Preparation Process, Quality Evaluation and Antipyretic Pharmacodynamics of Bupleurum Nanoemulsion

OBJECTIVE  To screen the prescription and preparation method of Bupleurum nanoemulsion, and evaluate its quality, study the antipyretic effect.

METHODS  The emulsifier and co-emulsifier of the nanoemulsion were preliminarily screened, and then the prescription was screened by pseudo-ternary phase diagram. The quality evaluation of the appearance, particle size distribution, structure type, stability and content of the prepared Bupleurum nanoemulsion was performed. Wistar rats were further randomly divided into blank control group, model control group, positive control group(aspirin group), Bupleurum nanoemulsion high-dose, medium-dose and low-dose groups(18.00, 9.00, 3.00 g·kg⁻¹). Except for the blank control group, the pathological model of fever rats was prepared in the other groups. According to the scheduled experimental requirements, rats in each group were given the corresponding drugs. And the temperature changes of rats in each group were recorded at 0.5, 1, 1.5, 2, 3 h to observe the antipyretic effect of Bupleurum nanoemulsion.

RESULTS  The best prescription of Bupleurum nanoemulsion: Tween-80 6 g and n-butanol 3 g, Bupleurum extract dissolved in pure water as water phase 20 mL, Bupleurum oil as oil phase 2 g. At room temperature, the Bupleurum nanoemulsion was a yellow-brown clear and transparent liquid, O/W nanoemulsion, with an average particle size of (77.21±3.66)nm, polydispersity index of 0.28±0.04, Zeta potential of (–18.81±1.42)mV, and saikosaponin content of 3.071 mg·mL⁻¹, with good stability. In animal experiments, compared with the model control group, the rectal temperature of aspirin group and Bupleurum nanoemulsion high-dose group was significantly lower after the first administration(P<0.01), the rectal temperature of Bupleurum nanoemulsion middle-dose group was significantly lower after the first administration 2, 3 h(P<0.01).

CONCLUSION  The Bupleurum nanoemulsion is transparent and stable, and it has good antipyretic effect on fever rat model.