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.
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ABSTRACT: This monograph is based on a graduate course that has been taught at UC Davis since 1976. The subjects covered have been selected primarily for their pedagogical value and are restricted to transport processes in porous media. Most of the material can be covered in 28 one-hour lectures; however, shorter versions of a course can easily be developed by omitting several sections that are especially time consuming or by omitting one or more of the five chapters. The problems at the end of each chapter represent an integral part of the monograph and the solutions are available from the author.edited by Jacob Bear, 01/1999; Kluwer Academic Publishers., ISBN: 0-7923-5486-9
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ABSTRACT: The modeling of the unit operation of vacuum contact drying is approached as a multi-scale problem. At the particle assembly length scale, effective transport properties (thermal conductivity, relative gas- and liquid-phase permeability) have been determined computationally by simulations on reconstructed porous media and verified by direct measurements. A distributed-parameter model of vacuum contact drying including liquid and vapor flow and differential energy balance has been formulated and used for the calculation of drying time as function of vacuum level, temperature, vessel diameter, and batch size at the unit operation length scale. Drying curves for a model system of sodium carbonate–isopropanol have been measured experimentally and compared with the model predictions. A very good agreement has been found.Drying Technology 07/2007; 25(7-8):1265-1273. · 1.81 Impact Factor
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ABSTRACT: The effective thermal conductivity of mono- and poly-dispersed random assemblies of spherical particles and irregular crystals, both dry and partially or fully saturated by wetting and non-wetting liquids, has been determined computationally by numerical solution of the Fourier’s law on 3-D reconstructed media and experimentally by the transient hot wire method. The effect of spatial distribution and volume fractions of the vapour, liquid, and solid phases on effective thermal conductivity was systematically investigated. A power-law correlation for estimating the effective conductivity, valid over a wide range of phase volume fractions and relative conductivities of components, has been proposed.International Journal of Heat and Mass Transfer. 01/2004;