Validated capillary electrophoresis assay for the simultaneous enantioselective determination of propafenone and its major metabolites in biological samples.
A robust, inexpensive, and fully validated CE method for the simultaneous determination of the enantiomers of propafenone (PPF), 5-hydroxy-propafenone (5OH-PPF) and N-despropyl-propafenone (NOR-PPF) in serum and in in vitro media is described. It is based upon liquid-liquid extraction at alkaline pH followed by analysis of the reconstituted extract by CE in presence of a pH 2.0 running buffer composed of 100 mM sodium phosphate, 19% methanol, and 0.6% highly sulfated beta-CD. For each compound, the S-enantiomers are shown to migrate ahead of their antipodes, and the overall run time is about 30 min. Enantiomer levels between 25 and 1000 ng/mL provide linear calibration graphs, and the LOD for all enantiomers is between 10 and 12 ng/mL. The assay is shown to be suitable for the determination of the enantiomers of PPF and its metabolites in in vitro incubations comprising human liver microsomes or single CYP450 enzymes (SUPERSOMES). Incubations with CYP2D6 SUPERSOMES revealed, for the first time, the simultaneous formation of the enantiomers of 5OH-PPF and NOR-PPF with that enzyme. CE data can be used for the evaluation of the enzymatic N-dealkylation and hydroxylation rates.
Department of Clinical Pharmacology, University of Bern, Bern, Switzerland.
Minoo
M
Afshar
Wolfgang
W
Thormann
D000889:Anti-Arrhythmia Agents / Q000032:analysis; D019389:Cytochrome P-450 CYP2D6 / Q000378:metabolism; D051544:Cytochrome P-450 CYP3A; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D019075:Electrophoresis, Capillary / Q000379:methods*; D006801:Humans; D008862:Microsomes, Liver / Q000378:metabolism; D011405:Propafenone / Q000031:analogs & derivatives / Q000032:analysis* / Q000097:blood / Q000378:metabolism*; D015203:Reproducibility of Results; D013237:Stereoisomerism
D000889:Anti-Arrhythmia Agents; D011405:Propafenone; C044307:5-hydroxypropafenone; D003577:Cytochrome P-450 Enzyme System; D019389:Cytochrome P-450 CYP2D6; D051544:Cytochrome P-450 CYP3A; C510163:CYP3A4 protein, human; C045806:N-depropylpropafenone