A simple high-performance liquid chromatographic method for the determination of brazilin and its application to a pharmacokinetic study in rats

Ethnopharmacological relevance

Caesalpinia sappan is a medicinal plant native to China popularly used to treat chronic pelvic inflammation, dysmenorrhea and hysteromyoma. Its main bioactive component is brazilin which had presented antibacterial, anti-inflammatory and anti-platelet aggregation activities. To establish a sensitive, selective, reproducible, and accurate high performance liquid chromatographic (HPLC) method for the quantitative determination of brazilin in plasma, and study the pharmacokinetics of brazilin in rats after intravenous administration of brazilin.

Materials and methods

Rats received intravenous injection of 25, 50 and 100 mg/kg of brazilin. Concentrations of brazilin in plasma were determined by HPLC method at different time points and all pharmacokinetic parameters were estimated by non-compartmental analysis with WinNonLin 6.2 software.

Results

After single intravenous doses of 25, 50 and 100 mg/kg brazilin in rats, the main PK parameters were as follows: C_max were 18.1±4.1, 46.7±8.7 and 82.2±9.6 µg/mL; AUC_0–24 were 20.4±4.3, 48.7±6.8 and 90.4±10.3 µg h/mL; and t_1/2 were 5.4±1.5, 5.8±0.9 and 6.2±1.2 h, respectively.

Conclusion

It showed that the brazilin was eliminated moderately in rat by intravenous injection route with t_1/2 of 6 h and showed a dose-dependence profile of C_max and AUC_0–24 at the doses of 25~100 mg/kg of brazilin for injection in rats.