Working Procedure of the Pharmacopoeial Discussion Group — Revised Version 6
The procedure by which the European, Indian, Japanese and US pharmacopoeias harmonise general chapters and excipient monographs: a Pre-PDG concept stage, then Stage 1 (first draft), Stage 2 (official inquiry, published in each pharmacopoeia's forum), Stage 3 (consensus and sign-off), Stage 4 (regional adoption and implementation) and, for chapters evaluated under ICH Q4B, Stage 5 (inter-regional acceptance). Revised version 6, dated October 2025, was signed by all four pharmacopoeias between 31 October and 5 November 2025.
Always verify against the current published text before relying on it for a submission or inspection.
Scope & applicability
Applies to the PDG pharmacopoeias and to the harmonised texts they sign off. For a manufacturer it determines what "harmonised" means on a given chapter or excipient monograph: the sign-off cover sheet lists which provisions each pharmacopoeia adopts and which non-harmonised parts remain local.
Key requirements
- Harmonisation means a substance tested by the harmonised procedure yields the same results and the same accept/reject decision; it is achieved only when the text is official in every PDG pharmacopoeia
- The sign-off cover sheet records, per provision, which pharmacopoeias adopt it ("+") or will not stipulate it ("–"), and lists non-harmonised parts separately
- Residual differences are flagged in each pharmacopoeia's published text with black diamonds
- No PDG pharmacopoeia revises a harmonised text unilaterally; revisions return through the procedure, with an expedited route back to Stage 3A where justified
- Each pharmacopoeia sets its own implementation date after publication, so a signed-off text becomes official on different dates in each region
Implementation tips
- Before claiming one test satisfies USP, Ph. Eur. and JP, read the sign-off cover sheet for that chapter — a "–" or a non-harmonised part is exactly where the claim fails
- Track implementation dates per region, not the sign-off date: the same harmonised text can be official in one pharmacopoeia and still pending in another
Revision notes
Revised version 6 (October 2025) folds non-harmonised attributes/provisions and local requirements into a single "non-harmonised parts" category. Version 5 (January 2025, corrected February 2025) added electronic sign-off and sharing of texts with other world pharmacopoeias; version 4 (October 2023) adapted the procedure to more than three members when the Indian Pharmacopoeia Commission joined.
PDG Working Procedure (Rev. 6): frequently asked questions
Quick answers to common questions about PDG Working Procedure (Rev. 6).
What is PDG Working Procedure (Rev. 6)?
PDG Working Procedure (Rev. 6) — Working Procedure of the Pharmacopoeial Discussion Group — Revised Version 6 — is a guideline issued by the Pharmacopoeial Discussion Group (International (Ph. Eur., IP, JP, USP)). The procedure by which the European, Indian, Japanese and US pharmacopoeias harmonise general chapters and excipient monographs: a Pre-PDG concept stage, then Stage 1 (first draft), Stage 2 (official inquiry, published in each pharmacopoeia's forum), Stage 3 (consensus and sign-off), Stage 4 (regional adoption and implementation) and, for chapters evaluated under ICH Q4B, Stage 5 (inter-regional acceptance). Revised version 6, dated October 2025, was signed by all four pharmacopoeias between 31 October and 5 November 2025.
Who does PDG Working Procedure (Rev. 6) apply to?
Applies to the PDG pharmacopoeias and to the harmonised texts they sign off. For a manufacturer it determines what "harmonised" means on a given chapter or excipient monograph: the sign-off cover sheet lists which provisions each pharmacopoeia adopts and which non-harmonised parts remain local.
What are the key requirements of PDG Working Procedure (Rev. 6)?
PDG Working Procedure (Rev. 6) requires, among other things: Harmonisation means a substance tested by the harmonised procedure yields the same results and the same accept/reject decision; it is achieved only when the text is official in every PDG pharmacopoeia; The sign-off cover sheet records, per provision, which pharmacopoeias adopt it ("+") or will not stipulate it ("–"), and lists non-harmonised parts separately; Residual differences are flagged in each pharmacopoeia's published text with black diamonds; No PDG pharmacopoeia revises a harmonised text unilaterally; revisions return through the procedure, with an expedited route back to Stage 3A where justified.
When was PDG Working Procedure (Rev. 6) last updated?
The current version of PDG Working Procedure (Rev. 6) dates from November 2025. Revised version 6 (October 2025) folds non-harmonised attributes/provisions and local requirements into a single "non-harmonised parts" category. Version 5 (January 2025, corrected February 2025) added electronic sign-off and sharing of texts with other world pharmacopoeias; version 4 (October 2023) adapted the procedure to more than three members when the Indian Pharmacopoeia Commission joined.