USP defers elemental impurities guidelines
The USP and ICH are working to harmonise guidelines on metal impurities in drugs and ingredients
The Elemental Impurities Expert Panel met in September to review the Step 2 limits of the ICH Q3D Elemental Impurities Working Group, which were released in June 2013. At its meeting the Expert Panel recommended revisions to General Chapter <232> Elemental Impurities—Limits to partially align with the ICH Q3D limits. In addition, the Expert Panel recommended other minor editorial changes to both General Chapter <232> and General Chapter <233> Elemental Impurities—Procedures. On October 16-17, 2013 the General Chapters—Chemical Analysis Expert Committee met and endorsed the recommendations of the Expert Panel.
The latest update from the US Pharmacopeial Convention (USP) expert panel provides a new timeline for implementation. The new timeline envisages pre-publication of the proposed revisions by 1 January 2014, for review by Council of Experts Executive Committee, followed by publication in Pharmacopeial Forum (PF) by 1 March for public comment. That will set in play a series of reviews culminating in publication in USP 38-NF 33 First Supplement in February 2015 and becomes official on 1 August of that year.
Meanwhile, the European Directorate on the Quality of Medicines and Healthcare (EDQM) has also said it will not continue implementation of Chapter 5.20 Metal catalyst or Metal reagent residues until the ICH Q3D guideline for elemental impurities has been finalised. 5.20 is based on European Medicines Agency (EMA) guideline EMEA/CHMP/SWP/4446/2000, which has been applicable to new medicinal products since September 2008 and would have become applicable to existing marketed products as of 1 September 2013. 'As a consequence, chapter 5.20 … will not now become legally binding as of 1 April 2014,' said the EDQM in a statement.
The existing ICH Q3A Guideline classifies impurities as organic, inorganic, and residual solvents. The Q3A and Q3B Guidelines effectively address the requirements for organic impurities. An additional Guideline Q3C was developed to provide clarification of the requirements for residual solvents. The proposed new Guideline Q3D would provide similar clarification of the requirements for metals, which are included in the ICH inorganic impurities classification.
