Pharmacokinetic study of granisetron in human plasma measured by UPLC-MS/MS and its use in healthy Chinese subjects.

In this study, a rapid, simple and sensitive UPLC-MS/MS method was established for the quantification of granisetron in human plasma for the prevention of vomiting after radiotherapy and chemotherapy. The precipitated proteins were extracted and gradient eluted on a ZORBAX Eclipse Plus C18 column (2.1×50mm, 1.8µm) to achieve ideal chromatographic separation. Multiple reaction mode (MRM) was performed using a Turboion Spray API5500 mass spectrometer equipped with Electron Spray Ionization (ESI). For method validation, good linearity was observed for each analyte of interest in the validation concentration range of 0.05 to 20.0ng/mL. The CV% of inter-batch and intra-batch precision were in the range of -3.6% to 4.7% and the precision of both inter-batch and intra-batch was ≤15.0%. In addition, the method had the advantage of a low matrix effect. In human plasma, all analytes remained stable for 2 hours when kept at room temperature; samples were stable within the autosampler (5°C) for 141 h after preparation and after four freeze-thaw cycles at -20°C and -70°C for 48 days. The UPLC-MS method that had been validated was later utilized for the pharmacokinetic investigation of granisetron hydrochloride tablets in orally administered doses to healthy Chinese volunteers, both before and after meals.

A validated high-performance liquid chromatography method for detecting geniposide, ellagic acid, piperine, costunolide and dehydrocostus lactone in Liuwei Muxiang capsules.

In this study, a sensitive high-performance liquid chromatography detector was established and validated for the simultaneous determination of geniposide, ellagic acid, piperine, costunolide and dehydrocostuslactone in Liuwei Muxiang Capsules. The analysis was achieved on CHANIN 100-5-C18-H column (5µm, 250 mm×4.6 mm) with the temperature of 30oC. Gradient elution was applied using 0.1% phosphoric acid solution-methanol-acetonitrile (50:50) as mobile phase at the flow rate of 1.0 mL/min. The determination was performed at the wavelength of 225 nm (detecting geniposide), 254 nm (detecting ellagic acid), 343 nm (detecting piperine) and 225 nm (detecting costunolide and dehydrocostuslactone) along with the sample volume of 10µL. The linear ranges of geniposide, ellagic acid, piperine, costunolide and dehydrocostuslactone demonstrated good linear relationships within their respective determination ranges. The average recoveries were 100.04%, 99.86%, 99.79%, 100.17% and 100.41%, respectively. RSD% was 1.3%, 1.2%, 1.2%, 1.2%, 1.5%, respectively. The developed method was proved to be simple, accurate and sensitive, which can provide a quantitative analysis method for the content determination of geniposide, ellagic acid, piperine, costunolide and dehydrocostuslactone in Liuwei Muxiang capsules.

Determination of rebamipide in human plasma by a validated liquid chromatography-tandem mass spectrometry: Application in pharmacokinetics research.

A new method for the determination of rebamipide in human heparin sodium plasma by LC-MS was established and its methodology was validated. In this method, protein precipitation method was used to pretreat the samples and the rebamipide-d4 isotope of rebamipide was used as the internal standard. In the multi reaction monitoring mode, the electrospray ion source was used as the ionization technolog and LC-MS was used for detection and analysis. The liquid chromatographic conditions were: 00B-4605-AN (Kinetex® XB-C18 100A 50mm × 2.1mm, 5µm); mobile phase A: 0.1% FA and 1 mM NH4FA aqueous solution, mobile phase B: 0.1% FA and 1mM NH4FA 90% ACN solution, flow rate: 0.300mL/min, injection volume: 10uL, column temperature: 30oC, collection time: 3 min, injector temperature control: 5oC. The retention time of rebamipide and rebamipide-d4 were 1.32min and 1.31min, respectively. The lower limit of quantification was 1ng/mL and the calibration map of rebamipide in the concentration range of 1 to 800ng/mL was linear (R2 >0.990, n=11). The CV% values of the inter and intra batch precision of the method were both less than 15.0%. This method has been successfully applied to pharmacokinetic studies to evaluate the main pharmacokinetic parameters of rebamipide.

In Ovo Injection of CHIR-99021 Promotes Feather Follicle Development via Modulating the Wnt Signaling Pathway and Transcriptome in Goose Embryos (Anser cygnoides).

Feather performs important physiological functions in birds, and it is also one of the economic productions in goose farming. Understanding and modulating feather follicle development during embryogenesis are essential for bird biology and the poultry industry. CHIR-99021 is a potent Wnt/ß-catenin signaling pathway activator associated with feather follicle development. In this study, goose embryos (Anser cygnoides) received an in ovo injection of CHIR-9902, which was conducted at the beginning of feather follicle development (E9). The results showed that feather growth and feather follicle development were promoted. The Wnt signaling pathway was activated by the inhibition of GSK-3ß. Transcriptomic analyses showed that the transcription changes were related to translation, metabolism, energy transport, and stress in dorsal tissue of embryos that received CHIR-99021, which might be to adapt and coordinate the promoting effects of CHIR-99021 on feather follicle development. This study suggests that in ovo injection of CHIR-99021 is a potential strategy to improve feather follicle development and feather-related traits for goose farming and provides profiling of the Wnt signaling pathway and transcriptome in dorsal tissue of goose embryos for further understanding of feather follicle development.