Pharmacokinetic analysis of glaucocalyxin A in rat plasma by liquid-liquid extraction and HPLC.

A validated HPLC method is described for determination of glaucocalyxin A in rat plasma using liquid-liquid extraction and UV absorbance detection. The extraction recovery of glaucocalyxin A ranged from 81.72 % to 79.25 %, the linear range was 0.2-10 microg/mL, and R was 0.9984. A pharmacokinetic analysis of glaucocalyxin A after intravenous administration in rats revealed that glaucocalyxin A followed a two-compartment open model. The values of t (1/2alpha) and t (1/2beta) were 4.327 min and 28.56 min, respectively, and the area under the plasma concentration-time curve (AUC) was 222.744 microg x min x mL (-1). The method developed was simple, rapid and specific, and an accurate way of investigating the pharmacokinetics of a diterpenoid in plasma.