title: Development and validation of highly sensitive method for determination of misoprostol free acid in human plasma by liquid chromatography-electrospray ionization tandem mass spectrometry: application to a clinical pharmacokinetic study.
abstract: A highly sensitive, selective and evaporation free SPE extraction, ESI-LC-MS/MS method has been developed for estimation of misoprostol free acid in human plasma using misoprostol acid-d(5) as an internal standard (IS). The analyte was separated using isocratic mobile phase on reverse phase column and analyzed by MS/MS in the multiple reaction monitoring mode using the respective [M-H] anions, m/z 367-249 for misoprostol acid and m/z 372-249 for the IS. The total run time was 5.0 min and the elution of misoprostol acid and misoprostol acid-d(5) (IS) occurred at 3.6 min. The developed method was validated in human plasma with a lower limit of quantification of 2.5 pg/mL. A linear response function was established for the range of concentrations 2.5-1200 pg/mL (r>0.998) for misoprostol acid in human plasma. The intra and inter-day precision values for misoprostol acid met the acceptance as per FDA guidelines. Misoprostol acid was stable in the battery of stability studies viz., bench-top, auto-sampler and freeze/thaw cycles. The developed assay method was applied to an oral pharmacokinetic study in humans.
authors.affiliation: Bioanalytical Department, Integrated Product Development, Dr. Reddy's Laboratories Ltd, Bachupalli, Hyderabad 500 072, India. vijayabd@drreddys.com
authors.forename: D
authors.initials: D
authors.lastname: Vijaya Bharathi
authors.forename: B
authors.initials: B
authors.lastname: Jagadeesh
authors.forename: Kishore Kumar
authors.initials: KK
authors.lastname: Hotha
authors.forename: Uday
authors.initials: U
authors.lastname: Patil
authors.forename: Indu
authors.initials: I
authors.lastname: Bhushan
mesh_terms: D000293:Adolescent; D000328:Adult; D002853:Chromatography, Liquid / Q000379:methods*; D004355:Drug Stability; D006801:Humans; D008297:Male; D008875:Middle Aged; D016595:Misoprostol / Q000031:analogs & derivatives* / Q000097:blood / Q000737:chemistry / Q000493:pharmacokinetics; D012044:Regression Analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*; D055815:Young Adult
chemical_list: D016595:Misoprostol; C047042:misoprostol acid