A sensitive high performance liquid chromatography-ultraviolet (HPLC-UV) method for the quantitation of -obscurine in rat plasma and its application to pharmacokinetic studies

A simple and sensitive high performance liquid chromatography (HPLC) method for the determination of α-obscurine in rat plasma has been developed and validated. Separation was achieved on Century Sil EPS C18 (5 μm, 200 × 4.6 mm i.d). The mobile phase, water:methanol:triethanol amine (39:61:0.05 v/v/v), was delivered at a flow rate of 1.0 ml/min. The detector was set at 250 nm. No interfering chromatogram peaks in rat blank plasma was observed. The relationship between α-obscurine concentration and peak area ratio of α-obscurine to the internal standard (IS) was linear over the range of 0.354 to 14.16 μg/ml. The intra- and inter-day coefficients of variation were ≤2.6 and ≤3.7%, respectively. The methods of recovery of α-obscurine was 96.03 to 101.6%, and the extraction recovery was 70.81 to 75.27%. α-Obscurine was found to be for at least 24 h at retention time (RT) and 2 weeks at -20°C. The method was applied to a pharmacokinetic study of α-obscurine in rats. This study establishes and validates a determination of rats plasma puerarin in high performance liquid chromatography and. Key words: Lycopodium japonicum Thunb, high performance liquid chromatography-ultraviolet (HPLC-UV), α-obscurine, pharmacokinetics.