Abstract

For the first time, a rapid and specific reversed phase-high performance liquid chromatography-ultraviolet (RP-HPLC-UV) method was developed for the analysis of polyphyllin I and polyphyllin II in beagle dog plasma. The method was applied to study the pharmacokinetics of Rhizoma paridis capsule containing polyphyllin I and polyphyllin II. The analysis was carried out on a Diamonsil C₁₈ (2) reversed-phase column (250 ´ 4.60 mm, 5 μm) by isocratic elution with acetonitrile and 0.1% phosphoric acid (50: 50, v/v). The flow rate was 1.00 ml/min and the detection wavelength was set at 203 nm. Linear responses were obtained for polyphyllin I ranging from 2 to 300 µg/ml. The intra-and inter-day precisions (RSDs) were less than 9.23 and 9.24% with the accuracy (%) ranging from 87.65 to 107.25%. The extraction recovery ranged from 85.07 to 91.82% with RSD less than 5.55%. Stability studies showed that polyphyllin I and polyphyllin II were stable in preparation and analytical process. The results indicated that the validated method was successfully used to determine the concentration-time profiles of polyphyllin I and polyphyllin II.

Key words: Polyphyllin I, polyphyllin II, pharmacokinetics, reversed phase-high performance liquid chromatography (RP-HPLC), beagle dog plasma.