Comparison of Analytical Methods for the Determination of Elemental Impurities in Pharmaceutical Products

Determining elemental impurities in pharmaceutical products is crucial due to the risk of toxicity and adverse reactions, which compromise the safety, efficacy, and stability of drugs. The aims of this review were to assess the evolution of elemental impurity analysis over time, explore and compare the different instrumental analytical techniques. An exploratory search was performed in current and previous editions of official pharmacopoeias, international guidelines and scientific journal databases. Among instrumental techniques, atomic absorption spectrometry (AAS) is low-cost and highly sensitive, although limited to single-element analysis. Inductively coupled plasma optical emission spectroscopy (ICP OES) combines robustness and multielemental capacity, making it suitable for quality control routines. Inductively coupled plasma mass spectrometry (ICP-MS) stands out for its high sensitivity (ng/L levels) and regulatory compliance, despite its high cost. X-ray fluorescence (XRF) is emerging as a rapid and nondestructive screening tool, but with limitations for quantification. It can be concluded that the choice of technique depends on the matrix and the analytical objective, but ICP-MS appears to be the most promising method for ensuring reliability and safety in the analysis of elemental impurities, considering its importance in different fields, such as Pharmacy, Chemistry, Food Science and Medicine.