title: Rapid and simultaneous determination of capecitabine and its metabolites in mouse plasma, mouse serum, and in rabbit bile by high-performance liquid chromatography.
abstract: A rapid high-performance liquid chromatography method has been developed for simultaneous determination of capecitabine and its metabolites: 5'-deoxy-5-fluorocytidine (5'-DFCR), 5'-deoxy-5-fluorouridine (5'-DFUR) and 5-fluorouracil (5-FU). 5'-DFCR was synthesized by hydrolyzing capecitabine using commercially available carboxyl esterase (CES) and characterized by NMR, mass spectrometry and elemental analysis. Base-line separations between capecitabine, 5'-DFCR, 5'-DFUR and 5-FU were found with symmetrical peak shapes on a Discovery RP-amide C16 column using 10 mM ammonium acetate at pH 4.0 and methanol as the mobile phase. The retention times of capecitabine, 5'-DFCR, 5'-DFUR and 5-FU were 8.9, 5.0, 5.3 and 3.0 min, respectively. Linear calibration curves were obtained for each compound across a range from 1 to 500 microg ml(-1). The intra- and inter-day relative standard deviations (%RSD) were <5%. A single-step protein precipitation method was employed for separation of the analytes from bio-matrices. Greater than 85% recoveries were obtained for capecitabine, 5'-DFCR, 5'-DFUR and 5-FU from bio-fluids including mouse plasma, mouse serum and rabbit bile.
authors.affiliation: Center for Drug Design and Development, The University of Toledo, Toledo, OH 43606, USA. mugunthu.dhananjeyan@utoledo.edu
authors.forename: Mugunthu R
authors.initials: MR
authors.lastname: Dhananjeyan
authors.forename: Jidong
authors.initials: J
authors.lastname: Liu
authors.forename: Crystal
authors.initials: C
authors.lastname: Bykowski
authors.forename: Jill A
authors.initials: JA
authors.lastname: Trendel
authors.forename: Jeffrey G
authors.initials: JG
authors.lastname: Sarver
authors.forename: Howard
authors.initials: H
authors.lastname: Ando
authors.forename: Paul W
authors.initials: PW
authors.lastname: Erhardt
mesh_terms: D000818:Animals; D001646:Bile / Q000737:chemistry*; D002138:Calibration; D000069287:Capecitabine; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003841:Deoxycytidine / Q000031:analogs & derivatives* / Q000032:analysis / Q000097:blood / Q000378:metabolism; D005467:Floxuridine / Q000032:analysis / Q000097:blood; D005472:Fluorouracil / Q000031:analogs & derivatives* / Q000032:analysis / Q000097:blood / Q000378:metabolism; D051379:Mice; D010949:Plasma / Q000737:chemistry*; D011817:Rabbits; D015203:Reproducibility of Results; D044967:Serum / Q000737:chemistry*
chemical_list: D005467:Floxuridine; D003841:Deoxycytidine; D000069287:Capecitabine; C418208:5'-deoxy-5-fluorocytidine; D005472:Fluorouracil; C025034:doxifluridine