The need for international harmonisation

Globalisation and the ever-increasing expansion in international trade have highlighted the need to develop and maintain global quality standards for medicines.

Pharmacopoeial standards are a vital cog in the smooth functioning of marketing authorisation and market surveillance processes as well as in the free movement and trade of medicines across the globe. As such, the European Pharmacopoeia (Ph. Eur.) is actively engaged in a number of international harmonisation initiatives, including:

  • bilateral harmonisation efforts with pharmacopoeias from other regions or countries;
  • working in an informal structure called the Pharmacopoeial Discussion Group (PDG);
  • actively participating in the International Meeting of World Pharmacopoeias (IMWP).

The EDQM's European Pharmacopoeia Department, represents the Ph. Eur.  and its groups of experts and working parties within these initiatives.

The Pharmacopoeial Discussion Group (PDG)

The PDG brings together:

  • the Ph. Eur., the Indian Pharmacopoeia Commission (IPC), the Japanese Pharmacopoeia (JP) and the United States Pharmacopoeia (USP);
  • the World Health Organization (WHO) as an observer.


The PDG was formed in 1989 by the European Directorate for the Quality of Medicines of the Council of Europe (the forerunner of the EDQM), the Japanese Pharmacopoeia of the Ministry of Health, Labor, and Welfare and the United States Pharmacopeial Convention, Incorporated. WHO joined as an observer in May 2001 and the Group continued to function in this configuration until the launch of a pilot for expansion at the end of 2021. This pilot represents a landmark first step in the PDG’s commitment to expanding the recognition of harmonised pharmacopoeial standards, with the ultimate goal of harmonising standards worldwide. To ensure that the PDG continues to work efficiently and produce high-quality harmonised standards, it has defined clear entry criteria and a detailed Framework for the pilot phase. Having received significant interest, the PDG reviewed the applications and agreed by consensus to launch a one-year pilot phase with the Indian Pharmacopoeia Commission (IPC), which began in October 2022. At the PDG Annual Meeting in Hyderabad in October 2023, IPC was welcomed as a PDG member. The PDG is currently reflecting on both the process it followed for the expansion and how the Group’s working methods can be streamlined and improved in order to ensure that it continues to perform efficiently also in view of further expansion.


The PDG works to harmonise excipient monographs and general chapters, reducing the burden placed on manufacturers to perform analytical procedures in different ways depending on the jurisdiction. At all times, the PDG works to reflect the latest scientific advancements while championing public health protection.

Please refer to the PDG Statement of Harmonisation policy for more information.


After assessing proposals received (e.g. from associations of manufacturers of pharmaceuticals and excipients), the PDG selects candidate general chapters describing test methods and excipient monographs to add to its work programme. Since 2001, the PDG has organised, on request, ad hoc meetings with industry representatives. As part of its commitment to continuous improvement, the Group has started reflecting on its working methods with a view to encouraging greater stakeholder participation and transparency.

Each topic on the international harmonisation work programme is assigned to one of the participating pharmacopoeias, which takes the lead in co-ordinating the drafting of the text in question. The harmonised text is then published for public comment on the respective forums of the pharmacopoeias.

Once all member pharmacopoeias have agreed on a final, harmonised text, it is signed-off by the PDG and implemented according to the usual procedure employed by each member.

The PDG’s mandate covers the technical harmonisation of the text; each pharmacopoeia is free to adapt the style and format to its own requirements. This includes the freedom to adjust the reference materials and general chapters described.

Please refer to the PDG's working procedures for more information.

Guidance on harmonised texts

Ph. Eur. General chapter 5.8. Pharmacopoeia harmonisation provides essential guidance to users on the PDG’s harmonisation efforts and how information is presented in respective Ph. Eur. texts. This chapter helps users to understand and correctly apply harmonised texts.

You can find details about the status of individual texts and agreements reached on them by the members of the PDG on the following pages:

International Meeting of World Pharmacopoeias (IMWP) and Good Pharmacopoeial Practices (GPhP)

First convened by WHO in 2012, the IMWP brings together pharmacopoeias from across the globe, with the aim of fostering international co-operation and harmonisation by promoting fruitful discussions and information exchanges. The regular meetings of the IMWP are attended by representatives from national, regional and international pharmacopoeias, all of which are committed to working towards harmonisation and strengthening WHO's role in the development of global standards for the production and testing of medicines. The development of GPhP to promote prospective harmonisation is perhaps the IMWP’s greatest achievement to date.

The GPhP were developed by pharmacopoeial representatives under the auspices of the WHO Expert Committee on Specifications for Pharmaceutical Preparations (ECSPP).

The primary aim was to define approaches and policies for establishing pharmacopoeial standards in general, with a particular focus on harmonisation. The set of principles laid down in the GPhP provide guidance on the design, development and maintenance of pharmacopoeial standards for national, regional and international pharmacopoeias. While the GPhP initially focussed on pharmaceutical ingredients and medicinal products, two new chapters – on monographs for compounded preparations and monographs on herbal medicines – have since been added. These chapters were published in the 52nd report of the WHO ECSPP (Annexes 6 and 7, respectively).

International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH)

ICH is a unique organisation that brings together regulatory authorities and the pharmaceutical industry to discuss scientific and technical aspects of drug registration. Since its founding in 1990, it has been ICH's mission to promote and support harmonisation worldwide to ensure that safe, effective and high-quality medicines are developed and registered efficiently. Like other organisations, ICH has had to adapt to an increasingly globalised drug development industry. Its main vehicle for achieving harmonisation is the development of ICH guidelines that are established through a process of scientific consensus and collaboration between regulators and industry experts.

The ICH Assembly brings together all members and observers of the ICH Association as the overarching governing body of the organisation. As an observer, the EDQM contributes to the development of ICH guidelines in a number of relevant areas, including the control of impurities, the development and validation of analytical procedures and continuous manufacturing.

The PDG is working to engage other ICH pharmacopoeias in the Q4B Annexes maintenance process, successfully launching a proof-of-concept study on three ICH Q4B annexes.

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