title: Determination of propafenone and its phase I and phase II metabolites in plasma and urine by high-performance liquid chromatography-electrospray ionization mass spectrometry.
abstract: A sensitive method was developed to determine propafenone, 5-hydroxypropafenone, N-despropylpropafenone and propafenone glucuronides in human plasma and urine by HPLC-electrospray ionization mass spectrometry with the respective deuterated analogues as internal standards. The analytes were extracted by a single solid-phase extraction, collecting two fractions, one containing the glucuronides and the other propafenone and the phase I metabolites 5-hydroxypropafenone and N-despropylpropafenone. The mobile phases used for HPLC were: (A) 5 mM ammonium acetate in water and (B) 5 mM ammonium acetate in methanol-tetrahydrofuran (50:50, v/v). Separation of the diastereoisomeric propafenone glucuronides was achieved on a Spherisorb ODS 2 column (150 x 2.0 mm I.D., particle size 5 microm) at a flow-rate of 0.3 ml/min using a linear gradient from 20% B to 50% B in 15 min. For separation of propafenone, 5-hydroxypropafenone and N-desalkylpropafenone a linear gradient from 50% B to 80% B in 10 min was employed. The mass spectrometer was operated in the selected ion monitoring mode using the respective MH+ ions for quantification. The limits of quantification achieved with this method were 10 pmol/ml for propafenone, 5-hydroxypropafenone, R- and S-propafenone glucuronide and 20 pmol/ml for N-desalkylpropafenone using 0.5 ml of plasma. Reproducibility and accuracy was below 12% for each analyte over the whole concentration range measured. The method was applied to a pharmacokinetic study assessing the influence of rifampicin on propafenone disposition.
authors.affiliation: Dr. Margarete Fischer-Bosch-Institut für Klinische Pharmakologie, Stuttgart, Germany. ute.hofmann@ikp-stuttgart.de
authors.forename: U
authors.initials: U
authors.lastname: Hofmann
authors.forename: M
authors.initials: M
authors.lastname: Pecia
authors.forename: G
authors.initials: G
authors.lastname: Heinkele
authors.forename: K
authors.initials: K
authors.lastname: Dilger
authors.forename: H K
authors.initials: HK
authors.lastname: Kroemer
authors.forename: M
authors.initials: M
authors.lastname: Eichelbaum
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D011405:Propafenone / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D011405:Propafenone