A Validated Hplc Method for Estimation of Metoprolol in Human Plasma

A high-performance reversed-phase liquid chromatographic method for quantification of metoprolol tartrate (MT) in human plasma is presented. A C18 column was used with acetonitrile–water–triethylamine 18:81:1 (v/v) as mobile phase and pinacidil monohydrate as internal standard (IS). UV detection was at 275 nm and MT and the IS were detected at retention times of 1.5 and 2.6 min, respectively. The method is sensitive with a limit of quantification of 20 ng mL. The calibration plot for MT in spiked plasma was linear in the concentration range 20–200 ng mL. Within-batch and total accuracy of the method ranged between 99.71% and 101.61%, and within-batch and total precision, expressed as the coefficient of variation, was 0.20–2.13%. Recovery of MT from spiked plasma was 97.00% and the freeze–thaw and bench-top stability of samples ranged from 77.92 to 105.62%. The method can be successfully used for analysis of MT in human plasma during pharmacokinetic studies.