title: Rapid and highly sensitive method for the determination of verapamil, [2H7]verapamil and metabolites in biological fluids by liquid chromatography-mass spectrometry.
abstract: A rapid and highly sensitive method for the determination of verapamil [2,8-bis-(3,4-dimethoxyphenyl)-6-methyl-2-isopropyl-6-azaoctanitrile+ ++] and [2H7]verapamil and their primary metabolites D-617 [2-(3,4-dimethoxyphenyl)-5-methylamino-2-isopropylvaleronitrile], D-703 [2-(4-hydroxy-3-methoxyphenyl)-8-(3,4-dimethoxy-phenyl)-6-methyl-2-iso-p ropyl-6-azaoctanitrile], D-702 [2-(3,4-dimethoxy-phenyl)-8-(4-hydroxy-3-methoxyphenyl)-6-methyl-2-isopr opyl-6-azaoctanitrile], norverapamil [2,8-bis-(3,4-dimethoxyphenyl)-2-isopropyl-6-azaoctanitrile] and secondary metabolites D-620 [2-(3,4-dimethoxyphenyl)-5-amino-2-isopropylvaleronitrile], D-717 [2-(4-hydroxy-3-methoxyphenyl)-5-amino-2-isopropylvaleronitrile], and D-715 [2-(4-hydroxy-3-methoxyphenyl)-8-(3,4-dimethoxy-phenyl)-2-isopropyl-6-++ +azaoctanitrile] has been developed using high-performance liquid chromatography-electrospray mass spectrometry. D-832, the gallopamil analogue of D-617 and [2H3]norverapamil were used as internal standards. The analytes were extracted automatically from plasma and intestinal perfusate using end-capped CN- and C2 solid-phase extraction cartridges. Separation of the eight analytes was achieved on a LUNA C8 analytical column (150x2 mm I.D., 5 microm particle size) with 5 mM ammonium acetate-acetonitrile as the mobile phase run with a gradient from 70:30 to 40:60 and run times of 15 min. With the mass spectrometer operated in the selected-ion monitoring mode, the limits of quantification in plasma and intestinal perfusate were 1 pmol/ml for D-620, D-617, D-702, D-703, norverapamil, verapamil, and [2H7]verapamil and 2.5 pmol/ml for D-717 and D-715 using a sample size of 1 ml plasma and intestinal perfusate. The method described was successfully applied to the determination of verapamil, [2H7]verapamil and their metabolites in human plasma and intestinal fluid in pharmacokinetic studies.
authors.affiliation: Dr. Margarete Fischer-Bosch-Institut für Klinische Pharmakologie, Stuttgart, Germany.
authors.forename: O
authors.initials: O
authors.lastname: von Richter
authors.forename: M
authors.initials: M
authors.lastname: Eichelbaum
authors.forename: F
authors.initials: F
authors.lastname: Schönberger
authors.forename: U
authors.initials: U
authors.lastname: Hofmann
mesh_terms: D001826:Body Fluids / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003903:Deuterium; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism; D013058:Mass Spectrometry / Q000379:methods*; D011786:Quality Control; D012680:Sensitivity and Specificity; D014700:Verapamil / Q000032:analysis* / Q000097:blood / Q000378:metabolism*
chemical_list: D003903:Deuterium; D014700:Verapamil