1Where ICH Q1 stands.
The ICH Management Committee endorsed a concept paper and business plan in November 2022, and an Expert Working Group was set up to revise the stability series, Q1A to Q1F and Q5C.¹ The Step 2 draft, Stability Testing of Drug Substances and Drug Products, was endorsed on 11 April 2025 and released for public consultation.² ICH lists its status as Step 3. The consultation deadlines fell in 2025, among them 25 August for FDA, 28 August for Japan’s MHLW/PMDA and 31 August for Health Canada.¹
The date for the final text has moved. The work plan dated 11 February 2026 expected Step 3 sign-off and Step 4 adoption in November 2026.³ The work plan dated 10 July 2026 expects Expert Working Group consensus in November 2026, then Step 3 sign-off and Assembly review for Step 4 in December 2026, after the Prague meeting. Training material is due in June 2027.⁴
Until the final version is adopted and implemented, the current guidelines apply. FDA published the draft in June 2025 as draft guidance marked “Not for implementation”.⁵ The EMA still lists Q1A(R2) as the current effective version, legally effective since 1 August 2003.⁶ ICH’s own Step 2 presentation says the document “will undergo changes through Step 4 and should not be used or referenced as the final Guideline”.⁷
2What the consolidation merges.
The draft calls itself “a consolidated revision that supersedes ICH Q1A-F and Q5C guidelines”.² Its structure differs from the existing series, so content can sit in a section a reader would not expect.⁷
| Current guideline | Step 4 | Where its content goes in the draft |
|---|---|---|
| Q1A(R2) Stability testing of new drug substances and products | 6 February 2003 | Sections 3 to 7, on protocol design, batches, container closure, testing frequency and storage conditions, and section 15 on commitments |
| Q1B Photostability testing | 6 November 1996 | Section 8, Photostability |
| Q1C New dosage forms | 6 November 1996 | Section 15.4, new dosage forms and strengths |
| Q1D Bracketing and matrixing | 7 February 2002 | Annex 1, Reduced stability protocol design |
| Q1E Evaluation of stability data | 6 February 2003 | Section 13, Data evaluation, and Annex 2, Stability modelling |
| Q5C Stability of biotechnological and biological products | 30 November 1995 | Combined with the Q1A content in sections 2 to 7 |
Dates and mapping come from ICH’s guideline page and the Step 2 presentation.¹⁷ Q1F, on climatic zones III and IV, was withdrawn in June 2006, when ICH left those storage conditions to the regions and WHO.¹ The draft now sets out storage conditions for all four climatic zones.²
3What is new in the draft.
The scope is wider. It covers synthetic chemical entities, including oligonucleotides and polypeptides, and biologicals such as therapeutic proteins, antibody-drug conjugates, vaccines, allergenic products and adjuvants. Cell- and gene-based advanced therapies, the drug constituent of a drug-device combination, and co-packaged solvents and diluents are also in scope. It is applicable to all regulatory submissions and, in accordance with regional regulations, can apply to generics and biosimilars; its principles also support post-approval changes. Device constituent parts, radiopharmaceuticals and whole blood products are excluded.² It is “not directly applicable” to products in clinical development, though its concepts can apply in proportion to product and process understanding.²
The Step 2 presentation lists the new content:⁷
- Section 9, processing and holding times for intermediates, including when data go in a submission and when they can be managed in the pharmaceutical quality system.
- Section 10, short-term storage conditions, for products that state them on the label.
- Section 11, in-use stability.
- Section 12, reference materials, novel excipients and vaccine adjuvants.
- Section 15, product lifecycle stability studies, including post-approval changes.
- Annex 1, knowledge- and risk-based protocol reductions alongside bracketing and matrixing.
- Annex 2, enhanced stability modelling.
- Annex 3, advanced therapy medicinal products, “supplemental to the core ICH Q1 Draft Guideline and is not a stand-alone guideline”.
Section 2 gathers development studies under stress and forced conditions and divides them in two. Stress studies use conditions more severe than accelerated without necessarily degrading the sample; forced degradation deliberately degrades it to find degradation pathways and to confirm that analytical procedures are stability-
4What changes for storage conditions and data packages.
The familiar conditions stay, with additions and some changes.⁸²
| Condition | Q1A(R2), drug product | Draft ICH Q1 |
|---|---|---|
| Long-term, room temperature | 25°C/60% RH or 30°C/65% RH | The same, plus 30°C/75% RH and, for zone III, 30°C/35% RH, set out by climatic zone from I to IVb |
| Intermediate | 30°C/65% RH, where long-term is 25°C/60% RH | 30°C/65% RH or 30°C/75% RH, where long-term is 25°C/60% RH |
| Accelerated | 40°C/75% RH | 40°C/75% RH |
| Semi-permeable containers, intermediate | 30°C/65% RH | 30°C/35% RH |
| Refrigerated, accelerated | 25°C/60% RH | 25°C, or a justified alternative; humidity control may not be needed when justified |
| Frozen | −20°C ± 5°C, with storage below −20°C handled case by case | −20°C or below |
Tolerances are ±2°C and ±5% RH for room-temperature conditions and ±3°C for 5°C storage in both texts.⁸² Both say that excursions beyond the defined tolerances for more than 24 hours should be described in the study report and their effect assessed; the draft moves this from the glossary into the storage conditions section.⁸²
The draft sets the minimum data at submission by product type. A new synthetic drug substance or product needs three primary batches with 12 months of long-term and 6 months of accelerated data, which matches Q1A(R2). An existing synthetic product in an abbreviated or abridged submission needs 6 months of each, and a biological product 6 months of long-term data on three batches.²⁸
5How it runs in Seal.
In Seal’s stability management, each study keeps the protocol version it executed, and a protocol amendment preserves the pulls already run under the earlier version. Each pull records its units, times and handoffs from chamber to laboratory, and a missing result stays visible as work with an owner and a source. Where bracketing or matrixing is used, the justification stays with the protocol version that applies it.
Neil, Seal’s AI agent, can plan the next stability pulls from protocol windows, chamber inventory and testing capacity, for the study planner to confirm, and review a stability trend by comparing time points against the recorded limits. The study owner assesses the trend; a trend summary does not establish shelf life or change a specification.
References
- 1Quality Guidelines, ICH. https:/
/ www. ich. org/ page/ quality- guidelines (read 6 November 2026) - 2ICH Q1 Stability Testing of Drug Substances and Drug Products, Step 2 draft, ICH, endorsed 11 April 2025. https:/
/ database. ich. org/ sites/ default/ files/ ICH_ Q1EWG_ Step2_ Draft_ Guideline_ 2025_ 0411. pdf (read 6 November 2026) - 3ICH Q1 EWG Work Plan, ICH, 11 February 2026. https:/
/ database. ich. org/ sites/ default/ files/ ICH52_ Q1_ EWG_ WorkPlan_ 2026_ 0318. pdf (read 6 November 2026) - 4ICH Q1 EWG Work Plan, ICH, 10 July 2026. https:/
/ database. ich. org/ sites/ default/ files/ ICH53_ Q1_ EWG_ WorkPlan_ 2026_ 0818. pdf (read 6 November 2026) - 5Q1 Stability Testing of Drug Substances and Drug Products, Draft Guidance for Industry, FDA, June 2025. https:/
/ www. fda. gov/ regulatory- information/ search- fda- guidance- documents/ q1- stability- testing- drug- substances- and- drug- products (read 6 November 2026) - 6ICH Q1A (R2) Stability testing of new drug substances and drug products, Scientific guideline, European Medicines Agency. https:/
/ www. ema. europa. eu/ en/ ich- q1a- r2- stability- testing- new- drug- substances- drug- products- scientific- guideline (read 6 November 2026) - 7ICH Q1 Step 2 Presentation, ICH, 11 April 2025. https:/
/ database. ich. org/ sites/ default/ files/ ICH_ Q1_ Step2_ Presentation_ 2025_ 0411_ 0. pdf (read 6 November 2026) - 8ICH Q1A(R2) Stability Testing of New Drug Substances and Products, ICH, 6 February 2003. https:/
/ database. ich. org/ sites/ default/ files/ Q1A%28R2%29%20Guideline. pdf (read 6 November 2026)
AQuestions and answers
Can we use the draft ICH Q1 now?
Not as a final guideline. FDA marks its version not for implementation, the EMA still lists Q1A(R2) as current, and ICH says the draft will change before Step 4. Reading it shows where the text is heading, but studies are still designed to the current guidelines.
When will the new ICH Q1 be final?
ICH’s July 2026 work plan expects Step 3 sign-off and Assembly review for Step 4 in December 2026, a month later than the February plan. Each regulator then implements it on its own timetable, as it did for the guidelines it replaces.
Does ICH Q1 replace ICH Q5C?
Once adopted, yes. The draft supersedes Q5C along with Q1A to Q1F, and brings the stability of biotechnological and biological products into the same sections as synthetic products, with product-specific guidance where it differs.
Does the new guideline cover cell and gene therapies?
Yes. Autologous and allogeneic cell-based products and gene therapy products are in scope, with additional considerations in Annex 3. That annex supplements the core guideline and is not a stand-alone guideline for advanced therapies.
Do the standard ICH storage conditions change?
Most stay the same: 25°C/60% RH or 30°C/65% RH long-term, and 40°C/75% RH accelerated. The draft adds 30°C/75% RH as a long-term option, sets out conditions for each climatic zone, and changes some conditions for semi-permeable containers and refrigerated products.