Article

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.

Bioanalytical Department, Integrated Product Development, Dr. Reddy's Laboratories Ltd, Bachupalli, Hyderabad 500 072, India.
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences (Impact Factor: 2.78). 09/2011; 879(26):2827-33. DOI: 10.1016/j.jchromb.2011.08.006
Source: PubMed

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.

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