Elemental impurities analysis in name-brand and generic omeprazole drug samples

Elemental impurities in drug samples can generate unwanted pharmacological–toxicological effects, therefore they must be carefully monitored. In order to update the elemental analysis of pharmaceutical products, new regulations for elemental impurities were published by the United States Pharmacopoeia (USP). This work presents elemental analysis of 23 analytes in omeprazole drug samples from seven different commercial brands considering reference, similar and generic medicines using inductively coupled plasma mass spectrometry (ICP-MS). Microwave-assisted digestion using 2.0 mol L(−1) HNO(3) (partial digestion) was applied successfully for omeprazole drugs. Most analytes were below the respective limits of quantification, except for As, Ba, Cd, Co, Cu, Cr, Li, Mo, Ni, Pb, Sb and V. However, the determined concentrations for these analytes were lower than the limits proposed by the USP Chapter 232 and similar for all products, inferring that for the seven analyzed samples there is no difference among reference, similar and generic drugs considering contaminants contents. Discussions considering potential risks of elemental contamination taking into account diverse brands were presented.