To develop a high performance liquid chromatography-mass spectrometry (HPLC-MS/MS) method for the determination of vildagliptin in human anticoagulant plasma with ethylenediamine tetra acetic acid and apply it to the study of pharmacokinetics.
13C-15N-vildagliptin was used as internal standard (IS). After extraction from human plasma by protein precipitation with acetonitrile, all components were separated by a Hypurity C18 column (150 mm×2.1 mm, 5 μm), using a gradient elution procedure consisting of methanol and 5 mmol·L-1 ammonium formate at a flow rate of 0.5 mL·min-1, and the column temperature was 40 ℃. Injection volume was just 2 μL. Positive electrospray ionization was performed using multiple reaction monitoring (MRM) with transitions of m/z 304.3→154.2 for vildagliptin and m/z 310.3→160.3 for internal standard. Specificity, standard curve, lower limit of quantification, precision, recovery, matrix effect and stability were examined. Then this method was used to determine the plasma concentration of veragliptin in healthy subjects.
The calibration curve of vildagliptin in human plasma was linear over the concentration range of 1.11 to 534.0 ng·mL-1. The lower limit of quantitation was 1.11 ng·mL-1. The intra-and inter-day precisions at four quality control levels were within 0.9%-8.5%, and the accuracy was within 99.8%-109.3%. The data of short-term stability at room temperature displayed that the accuracy percentage of LQC samples was 92.0% for 0.5 h exposure, 87.6% for 1 h exposure, 71.2% for 2 h exposure. These of LQC samples chilled on ice was 102.0% for 0.5 h exposure, 94.5% for 1 h exposure, 86.6% for 2 h exposure. These results showed a phenomenon that there was a possible degradation of vildagliptin in plasma. The results of extraction recovery and matrix effect and other stability met the requirements of biological sample analysis. The pharmacokinetic study results of 8 healthy subjects showed that t1/2 was (1.49±0.37) h, tmax was (2.06±1.11) h, Cmax was (290.94±100.36) ng·mL-1, AUC0-24 h was (1 343.46±186.89) ng·h·mL-1, AUC0-∞ was (1 351.31±188.79) ng·h·mL-1.
This method is easy to operate, has high specificity, and sensitivity. It has been successfully applied to the pharmacokinetic study of 8 healthy subjects after oral administration of 50 mg vigagliptin tablets on an empty stomach. Therefore, it can be used as a reliable detection method for human pharmacokinetic research and therapeutic drug monitoring.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |