HPLC method for the simultaneous determination of four compounds in rat plasma after intravenous administration of Portulaca oleracea L. extract

the objective of the present study was to develop a simple and selective hplc method for the simultaneous determination of hesperidin (hp), caffeic acid (ca), ferulic acid (fa) and p-coumaric acid (p-ca) in rat plasma after intravenous administration of portulaca oleracea l. extract (poe). with the hyperoside as the internal standard, the sample pretreatment procedure involved simple single-step extraction with methanol of 0.2 ml plasma. the mobile phase consisted of methanol-acetonitrile-tetrahydrofuran-0.5% glacial acetic acid (5:3:18:74, v/v/v/v). the calibration curves were linear over the range of 0.1-25 μg ml-1, 0.1-25 μg ml-1, 0.1-25 μg ml-1and 0.015-3 μg ml-1 for hp, ca, fa and p-ca, respectively. the method developed was suitable for the pharmacokinetic study of hp, ca, fa and p-ca in rats after intravenous administration of poe.