title: Determination of lafutidine in human plasma by high-performance liquid chromatography-electrospray ionization mass spectrometry: application to a bioequivalence study.
abstract: A rapid, sensitive and specific high-performance liquid chromatography-electrospray ionization mass spectrometry (LC/ESI-MS) method was developed and validated for the first time to determine the concentration of lafutidine in human plasma. After the addition of diazepam (the internal standard, IS) and 1 M sodium hydroxide solution to 0.5-ml plasma sample, lafutidine was extracted from plasma with n-hexane : isopropanol (95 : 5, v/v). The organic layer was evaporated and the residue was redissolved in 200-microl mobile phase. The analyte was chromatographically separated on a prepacked Shimadzu Shim-pack VP-ODS C(18) column (250 x 2.0 mm i.d.) using a mixture of methanol-water (20 mM CH(3)COONH(4)) = 80 : 20 (v/v) as mobile phase. Detection was performed on a single quadrupole mass spectrometer using an electrospray ionization interface and the selected-ion monitoring (SIM) mode. The method showed excellent linearity (r = 0.9993) over the concentration range of 5-400 ng/ml and had good accuracy and precision. The within- and between-batch precisions were within 10% relative standard deviation. The limit of detection was 1 ng/ml. The validated LC/ESI-MS method has been successfully applied to the bioequivalence study of lafutidine in 24 healthy male Chinese volunteers.
authors.affiliation: Center for Instrumental Analysis, China Pharmaceutical University, Nanjing 210009, P. R. China.
authors.forename: Lili
authors.initials: L
authors.lastname: Wu
authors.forename: Zunjian
authors.initials: Z
authors.lastname: Zhang
authors.forename: Yuan
authors.initials: Y
authors.lastname: Tian
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Fengguo
authors.initials: F
authors.lastname: Xu
authors.forename: Yun
authors.initials: Y
authors.lastname: Chen
authors.forename: Huilin
authors.initials: H
authors.lastname: Wei
mesh_terms: D000081:Acetamides / Q000097:blood* / Q000493:pharmacokinetics; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004355:Drug Stability; D006635:Histamine H2 Antagonists / Q000097:blood / Q000493:pharmacokinetics; D006801:Humans; D008297:Male; D010880:Piperidines / Q000097:blood* / Q000493:pharmacokinetics; D011725:Pyridines / Q000097:blood* / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013810:Therapeutic Equivalency
chemical_list: D000081:Acetamides; D006635:Histamine H2 Antagonists; D010880:Piperidines; D011725:Pyridines; C076948:lafutidine