title: An LC method for quantifying bepridil in human plasma using 1-naphthol as the internal standard.
abstract: A modified method for the quantitative determination of bepridil hydrochloride in human plasma is described. This method is unrelated to chemical methods currently in use. The mobile phase is 50 mM phosphate buffer (pH3.0)-methanol-acetonitrile-triethylamine (57:3:40:1, v/v), and the samples are fractionated on a C8-3 column (150 × 4.6 mm, 5 μm) using a flow rate of 0.9 mL/min. Bepridil was detected by UV spectroscopy at 254 nm. The retention times of bepridil and 1-naphthol were 12.6 min and 7.5 min, respectively; there was no interference originating from human plasma. We confirmed that the bepridil and 1-naphthol peaks were not influenced by the presence of 32 commercial medicines frequently co-administered with bepridil. Additionally, the concentration of bepridil in the plasma of five patients treated with bepridil for atrial fibrillation was measured. These samples were collected just before each dosage of bepridil. Their rhythm and rate control were well maintained. Trough concentrations ranged from 233.9 to 347.4 ng/mL, similar to previously reported values.
authors.affiliation: Department of Practical Pharmacy, Faculty of Pharmaceutical Science, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Tobetsu Hokkaido 061-0293, Japan.
authors.forename: Kumiko
authors.initials: K
authors.lastname: Noda
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Narayama
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Goto
authors.forename: Michiya
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kuronuma
authors.forename: Shinji
authors.initials: S
authors.lastname: Iwai
authors.forename: Katsumi
authors.initials: K
authors.lastname: Itoh
authors.forename: Noriyoshi
authors.initials: N
authors.lastname: Katoh
authors.forename: Koji
authors.initials: K
authors.lastname: Tadano
mesh_terms: D000889:Anti-Arrhythmia Agents / Q000097:blood*; D001281:Atrial Fibrillation / Q000097:blood / Q000188:drug therapy; D015764:Bepridil / Q000097:blood*; D002851:Chromatography, High Pressure Liquid / Q000379:methods* / Q000592:standards; D006801:Humans; D009284:Naphthols / Q000032:analysis*; D012015:Reference Standards
chemical_list: D000889:Anti-Arrhythmia Agents; D009284:Naphthols; C029350:1-naphthol; D015764:Bepridil