engleski

Single run determination of elemental impurities according to USP/ICH/EP lists of elements by ICP-MS in Nepafenac

The objective of this study is to develop method for the analysis at the recommended maximum acceptable concentration limits for residues of elemental impurities in active pharmaceutical substances based on the combination of three lists of elements (USP <232>, EP (Ch 5.20) and ICH (Q3D)), with an emphasis on the lowest maximum acceptable concentration limits, and it was carried out by inductively coupled plasma - mass spectrometry (ICP-MS) in a single run. Elements which are covered by this method are typically used as process catalysts or reagents during the synthesis of pharmaceuticals. Analysis of elemental impurities is performed at every stage of production process of active pharmaceutical ingredients, including the analysis of intermediates and starting materials. Sample preparation procedure is the most critical point in analysis of elemental impurities, because it is not considered to be only destruction of solids, but also conversion of substance suitable and stable for introduction into ICP instrumentation. One of the most challenging tasks is determination of osmium in the complex matrices due to fact that osmium, when it is exposed to acidic and oxidising environment, produces volatile species. In order to prevent the formation of these species and to prevent false high results due to vapour enrichment in spray chamber, there is a need for stabilisation of osmium during the analysis, and it was carried out by addition of very low concentrations of thiourea. This method achieves a satisfactory recovery of 70-150 % for all the analysed elements in a single ICP-MS run

ICP-MS ; Nepafenac ; Elemental impurities

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