RESUMO
Objective: To establish a UPLC-MS/MS method for simultaneous determination of sophoraflavanone G (SFG), kurarinone (Kur), and isoxanthohumol (Iso) in rat plasma using rutin as the internal standard (IS), and to study the pharmacokinetic parameters of total flavonoids (TF) from Sophora flavescens and TF self-microemulsion drug delivery system (TF-SMEDDS) in rats. Methods: Analysis was carried out on an ACQUITY UPLC® HSS T3 C18 column using acetonitrile-0.1% formic acid in water as the mobile phase at a flow rate of 0.2 mL/min. The plasma samples were prepared by liquid-liquid extraction with ethyl acetate. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring with an electro-spray ionization source in negative ionization mode. All statistical analysis was performed using DAS 2.0 software package. Results: The calibration curves of Kur, SFG, and Iso exhibited good linearity (r2 > 0.995 9) over the range of (0.02-1 600.00), (0.015-1 200.000), and (0.01-800.00) ng/mL, respectively. Precision, accuracy, average extraction recovery, and matrix effects were all in line with biological sample analysis requirements. The pharmacokinetic parameters of Kur, SFG, and Iso from TF were as follows: t1/2z (7.04 ±2.46), (4.54 ± 2.13), (4.73 ± 1.67) h, and AUC0-∞ (3 469.57 ± 555.37), (2 524.48 ± 425.83), (1 006.47 ± 85.46) ng∙h/mL. The pharmacokinetic parameters of Kur, SFG, and Iso from TF-SMEDDS were as follows: t1/2z (13.10 ± 2.67), (11.47 ± 4.17), and (12.67 ± 4.97) h, and AUC0-∞ (13 002.49 ± 2 498.09), (8 070.80 ± 2 264.62), (3 918.85 ± 429.76) ng∙h/mL. The relative bioavailabilities of Kur, SFG, and Iso in TF-SMEDDS were approximately 374.76%, 319.70%, and 389.37%, respectively. Conclusion: The UPLC-MS/MS method can be used to study the pharmacokinetics of three components in S. flavescens in rats. The bioavailability of TF-SMEDDS in rats was significantly increased.