Authors: Raquel Nogueira Gisele E B Silva Suzane M Queiroz Monique G Mello Werickson F C Rocha
Publish Date: 2012/07/24
Volume: 17, Issue: 5, Pages: 497-510
Abstract
This paper compares the results of the studies carried out with three new candidate certified reference materials CRM of captopril metronidazole and sodium diclofenac which are the first CRMs of these active pharmaceutical ingredients APIs reported in the literature The studies were carried out according to the ISO Guides 34 2009 and 35 2006 and included the determination of organic inorganic and volatile impurities mass fractions evaluation of homogeneity and stability under transport and storage conditions calculation of API mass fractions by mass balance crosschecking of obtained results and estimation of measurement uncertainties The certified property values and corresponding expanded uncertainties obtained from the combined standard uncertainties multiplied by the coverage factor k = 2 for a confidence level of 95 were 99565 ± 093 mg/g for captopril 99887 ± 015 mg/g for metronidazole and 99976 ± 010 mg/g for sodium diclofenac These new CRMs are intended to be used in assay and tests methods including equipment calibration method validation as well as assignment of traceable property values and corresponding uncertainties to noncertified reference materials with the objective to ensure metrological traceability of measurement results to the International System of Units as well as results accuracy and comparabilityThe authors thank Dr Erika M de Carvalho from the NMR laboratory of Fiocruz in Farmanguinhos for the 1HqNMR analysis and Dr Juliano S Barin from the Federal University of Santa Maria for the analysis of inorganics The authors are also grateful to “Cristália Produtos Químicos e Farmacêuticos Ltda” and “Medley S A Indústria Farmacêutica” for their support on the CRM production
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