spectrometry.

This paper describes a high-throughput sample preparation procedure combined with LC-MS/MS analysis to measure paclitaxel in human plasma. Paclitaxel and an internal standard were extracted from plasma by a semi-automated robotic method using liquid-liquid extraction. Thereafter compounds were separated on a RP C18 column.

Simultaneous determination of JTT-501 and its main metabolite in human plasma by liquid chromatography-ionspray mass spectrometry.

An LC-MS-MS analytical method was developed for the determination of a new antidiabetic agent, JTT-501 and its main metabolite (JTP-20604) in human plasma. The compounds were isolated from plasma by protein precipitation before analysis by HPLC with atmospheric pressure positive ionisation MS-MS detection. An isotopically labelled analog of JTT-501 was used as the internal standard.

Determination of 4-demethoxy-3'-deamino-3'-aziridinyl-4'-methylsulphonyldaunorubicin+ ++ and its 13-hydroxy metabolite by direct injection of human plasma into a column-switching liquid chromatography system with mass spectrometric detection.

A selective, sensitive and fully automated column-switching LC system using direct injection of human plasma followed by mass spectrometry (MS) detection was developed and validated to determine the concentrations of 4-demethoxy-3'-deamino-3'-aziridinyl-4'-methylsulphonyldaunorubicin++ + (PNU-159548) and its 13-hydroxy metabolite (PNU-169884). A 50-microl human plasma sample was directly introduced into a C4-alkyl-diol silica clean-up column separating analytes from proteins and polar endogenous compounds using water and methanol as the mobile phase. The fraction containing PNU-159548 and its metabolite was back-flushed and transferred to the analytical column.

Determination of PNU 157706, a new dual inhibitor of 5alpha-reductase, in rat plasma by high-performance liquid chromatography with ultraviolet detection.

A HPLC procedure was developed and validated for determining nanogram per milliliter concentrations of the dual 5alpha-reductase inhibitor PNU 157706 in rat plasma. The compound was extracted from plasma with diethyl ether followed by purification using a CN cartridge. The chromatographic separation was performed with a C18 column using a water-acetonitrile-methanol mixture as eluent.

Determination of turosteride, a new inhibitor of 5 alpha-reductase, in human plasma by high-performance liquid chromatography with ultraviolet detection.

A sensitive and specific HPLC method for the determination of turosteride in human plasma was developed and validated. Turosteride was extracted from plasma with diethyl ether. Further purifications of the fraction extracted were performed sequentially by solid-phase extraction using a CN cartridge and by liquid-liquid partition between n-hexane and acetonitrile.

Enantioselective determination of FCE 28833, a new potential antiischemic agent, in gerbil plasma using column switching HPLC with UV detection.

A sensitive and selective high performance liquid chromatographic method using an automated column switching technique for the determination of FCE 28833 enantiomers in gerbil plasma was developed. After solid-liquid extraction using a Supelcosil C18 cartridge, FCE 28833 was eluted on a clean-up column (Spherisorb CN) and the enantiomers were separated using an analytical chiral column (Crownpack CR(+)). The mobile phase (15% methanol in HClO4 1 mM) was directed through the columns at a flow rate of 1 ml/min and the fraction eluted between 13 and 40 min was transferred from the clean-up column into the analytical column.

High-performance liquid chromatographic determination of FCE 24928, a new aromatase inhibitor, in human plasma.

A sensitive and selective high-performance liquid chromatographic method for the determination of FCE 24928 (4-amino-androsta-1,4,6-triene-3,17-dione) in human plasma is reported. The drug was extracted from buffered (pH = 8) plasma samples with methylene chloride-isooctane, then analysed by reversed-phase liquid chromatography. Quantitation was achieved by ultraviolet detection of the eluate at 238 nm.

Determination of FCE 23884, a new ergolene derivative, and its possible metabolite, the 6-nor-derivative in plasma by high-performance liquid chromatography with fluorescence detection.

A sensitive and selective high-performance liquid chromatographic method for the determination of FCE 23884 and its 6-nor-derivative (FCE 26506) in plasma has been developed. After buffering the plasma samples, the compounds and the internal standard were extracted with ethyl ether-n-octanol (9:1, v/v), back-extracted into 0.01 M phosphoric acid and then analysed by reversed-phase liquid chromatography.

Pharmacokinetics of acipimox and of its N-deoxy metabolite following single and repeated oral administration to healthy volunteers.

The aim of the present study was to evaluate the plasma pharmacokinetics of acipimox and of its N-deoxy metabolite (5-methylpyrazine-2-carboxylic acid, MPCA) following single and repeated administration of 250 mg acipimox (thrice daily, for 6 days) to ten healthy volunteers. Mean maximum concentration, the corresponding time, area under the curve extrapolated to infinity and elimination half-life values of acipimox after single administration were equal to 5.74 micrograms/ml (range 2.

Pharmacokinetics of iododoxorubicin in the rat, dog, and monkey.

The pharmacokinetics of iododoxorubicin (I-DOX) have been studied after single dose administration in the rat (iv and po), dog (iv and po), and monkey (iv). Plasma levels and amounts in urine were monitored by HPLC for both I-DOX and its biologically active metabolite, iododoxorubicinol (I-DOXOL). Plasma levels of I-DOX after iv administration could be described by a three-exponential curve with extremely fast initial phase.