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Aim: With microsamples of blood, full pharmacokinetic profiles from individual animals can be obtained as an alternative to the sparse-sampling approach, where conventional volume samples from several animals are required. However, microsamples require assays that are more sensitive. Methods: The sensitivity of the LC–MS assay was increased 47-fold using microflow LC–MS. Results & conclusion: By […]

Background: Aimed to simultaneously measure linezolid, voriconazole, cefoperazone and fluconazole in human plasma suitable for therapeutic drug monitoring applications, a robust, rapid and easy-to-use HPLC–MS/MS approach was developed and validated. Materials & methods: Protein precipitation was used to prepare analytes from 100 μl plasma. HPLC was employed for analyte separation, and quantification was conducted via

Aim: Isobutyrylcarnitine (IBC) is a possible biomarker for hepatic OCT1, as IBC plasma concentrations are reduced when OCT1 is inhibited. An accessible, characterized assay is needed to quantitate IBC in human plasma. Materials & methods: A triple quadrupole MS surrogate matrix assay for the quantitation of IBC was characterized to support a first-in-human study. Results: An assay for IBC quantitation was fully characterized for accuracy, precision, selectivity and parallelism. IBC was measured in a clinical study and the data were

This study aimed to establish an isotope dilution LC–MS/MS method for the determination of folic acid, 5-formyltetrahydrofolate and 5-methyltetrahydrofolate in human serum. This method was then used to quantify these three folate forms in the healthy adult population and supplement users. A stable 96-well solid-phase extraction system was used to prepare serum samples. The highly

Background: Valdecoxib is an active metabolite of parecoxib that has a high binding rate with plasma protein. Hypoalbuminemia may affect the pharmacokinetics process of valdecoxib. Method & results: A rapid LC–MS/MS method was applied to assay parecoxib and valdecoxib in hypoalbuminemia and healthy rats. Hypoalbuminemia rat models were established by intravenous injection of doxorubicin. The

Background: Motilin is a peptide-structured gastrointestinal system hormone. In this study, a sensitive HPLC-fluorescence detection method was developed and validated for the quantification of motilin in human plasma. Materials & methods: Optimization processes were carried out with the experimental design methodology. Analyses were performed on a C8 column (4.6 × 150 mm, 3.5 μm particles)

Background: Although the fit-for-purpose approach has been proposed for biomarker assay validation, practical data should be compiled to facilitate the predetermination of acceptance criteria. Methods: Immunoaffinity LC–MS was used to analyze glucagon-like peptide-1 as a model biomarker in six laboratories. Calibration curve, carryover, parallelism, precision, relative accuracy and processed sample stability were evaluated, and their

Background: The authors present a validated method for the simultaneous quantification of asundexian (BAY 2433334) and its pharmacologically inactive major human metabolite M-10 from human plasma and its application in clinical study sample analysis. Materials & methods: Sample preparation was performed by protein precipitation followed by reverse phase HPLC and positive/negative ESI-MS/MS. Results: Assay working

As the desire for a shortened design/make/test/learn cycle increases in early drug discovery, the pressure to rapidly deliver drug metabolism pharmacokinetic data continues to rise. From a bioanalytical standpoint, in vitro assays are challenging because they are amenable to automation and thus capable of generating a high number of samples for analysis. To keep up

While bioanalytical outsourcing is widely adopted in the pharmaceutical industry, AbbVie is one of the few large biopharmaceutical companies having an internal bioanalytical unit to support nearly all its drug metabolism and pharmacokinetic studies. This article highlights our experience and perspective in building an integrated and centralized laboratory to provide early discovery and preclinical-stage bioanalytical