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.