Rapid and Sensitive Bioanalytical Method Development and Validation for Quantification of Metoprolol Using LC-MS/MS in Human Plasma

A novel, accurate, simple and selective LC-MS/MS method was developed and validated for the determination of metoprolol in human plasma. Due to structural resemblance Propranolol was selected as internal standard. Anti coagulant used was K2 EDTA. Metoprolol, used in the therapy and management of hypertension, myocardial infraction and other cardio vascular diseases. Liquid - liquid extraction technique with tert-butyl methyl ether was applied for the extraction of analyte from human plasma. Kromasil C18 column (5 mu, 100 x 4.6 mm) with an isocratic mobile phase of 5mM Ammonium Formate pH 3.5 and Acetonitrile (15:85 V/V) was used for the resolution. Sample ionization was done with Electrospray ionization technique in positive ion mode. Selectivity was enhanced by tandem mass spectrometric analysis via two multiple reaction monitoring (MRM) transitions, m/z 268.15 -> 415.90 for metoprolol and 260.17 -> 415.90 for Propranolol respectively. The linearity of the method was established over a concentration range of 1.505 - 538.254 ng/mL, in human plasma, with the precision and accuracy ranging from 4.67 to 7.41% and 90.66 to 98.15% respectively. The stability of the analyte was evaluated in plasma under different storage conditions.