LC-MS/MS determination and pharmacokinetic study of columbianadin in rat plasma after intravenous administration of pure columbianadin.

Background: Columbianadin, one of the active coumarins, is isolated from Radix Angelicae pubescentis which has been used as a traditional Chinese medicine for the treatment of rheumatic diseases for thousands of years. A fast and sensitive method is required for the determination of columbianadin for pharmacokinetic studies. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) method is a preeminent analytical tool for rapid biomedical analysis.

Results: A sensitive LC-MS/MS method has been validated to determine the concentration of columbianadin in rat plasma after intravenous administration of columbianadin (1, 2.5 and 5 mg kg(-1)). Liquid-liquid extraction was used to extract columbianadin from the rat plasma. Bergapten was selected as an internal standard (IS). The separations were performed on an Eclipse plus C18 column (4.6 × 100 mm, 1.8 μm) with ammonium acetate aqueous solution (1 mmol L(-1)) and acetonitrile as the mobile phase. The flow rate was set at 0.300 mL min(-1). Quantification was performed using multiple reaction monitoring (MRM) mode to monitor transitions of m/z 329.3 → 229.3 for columbianadin and m/z 217.2 → 202.2 for IS at positive ionization mode. The calibration curve was linear over the concentration range of 4-20000 ng mL(-1) with a correlation coefficient (r) of 0.996 or better. The precision of intra- and inter-batch assays ranged from 4.02 to 7.33% and accuracies determined at three concentrations ranged between 91.9% and 106%. The lower limit of quantification was about 4 ng mL(-1).

Conclusion: The proposed LC-MS/MS method is simple, rapid and highly sensitive so that it could be used to evaluate pharmacokinetic properties of columbianadin in rat plasma after intravenous administration.