In April 2004, EMEA's Guideline on Control of Impurities of Pharmacopoeial Substances: Compliance with the European Pharmacopoeia General Monograph "Substances for Pharmaceutical Use" and General Chapter "Controls of Impurities in Substances for Pharmaceutical Use" came into force (CPMP/QWP/1529/04).

This guideline was created due to the fact that some API monographs of the European Pharmacopoeia - so-called 'old' monographs - are outdated as to their specifications regarding impurities (mostly 'related substances'), i.e. they are not in compliance with the current regulations, e.g. the General Ph.Eur. Monograph 'Substances for Pharmaceutical Use' or the ICH Guideline on Impurities ICH Q3A(R). At the same time it is absolutely necessary that specific API monographs exist that take the current state of the art and knowledge into account.

For this reason, the new guideline suggests that the process of revising the 'old' monographs should be carried out simultaneously by the EDQM (European Department for the Quality of Medicines) and by the registration authorities.

In this context it is planned that the European Pharmacopoeia continues its ongoing revision programme, possibly setting priorities for individual substances. The 'Certificate of Suitability' (CEP) must not be issued any more if the corresponding monograph has not yet been updated with regard to the limits for impurities.

In parallel to this, the registration authorities have to check for every application dossier whether the API monograph mentioned therein is up to date, and if not, whether the - in this case necessary - additional specifications on impurities have been included. Moreover, the European Pharmacopoeia has to be informed that the API monograph in question needs to be revised.