title: Uncertainty in liquid chromatographic analysis of pharmaceutical product: influence of various uncertainty sources.
abstract: An ISO GUM measurement uncertainty estimation procedure was developed for a liquid-chromatographic drug quality control method-assay of simvastatin in drug formulation. In quantification of uncertainty components several practical approaches for including difficult-to-estimate uncertainty sources (such as uncertainty due to peak integration, uncertainty due to nonlinearity of the calibration curve, etc.) have been presented. Detailed analysis of contributions of the various uncertainty sources was carried out. The results were calculated based on different definitions of the measurand and it was demonstrated that unequivocal definition of the measurand is essential in order to get rigorous uncertainty estimate. Two different calibration methods - single-point (1P) and five-point (5P) - were used and the obtained uncertainties and uncertainty budgets were compared. Results calculated using 1P and 5P calibrations agree very well. The uncertainty estimate for 1P is only slightly larger than with 5P calibration.
authors.affiliation: Institute of Chemical Physics, University of Tartu, Jakobi 2, 51014 Tartu, Estonia; State Agency of Medicines, Nooruse 1, 50411 Tartu, Estonia.
authors.forename: Signe
authors.initials: S
authors.lastname: Leito
authors.forename: Kadi
authors.initials: K
authors.lastname: Mölder
authors.forename: Allan
authors.initials: A
authors.lastname: Künnapas
authors.forename: Koit
authors.initials: K
authors.lastname: Herodes
authors.forename: Ivo
authors.initials: I
authors.lastname: Leito
mesh_terms: D002138:Calibration; D002853:Chromatography, Liquid / Q000379:methods*; D008962:Models, Theoretical; D004364:Pharmaceutical Preparations / Q000032:analysis*; D035501:Uncertainty
chemical_list: D004364:Pharmaceutical Preparations