Quantitation of talinolol in rat plasma by LC-MS-MS.

The aim of this study was to develop and validate an assay based on liquid chromatography-tandem mass spectrometry to quantitate talinolol in rat plasma. After a simple protein precipitation step, separation was performed by reversed-phase liquid chromatography using gradient elution with acetonitrile-water-formic acid. Electrospray ionization in the positive ion mode with multiple reaction monitoring was used to analyze talinolol employing propranolol as internal standard. The calibration curve for talinolol was linear over the concentration range 1-250 ng/mL with a correlation coefficient > 0.995. The method was sensitive (limit of quantitation, 1 ng/mL) and had acceptable accuracy (85-115% of true values) and precision (intra- and inter-assay CV < 15%). Recovery of talinolol at concentrations of 1, 25, and 250 ng/mL was >78%. The method was successfully applied to the determination of the oral pharmacokinetics of talinolol in rat.