Authors:Aixia Han, Guanyang Lin, Jinzhang Cai, Qing Wu, Peiwu Geng, Jianshe Ma, Xianqin Wang, and Chongliang Lin
An ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) method was established to determine hirsutine and hirsuteine in rat plasma. Pharmacokinetics of hirsutine and hirsuteine in rats after intravenous or oral administration has been investigated using this developed UPLC–MS/MS method, and bioavailability of the two drugs was calculated. Diazepam was used as internal standard, and UPLC BEH column (2.1 mm × 50 mm, 1.7 μm) was used at temperature of 40 °C. The mobile phase was composed of acetonitrile and water (containing 0.1% formic acid) at a gradient elution flow rate of 0.4 mL/min. Nitrogen was used as desolvation gas (800 L/h) and conical gas (50 L/h). The multiple reaction monitoring (MRM) model was applied to quantitatively analyze hirsutine m/z 369 → 226, hirsuteine m/z 367 → 169.9, and diazepam (internal standard) m/z 285.1 → 193.3. Rat plasma samples were deproteinized using acetonitrile prior to UPLC–MS/MS analysis. Within the concentration range of 1–200 ng/mL, the linearity of hirsutine and hirsuteine in plasma was good (r > 0.995), and the lower limit of quantitation was 1 ng/mL. Relative standard deviations of intra-day precision for hirsutine and hirsuteine were ≤6.1% and ≤5.9%, respectively, and those of inter-day precision were ≤6% and ≤7.7%. Accuracy for hirsutine and hirsuteine ranged between 92.3% and 104.8%. Bioavailability of hirsutine and hirsuteine was 4.4% and 8.2%, respectively. The method is sensitive and fast with good selectivity and was successfully applied in the pharmacokinetic studies after intravenous and oral administration of hirsutine and hirsuteine.
Authors:Chongliang Lin, Dezhen Song, Haodong Jiang, Lvqi Luo, Xi Bao, Xiaomin Yu, Jianshe Ma, Xianqin Wang, and Xiajuan Jiang
Eugenitin is a non-volatile chromone derivative which is always found in dried flower buds of Syzygium aromaticum L. (Merr.) & L.M. Perry. Until now, there were no reports about the pharmacokinetics of eugenitin in biological fluids. A UPLC-MS/MS method developed to determine eugenitin in mouse blood. The blood samples were prepared by protein precipitation with acetonitrile. Chrysin (internal standard, IS) and eugenitin were gradient eluted by mobile phase of acetonitrile and water (0.1% formic acid) in a BEH C18 column. The multiple reaction monitoring (MRM) of m/z 221.1→206.0 for eugenitin and m/z 255.1→152.9 for IS with an electrospray ionization (ESI) source was used for quantitative detection. The calibration curve ranged from 0.5 to 500 ng/mL (r > 0.995). The accuracy ranged from 98 to 113%, the precision was less than 12%, and the matrix effect was between 86 and 94%, the recovery was better than 81%. The developed method was successfully used for pharmacokinetics of eugenitin in mice after intravenous (5 mg/kg) and oral (20 mg/kg) administration, and the absolute availability of eugenitin was 12%.
Authors:Jinzhao Yang, Huamin Liu, Yuan Cai, Yazhen Wu, Xiaoxin Xu, Xianqin Wang, and Chongliang Lin
Twelve Sprague-Dawley rats were randomly divided into two groups: Citrus suavissima Hort. ex Tanaka group and control group (n = 6). The rats in Citrus suavissima Hort. ex Tanaka group were given Citrus suavissima Hort. ex Tanaka juices (1 mL/100 g) by oral administration each day, continued for 14 days; the rats in control group were given Stroke-physiological saline solution (1 mL/100 g) by oral administration each day, continued for 14 days. The rats of these two groups were given a single oral administration of erlotinib (20 mg/kg) on the 15th day. After blood sampling at different time points and processing, the concentrations of erlotinib in rat plasma were determined by the established ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method. Chromatographic separation was achieved using a UPLC BEH C18 column (2.1 mm × 50 mm, 1.7 μm) with erlotinib-d6 as an internal standard (IS). The initial mobile phase consisted of acetonitrile and water (containing 0.1% formic acid) with gradient elution. Multiple reaction monitoring (MRM) modes were utilized to conduct quantitative analysis. The sensitive, rapid and selective UPLC-MS/MS method was successfully applied to analyse the effect of Citrus suavissima Hort. ex Tanaka on pharmacokinetics of erlotinib in rat plasma. There were no significant differences in AUC(0−t), t1/2, Tmax, CL, Cmax between the two groups (P > 0.05). While MRT(0−t) was decreased (P < 0.05) in Citrus suavissima Hort. ex Tanaka group, compared to the control group. It showed that Citrus suavissima Hort. ex Tanaka could not affect the metabolism of erlotinib.
Authors:Jianbo Li, Zheng Yu, Cheng Han, Zhening Wang, Yujie Hu, Congcong Wen, and Chongliang Lin
In this study, we used UPLC–MS/MS to determine diosmetin-7-o-β-d-glucoside in rat plasma and investigated its pharmacokinetics in rats. Six rats were given diosmetin-7-o-β-d-glucoside (5 mg/kg) by intravenous (i.v.) administration. The blood (150 μL) was withdrawn from the caudal vein after administration. Diazepam was used as an internal standard (IS), and a one-step acetonitrile precipitation method was used to process the plasma samples. Chromatographic separation was achieved using a UPLC BEH C18 column using a mobile phase of acetonitrile–0.1% formic acid with gradient elution. Electrospray ionization (ESI) tandem mass spectrometry in multiple reaction monitoring (MRM) mode with positive ionization was applied, 463.1 → 301.0 for diosmetin-7-o-β-d-glucoside, m/z 285.1 → 193.0 for diazepam (IS). Intra-day and inter-day precision of diosmetin-7-o-β-d-glucoside in rat plasma were less than 14%. The method was successfully applied in the pharmacokinetics of diosmetin-7-o-β-d-glucoside in rats after intravenous administration. The t1/2 of diosmetin-7-o-β-d-glucoside is 1.4 ± 0.4 h, which indicates the quick elimination.