Testing of elemental impurities as heavy metals has been in use for many years. Lack of sensitivity and reproducibility are the main limitations of current heavy metals procedure USP <231>. The procedure described for heavy metals will detect Pb, Hg, Bi, As, Sb, Sn, Cd, Ag, Cu and Mo. The new chapters are designed for safer limits and enhanced detection limits. ICH was proposed a draft consensus guideline and under step 2b version in the year 2013 and posted as official from December 2014 under step 4 version. EMEA released a comment by stating that new marketing authorization for new product should comply with ICH/CHMP guideline effective from June 2016; where a control of an elemental impurity is warranted, an elemental specific method is requested by the guideline. Therefore, a non-specific compendial test for heavy metals will not be accepted. USFDA published the final Q3D Elemental impurities guidance on September 2015. Color comparison of test will be replaced by instrumental techniques like Atomic absorption spectroscopy (AAS), Graphite furnace atomic absorption spectroscopy (GFAAS), Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS).
MM, R., KH, R., & MU, R. (2016). Harmonized Guideline on Limit and Testing of Elemental Impurities in Pharmaceutical Substances: A Review. Pharmaceutical Regulatory Affairs: Open Access, 05(02). https://doi.org/10.4172/2167-7689.1000168