Development studies of a new metronidazole certified reference material

This paper presents the results of the studies carried out with the candidate certified reference material (CRM) of metronidazole, first CRM of this active pharmaceutical ingredient (API) available on the market and second Brazilian CRM of an API. The investigation includes the determination of organic impurities, inorganic impurities and volatiles, validation of the HPLC-DAD method, stability studies under transport and storage conditions, homogeneity testing, calculation of metronidazole content by mass balance, confirmation of the certified value by differential scanning calorimetry (DSC), and estimation of measurement uncertainties.