Čes. slov. farm. 2008, 57(6):254-259

Determination of metoprolol and its metabolite α-hydroxymetoprolol in serum by HPLC method with fluorescence detection

I. Peřinová^*, J. Ďuricová, H. Brozmanová, I. Kacířová, M. Grundmann

Ostravská univerzita Ostrava, Ústav klinické farmakologie FN a Zdravotně-sociální fakulty

High-performance liquid chromatography method has been developed with a view of its future use in the phenotyping of CYP2D6 enzyme by metoprolol as a probe drug. Metoprolol, α-hydroxymetoprolol and the internal standard nadolol were extracted from serum with dichloromethane alkalinized with 1 mol/l NaOH. Chromatographic separations were performed on the reversed-phase column SupercosilTM LC-18 (15 cm × 3 mm, 5 μm) with the mobile phase containing acetonitril : methanol : water : triethylamine (15 : 5 : 80 : 0.1, pH 3.0) at a flow rate of 0.7 ml/min. Fluorescence detection (FL) was made at 230 nm (excitation) and 300 nm (emission). The total analysis time was 12 min. The retention time for α-hydroxymetoprolol, nadolol and metoprolol were 2.04, 3.02 and 9.04 min, respectively. The intra-assay and inter-assay precisions (coefficients of variation) were less than 7.2 %, and recovery values were found to be within 98.2-103.0 %. The calibration curve of the method was linear over a concentration range of 25-500 ng/ml (r = 0.999) for both compounds. The limit of detection was 5 ng/ml and the limit of quantification was 25 ng/ml for both metoprolol and α-hydroxymetoprolol. The reported method could be suitable for measurements of metoprolol and α-hydroxymetoprolol in serum from patients with hypertension, IHD and other illnesses.

Keywords: phenotyping CYP2D6; metoprolol; α-hydroxymetoprolol; HPLC-FL

Received: August 25, 2008; Accepted: October 10, 2008; Published: June 1, 2008  Show citation