Miniature mass spectrometer-based point-of-care assay for quantification of metformin and sitagliptin in human blood and urine.

Metformin (MET) and sitagliptin (STG) are widely used as the first-line and long-term oral hypoglycemic agents for managing type 2 diabetes mellitus (T2DM). However, the current lack of convenient and rapid measurement methods poses a challenge for individualized management. This study developed a point-of-care (POC) assay method utilizing a miniature mass spectrometer, enabling rapid and accurate quantification of MET and STG concentrations in human blood and urine. By combining the miniature mass spectrometer with paper spray ionization, this method simplifies the process into three to four steps, requires minimal amounts of bodily fluids (50 µL of blood and 2 µL of urine), and is able to obtain quantification results within approximately 2 min. Stable isotope-labeled internal standards were employed to enhance the accuracy and stability of measurement. The MS/MS responses exhibited good linear relationship with concentration, with relative standard deviations (RSDs) below 25%. It has the potential to provide immediate treatment feedback and decision support for patients and healthcare professionals in clinical practice.

[Quantification of sitagliptin in human plasma and urine by LC-MS/MS method and its application].

A rapid and sensitive liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) method for quantification of sitagliptin in human plasma and urine had been developed. This method was applied to the pharmacokinetics study of sitagliptin tablet after single- and multiple-dosing in Chinese population. Plasma samples were prepared by a liquid-liquid extracted method, and urine samples were diluted. Compounds were analyzed by multiple reaction monitoring (MRM) mode with a electrospray ionization (ESI) interface. Mobile phase consisted of methanol and water (85 : 15, v/v). The linear concentration range of calibration curve was 0.5-1 000 ng.mL-1. and 0.2-100 µg.mL , intra-run/between-run accuracy was 98.98%-103.69% and 97.63%-102.29%, intra-run/between-run precision was <5.51% and 4.26% for plasma and urine sample, respectively. The stability of sitagliptin stock solution was tested for 55 days at -30 °C. Sitagliptin was stable when stored under the following conditions: 24 hours in the autosampler after sample preparation; 24 hours at room temperature, after 3 freeze and thaw cycles (from -30 °C to room temperature), 40 days at -30 °C for plasma and urine samples. The absolute recovery in plasma was 71.1%, and no matrix effect was founded. This method was proved simple, specific, sensitive, rapid and suitable for pharmacokinetics study of sitagliptin in human being.