Quantification of taxanes in biological matrices: a review of bioanalytical assays and recommendations for development of new assays

Deuterium- and Tritium-Labelled Compounds: Applications in the Life Sciences

Hydrogen isotopes are unique tools for identifying and understanding biological and chemical processes. Hydrogen isotope labelling allows for the traceless and direct incorporation of an additional mass or radioactive tag into an organic molecule with almost no changes in its chemical structure, physical properties, or biological activity. Using deuterium-labelled isotopologues to study the unique mass-spectrometric patterns generated from mixtures of biologically relevant molecules drastically simplifies analysis. Such methods are now providing unprecedented levels of insight in a wide and continuously growing range of applications in the life sciences and beyond. Tritium (³ H), in particular, has seen an increase in utilization, especially in pharmaceutical drug discovery. The efforts and costs associated with the synthesis of labelled compounds are more than compensated for by the enhanced molecular sensitivity during analysis and the high reliability of the data obtained. In this Review, advances in the application of hydrogen isotopes in the life sciences are described.

A review of high performance liquid chromatographic-mass spectrometric urinary methods for anticancer drug exposure of health care workers

This review describes published high performance liquid chromatography/mass spectrometry (HPLC-MS) methods for the determination of anticancer drugs in human urine as non-invasive tool for monitoring of health care worker exposure to antineoplastic and cytotoxic drugs. HPLC-MS is a sensitive and specific method for analysis of anticancer drugs and their metabolites in biological fluids. In this review, a tabular summary and overview of published HPLC-MS methods are presented, as well as future trends and limitations in this area of research.

HPLC-MS/MS method for quantification of paclitaxel from keratin containing samples

Local drug delivery of paclitaxel is becoming ever more prevalent. As complex drug/excipient combinations are being developed and tested, new high performance liquid chromatography-mass spectrometry (HPLC-MS) techniques capable of quantifying paclitaxel from such formulations are needed. Here a method for quantifying paclitaxel from aqueous, protein and oil containing samples was developed and validated. Keratin, derived from human hair, is the protein component/paclitaxel excipient in the development and validation of said method. The novelty of this method is described by its ability to overcome water solubility issues and address clean-up of residual solvents in clinical grade paclitaxel injection composition. The method evaluates tert-butyl methyl ether and ethanol as extraction solvents with an extraction efficiency of 31.9±2.3% and 86.4±4.5% respectively. Upon evaporation and rehydration, samples were evaluated by HPLC-MS and a method was developed for paclitaxel quantification. The method developed had an inter-day precision of 9.1% relative standard deviation and an intra-day precision of 4.3% relative standard deviation normalized to a docetaxel internal standard. The described method is applicable to any aqueous paclitaxel sample containing protein and/or oils.

Analytical characterization of IgG–cTpp and IgG–Mn-cTpp conjugates

Herein, the conjugation of carboxylated tetraphenylporphyrin or its derivative containing manganese cation and model protein — immunoglobulin G is presented. The obtained IgG–cTpp and IgG–Mn-cTpp conjugates were subsequently used for model immunoassays construction. The IgG–cTpp formation was confirmed using size-exclusion chromatography. Thanks to the unique properties of applied labels the assay analysis was carried out with both spectrophotometric and spectrofluorimetric detection. The assays were performed creating semi-quantitative detection system using 96-well plates. The incubation time, ensuring full saturation of the surface with secondary antibodies was also optimized. Moreover, in the case of IgG–Mn-cTpp conjugates we present the possibility of both direct and indirect determination of the label, the latter based on the catalytic activity of Mn-cTpp, which allows for amplification of the measured signal. We proved that both cTpp and Mn-cTpp may be successfully used for protein labeling and serve as universal tracers for various formats of affinity assays and sensors.