“…13 Consequently, the CYP2D6 oxidation phenotype and stereoselectivity represent the major factors that yield interindividual variability in the metabolism of metoprolol. 4,7,9 Metoprolol enantiomers have been separated by direct analysis using four types of chromatographic columns based on chiral stationary phases: ␣ 1 -acid glycoprotein, [14][15][16][17] cellulose tris(3,5-dimethylphenylcarbamate), [18][19][20][21][22][23][24][25][26] amylose tris(3,5-dimethylphenylcarbamate), 8,24 and the antibiotic Teicoplanin. 27 Schuster et al 28 used 2,3,4,5-tetra-Oacetyl--d-glucopyranosyl isothiocianate (GITC) as derivatization reagent to assay metoprolol enantiomers and ␣-hydroxymetoprolol diastereomers indirectly.…”