Quantitative determination of corosolic acid in rat plasma by LC-MS/MS-ESI: Application to a pharmacokinetic study

A sensitive and robust liquid chromatography-tandem mass spectrometry (lc-ms/ms) method was developed and validated for the determination of corosolic acid (cra) in rat plasma. the plasma samples were prepared by a simple protein precipitation treatment. chromatographic separation was performed on an agela mg-c18 column (50 mm × 4.6 mm; i.d., 5 μm) at 30°c. the mobile phase consisting of methanol-10 mm ammonium acetate–formic acid (80:20:0.1, v/v/v; ph=3.8) was delivered with a flow rate of 0.6 ml/min and a running time of 2.5 min. quantification was performed with positive electrospray ionization (esi) in the multiple-reaction monitoring (mrm) mode at m/z 490 → m/z 205 for cra, and m/z 471 → m/z 203 for teoa (internal standard, is), respectively. linearity was evaluated over the concentration range of 1.00-1000 ng/ml with a lower limit of quantification (lloq) of 1.00 ng/ml. the validated method was successfully applied to the pharmacokinetic study of cra after the drug was orally administered in sprague-dawley rats