[Determination of vitexin in plasma by HPLC-MS/MS method and its pharmacokinetics in rats].

Objective: To establish a HPLC-MS/MS method for the determination of vitexin in rat plasma and its pharmacokinetics.

Methods: The HPLC-MS/MS method used Capcell Pak C18 column (50 mm x 2.0 mm I.

[Effect of verapamil on pharmacokinetics of puerarin in rats].

Objective: To investigate the effect of verapamil on the pharmacokinetics of puerarin in rats.

Method: Puerarin with or without verapamil was administered intravenously or orally to rats. The concentration of puerarin in serum was determined by HPLC.

[Preparation of self-microemulsifying soft capsule and investigation of dissolution for Duyiwei].

Objective: To prepare the self-microemulsifying soft capsule (SMESC) of Duyiwei and investigate its dissolution property.

Methods: Through solubility experiment, self-microemulsification in vitro, drawing phase diagram and investigating the stability of solution, the optimum formulation was determined for Duyiwei. The dissolution of SMESC was measured, taking the commercial capsule as reference.

[Assessment of Pueraria lobata isoflavone with self-microemulsifying drug delivery systems in vitro and in vivo].

Objective: To evaluate the self-microemulsifying ability and dissolution behavior of pueraria lobata isoflavone in vitro and the pharmacokinetic behavior in rats.

Methods: The self-microemulsifying rate was evaluated by the self-microemulsifying time and the self-microemulsifying efficiency was evaluated by the particle size of resultant microemulsions. The plasma concentrations were evaluated by HPLC and dissolution and pharmacokinetic behavior of self-microemulsifying drug delivery systems were evaluated by comparison with commercial tablets.

Pharmacokinetic behaviors and oral bioavailability of oridonin in rat plasma.

Aim: To study the intravenous and oral pharmacokinetic behavior of oridonin and its extent of absolute oral bioavailability in rats.

Methods: Oridonin was administered to rats via iv (5, 10 and 15 mg/kg), po (20, 40 and 80 mg/kg) or ip administration (10 mg/kg). The concentrations of oridonin in rat plasma were determined by a high performance liquid chromatography with electrospray ionization mass spectrometric detection (HPLC/ESI-MS) method and the pharmacokinetic parameters were determined by non-compartmental analysis.