Development and validation of an UPLC-PDA method for the determination of corilagin in rat plasma and its application to pharmacokinetic study

Corilagin, which was isolated from several medical herbs, has been reported to exert many pharmacological activities. A simple and rapid liquid ultra-performance liquid chromatography (UPLC) coupled to photodiode array (PDA) method has been developed to quantify corilagin in rat plasma. In this study, plasma samples were prepared by ethyl acetate extraction. Separation was performed on a HSS T3 (100 mm × 2.1 mm, 1.8 μm) column by using a mobile phase of acetonitrile and water with 0.1% trifluoroacetic acid (v/v). Corilagin and internal standard epicatechin were detected at a wavelength of 266 nm. The calibration curve was linear (r > 0.998) over a concentration range of 0.2 μg/mL to 20 μg/mL with a lower quantification limit of 0.2 μg/mL. Both intra and inter-day precision values were within 5.7% and extraction recovery were greater than 81.0%. Stability tests showed that corilagin and IS remained stable during the analytical procedure. The validated UPLC-PDA method was then used to analyze the pharmacokinetics of corilagin administered to rats intravenously (10 mg/kg) or orally (50 mg/kg). Oral bioavailability of corilagin was calculated to be 10.7%, indicating that this component is not suitable for oral administration. The results provide basis for further preclinical studies on corilagin.