Journal of Trace Elements and Minerals (Dec 2022)
From the Limit Test for Trace Elements Control to the Elemental Impurities Analysis by Inductively Coupled Plasma Optical Emission Spectrometry: Application on Six Samples of Metronidazole API
Abstract
Introduction: The objective of this work was to control the inorganic impurities by the trace elements and sulfuric ashs limit tests and to analyze the elemental impurties by Inductively Coupled Plasma Optical Emission Spectrometry (ICP OES) wich is a novel method based on security data in six samples of Metronidazole API, collected from six pharmaceutical industries installed in Algeria. Materials and Methods: For the trace elements and sulfuric ashs limit tests, a muffle furnace and a sand bath were used for samples calcination and each sample was processed according to the limit tests of European Pharmacopoeia eighth edition (Eur Ph 8 th ed). For the elemental impurities analysis, an ICP OES device was used for analysis of trace elements in diverse samples and each sample was processed according to the new procedures of American Pharmacopoeia USP 40-NF 35. Results: The results of trace elements and sulfuric ashs limit tests showed that all samples were conform except M1 sample wich contained more than 20 ppm of trace elements. The ICP OES elemental impurities analysis showed that the content of class 1 elements (Cd, Pb, As and Hg) and class 3 elements (Cu, Sn and Cr) of all samples was in the required limits. The content of class 2 elements (Co, Ni and Ag) was in the required limits in all samples except M3 sample which had Nickel content (3.5 ppm) exceeded the authorized limit for the parenteral route (2 ppm). Knowing that Nickel interferes very weakly with Osmium, this may be explained by the fact that this sample was intended to be put into oral forms. Conclusion: The highlighting of Nickel impurity exceeding safety standards confirm that trace elements test is neither specific nor exact, so it's recommended to manufacturers and quality control laboratories to apply the new procedures based on safety data which are well described in the new chapters (232) and (233) of USP or the general chapter 2.4.20 of Eur Ph.