title: High-pressure liquid chromatographic analysis of eflornithine in serum.
abstract: Eflornithine [2-(difluoromethyl)-DL-ornithine monohydrochloride, monohydrate; DFMO] is an ornithine decarboxylase inhibitor used to treat Pneumocystis carinii pneumonia (PCP) in AIDS patients unresponsive or intolerant to conventional drug therapy. A reversed-phase HPLC method utilizing precolumn dansylation is described which permits the analysis of DFMO in serum of AIDS patients in support of pharmacokinetic studies. Norvaline (2-amino valeric acid) was added as the internal standard and the sample was extracted with three portions of ice-cold 80% ethanol. The supernatants were evaporated in a vacuum oven at 50 degrees C, and the residue was dissolved in base and derivatized at 25 degrees C for 4 h in the dark using dansyl chloride in acetone. Dilute base was then added and 25 to 50 microL was injected into the HPLC. Chromatography was performed on a C-8, 15-cm column with a linear gradient from a 95:5 solution of 10 mM pH 4 acetate buffer and THF, to a 90:10 solution of acetonitrile and THF over a period of 28 min. Detection was by UV at 330 nm, and DFMO and norvaline eluted at 14.7 and 17.7 min, respectively. The method was linear over a range of 5 to 950 micrograms/mL, and replicate analyses of a 25-micrograms/mL control specimen produced a between-run coefficient of variation of 6%. No interferences were encountered in a variety of patient and normal serum blanks.
authors.affiliation: University of Southern California, School of Pharmacy, Los Angeles 90033.
authors.forename: J L
authors.initials: JL
authors.lastname: Cohen
authors.forename: R J
authors.initials: RJ
authors.lastname: Ko
authors.forename: A T
authors.initials: AT
authors.lastname: Lo
authors.forename: M D
authors.initials: MD
authors.lastname: Shields
authors.forename: T M
authors.initials: TM
authors.lastname: Gilman
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000097:blood; D002851:Chromatography, High Pressure Liquid; D000518:Eflornithine / Q000097:blood*; D006801:Humans
chemical_list: D000518:Eflornithine