Determination of metoprolol and its alpha-hydroxide metabolite in serum by reversed-phase high-performance liquid chromatography.
A high-performance liquid chromatographic (HPLC) method for the simultaneous quantitation of metoprolol and alpha-hydroxymetoprolol concentrations in serum is developed. Analysis is performed on a C18 column using a 70:30 mixture of two solutions, A and B respectively. Solution A is 1 L of a 1% acetic acid solution with 25 mL of 0.005 M 1-heptanesulfonic acid. Solution B is 1 L of acetonitrile with 25 mL of 0.005 M 1-heptanesulfonic acid. Column effluent is monitored by fluorescence detection at an excitation wavelength of 225 nm. A 320-nm band pass filter is employed. The limit of sensitivity is approximately 2 ng/mL for both compounds. No potential sources of interference are identified. A coefficient of variation of less than 10% is observed on replicate determinations at 10 ng/mL for both compounds and at 300 and 180 ng/mL for metoprolol and alpha-hydroxymetoprolol, respectively. The method has the advantages of complete resolution of the metabolite of metoprolol, a high degree of reproducibility, adequate sensitivity, and an easily accessible internal standard.
Rutledge
D R
DR
Department of Pharmacy Practice, Wayne State University, College of Pharmacy, Detroit, Michigan 48202.
Garrick
C
C
D002851:Chromatography, High Pressure Liquid; D006801:Humans; D007202:Indicators and Reagents; D007275:Injections, Intravenous; D008790:Metoprolol / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics / Q000031:analogs & derivatives
D007202:Indicators and Reagents; C029504:alpha-hydroxymetoprolol; D008790:Metoprolol