Pharmacokinetic profile and bioavailability assessment of rubusoside in mouse plasma utilizing UPLC-MS/MS analysis

The ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) technique was utilized to detect rubusoside in mouse plasma and evaluate its pharmacokinetic behavior following oral administration at doses of 10 mg/kg and 20 mg/kg, as well as intravenous administration at 10 mg/kg. Plasma samples were prepared using a protein precipitation method employing acetonitrile as the precipitating agent and isoscoparin as the internal standard (IS). Chromatographic separation was performed on a UPLC high strength silica (HSS) T3 column under gradient elution conditions, using acetonitrile and 0.1 % formic acid in water as the mobile phase system. The calibration curve for rubusoside demonstrated excellent linearity across a concentration range of 3.5 to 1120 ng/mL. Both intra-day and inter-day precision values remained below 7 %, with accuracy ranging from 92.3 % to 108.1 %. Matrix effects were consistently within the range of 107.1 % to 110.0 %, and the recovery rate exceeded 74.2 %. Following oral administration, the absolute bioavailability of rubusoside was determined to be 1.00 % and 0.98 % at doses of 10 mg/kg and 20 mg/kg, respectively. These findings confirm that the developed UPLC-MS/MS method effectively supports the pharmacokinetic evaluation of rubusoside.