title: Determination of travoprost and travoprost free acid in human plasma by electrospray HPLC/MS/MS.
abstract: A quantitative method for the analysis of AL-5848, the (+)-enantiomer of fluprostenol (FP), in human plasma is described. Plasma was spiked with a tetradeuterated analog of travoprost free acid (AL-5848X) as internal standard (IS) and acidified with 0.1 M formic acid. Sample clean up was performed using reversed phase solid-phase extraction. Following elution of the compounds of interest and evaporation to dryness, the residue was reconstituted in methanol:water (1:1) and chromatographed on an octadecylsilica (C18) column with negative ion electrospray ionization tandem mass spectrometry. The [M[bond]H](-) ions at m/z 457 and 461 for the analyte and IS, respectively, were subjected to collisional fragmentation with argon to yield the same intense 3-trifluoromethylphenolate (m/z 161) product ion. The validated concentration range was 0.010-3.00 ng/ml based on a 1.0 ml plasma aliquot. Fully adequate accuracy, precision, specificity, recovery and stability for routine use in clinical pharmacokinetic studies were demonstrated. Analysis of a second plasma aliquot following incubation with rabbit esterase allows the isopropyl ester pro-drug, travoprost (AL-6221), to be determined by difference.
authors.affiliation: Pharmacokinetics/Drug Metabolism Unit, Alcon Research, Ltd., 6201 South Freeway, Fort Worth, TX 76134-2099, USA.
authors.forename: B A
authors.initials: BA
authors.lastname: McCue
authors.forename: M M
authors.initials: MM
authors.lastname: Cason
authors.forename: M A
authors.initials: MA
authors.lastname: Curtis
authors.forename: R D
authors.initials: RD
authors.lastname: Faulkner
authors.forename: D C
authors.initials: DC
authors.lastname: Dahlin
mesh_terms: D000287:Administration, Topical; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics; D002138:Calibration; D002851:Chromatography, High Pressure Liquid; D003008:Cloprostenol / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000097:blood* / Q000493:pharmacokinetics; D003903:Deuterium; D006801:Humans; D007202:Indicators and Reagents; D011786:Quality Control; D012015:Reference Standards; D015203:Reproducibility of Results; D012997:Solvents; D021241:Spectrometry, Mass, Electrospray Ionization; D000069557:Travoprost
chemical_list: D000959:Antihypertensive Agents; D007202:Indicators and Reagents; D012997:Solvents; D003008:Cloprostenol; D003903:Deuterium; D000069557:Travoprost