Determination of atenolol in human plasma by HPLC with fluorescence detection: validation and application in a pharmacokinetic study.

Atenolol is a cardioselective β1-adrenergic blocker widely used for the treatment of hypertension, angina pectoris and cardiac arrhythmias. A simple, specific, sensitive, precise and accurate high-performance liquid chromatography method with fluorescence detection has been developed and validated for the determination of atenolol in human plasma. After addition of the internal standard, the analytes were extracted by liquid-liquid extraction. The calibration graph for atenolol was linear in a 10-1,000 ng/mL concentration range (r > 0.999), using 0.5-mL plasma samples. The assay precision of the method was less than 6.4%, the assay accuracy ranged between 99.6% and 101.6%, and the absolute recovery of atenolol and internal standard was better than 66.1% and 76.2%, respectively. The method was found to be suitable for the quantification of atenolol in a pharmacokinetic study after a single oral administration of 100 mg atenolol to 18 healthy subjects.