This is a ready-to-use stability study protocol for a drug substance or drug product, covering the long-term, intermediate, and accelerated conditions in one document. Replace every <<FILL: ...>> placeholder with your own specifics, set your document numbers and dates, and route it through your normal protocol review and approval before the first batch is placed. A worked filled specimen follows the blank template. Confirm each cited regulation and clause against the current source before you rely on it. This content is general educational reference, not regulatory or professional advice; adapt it to your product and your quality system.
Approval page
| Field | Entry |
|---|---|
| Protocol title | Stability Study, <<FILL: product / drug substance name, strength>> |
| Protocol number | <<FILL: PROT-ID, e.g. STAB-2026-014>> |
| Version | <<FILL: version, e.g. 1.0>> |
| Effective date | <<FILL: date>> |
| Supersedes | <<FILL: prior version or "New">> |
| Study type | New registration / Post-approval change / Ongoing (annual) commitment |
| Product / material, strength, presentation | <<FILL>> |
| Role | Name | Signature | Date |
|---|---|---|---|
| Author (stability coordinator / formulation SME) | <<FILL>> | ||
| Reviewer (QC / analytical) | <<FILL>> | ||
| Approver (Quality Assurance) | <<FILL>> |
1. Objective
To generate stability data for <<FILL: product>> under long-term, intermediate (if triggered), and accelerated storage conditions per ICH Q1A(R2), to support a proposed <<FILL: shelf life / retest period>> of <<FILL: X months>> when stored <<FILL: storage statement, e.g. "at or below 25 C">>, and to detect any significant change that would require a shorter claim or a different storage statement.
2. Scope
This protocol covers <<FILL: drug substance and/or drug product>>, batch(es) <<FILL: batch numbers or "to be assigned at placement">>, packaged in <<FILL: container closure system, exactly as proposed for marketing/use>>. It does not cover in-use stability after first opening or reconstitution, freeze-thaw cycling, or photostability, each of which is addressed under <<FILL: cross-reference to the relevant protocol or this protocol's section 11 if combined>>.
3. Definitions
- Long-term condition: the storage condition intended to reflect the harshest realistic distribution and use condition for the intended market(s), per the climatic zone(s) targeted.
- Intermediate condition: 30 C / 65 percent RH (or the condition your climatic zone filing requires), tested when accelerated data shows significant change, or from day one for high-risk products.
- Accelerated condition: an elevated stress condition used to reveal degradation faster and support extrapolation, subject to Q1E limits.
- Significant change: as defined in ICH Q1A(R2): typically a 5 percent assay shift from the initial value, a specified degradant exceeding its acceptance criterion, failure to meet appearance/physical/functional criteria, or, where applicable, failure of pH or dissolution. Confirm the current wording before issue.
- Primary batch: a batch representative of the manufacturing process and scale proposed for marketing, used to establish the registered shelf life.
4. Responsibilities
| Role | Responsibility |
|---|---|
| Stability coordinator | Maintains the master schedule, pulls samples on time, tracks chamber assignment and inventory, initiates deviations for window misses or excursions. |
| Formulation / analytical development | Authors the protocol, selects attributes, defines the statistical evaluation plan. |
| QC laboratory | Executes validated stability-indicating methods, records results contemporaneously, raises OOS/OOT per the applicable procedure. |
| Quality Assurance | Approves the protocol and the final report, oversees deviations, confirms the conclusion is supported by the data. |
| Regulatory affairs | Confirms the protocol matches the intended filing’s climatic zone(s) and reporting basis. |
5. Batches and representativeness
| Field | Entry |
|---|---|
| Number of primary batches | <<FILL: not fewer than 3, per ICH Q1A>> |
| Batch numbers | <<FILL>> |
| Manufacturing scale | <<FILL: pilot scale or larger; state the fraction of full production scale>> |
| Manufacturing site(s) | <<FILL>> |
| Basis for representativeness | <<FILL: same equipment train, process, and controls as intended commercial production; state any bridging rationale>> |
| Container closure system (as marketed) | <<FILL>> |
| Orientation (liquids in semi-permeable or closure-sensitive containers) | <<FILL: upright / inverted / both>> |
6. Storage conditions
| Condition | Target / tolerance | Trigger to initiate |
|---|---|---|
| Long-term | <<FILL: e.g. 25 C +/- 2 C / 60% RH +/- 5% RH, or 5 C +/- 3 C for refrigerated, or -20 C +/- 5 C for frozen>> | Day one, all batches |
| Intermediate | <<FILL: e.g. 30 C +/- 2 C / 65% RH +/- 5% RH>> | <<FILL: from day one (high-risk product), or only if accelerated shows significant change>> |
| Accelerated | <<FILL: e.g. 40 C +/- 2 C / 75% RH +/- 5% RH, or 25 C / 60% RH for refrigerated product; not applicable for most frozen products>> | Day one, all batches |
State the climatic zone(s) this design supports: <<FILL: e.g. Zone II baseline, plus Zone IVA/IVB if filing there>>.
7. Attributes, specifications, and methods
One row per attribute tested. Do not load every conceivable test at every time point; select attributes susceptible to change on storage and relevant to quality, safety, or efficacy.
| Attribute | Specification / acceptance limit | Method ID (validated, stability-indicating where applicable) | Tested at every time point? |
|---|---|---|---|
| Appearance | <<FILL>> | <<FILL>> | Yes |
| Assay | <<FILL>> | <<FILL>> | Yes |
| Degradation products (specified/unspecified/total) | <<FILL>> | <<FILL>> | Yes |
<<FILL: e.g. dissolution>> | <<FILL>> | <<FILL>> | <<FILL>> |
<<FILL: e.g. water content>> | <<FILL>> | <<FILL>> | <<FILL>> |
<<FILL: e.g. microbial limits / preservative content>> | <<FILL>> | <<FILL>> | <<FILL>> |
<<FILL: e.g. container closure integrity>> | <<FILL>> | <<FILL>> | <<FILL>> |
8. Time-point schedule and pull windows
| Condition | Time points (months) | Pull window |
|---|---|---|
| Long-term | <<FILL: e.g. 0, 3, 6, 9, 12, 18, 24, then annually to claim>> | See table below |
| Intermediate (if triggered) | <<FILL: e.g. 0, 6, 12>> | See table below |
| Accelerated | <<FILL: e.g. 0, 3, 6>> | See table below |
| Time point | Pull window |
|---|---|
| Up to 1 month | <<FILL: e.g. +/- 2 days>> |
| 3 to 6 months | <<FILL: e.g. +/- 5 days>> |
| 9 to 12 months | <<FILL: e.g. +/- 7 to 10 days>> |
| 18 months and beyond | <<FILL: e.g. +/- 14 to 21 days>> |
Testing outside the defined window is a protocol deviation, assessed per section 12. The recorded test date is the actual date of analysis, never the scheduled pull date.
9. Bracketing / matrixing declaration
| Field | Entry |
|---|---|
| Reduced design used? | Yes / No |
| Design type | Bracketing / Matrixing / Both / Full design |
| Factor(s) reduced and levels tested | <<FILL: e.g. strength bracketed to 50 mg and 150 mg extremes, 100 mg covered by bracket>> |
| Justification | <<FILL: reference the development/comparability data supporting the reduction>> |
| Factor(s) explicitly excluded from reduction, and why | <<FILL: e.g. the strength or time point flagged highest risk by development data>> |
See the bracketing and matrixing design rationale for the full justification worksheet if a reduced design is used.
10. Sample quantity
| Field | Entry |
|---|---|
| Units/quantity needed per pull, per attribute | <<FILL>> |
| Retain quantity for confirmatory retest | <<FILL>> |
| Total quantity reserved per batch, per condition | <<FILL>> |
11. Special studies included under this protocol (if combined)
| Study | Included? | Reference |
|---|---|---|
| Photostability (ICH Q1B) | <<FILL: Yes/No>> | <<FILL: this protocol section, or separate protocol ID>> |
| In-use stability | <<FILL>> | <<FILL>> |
| Freeze-thaw / thermal cycling | <<FILL>> | <<FILL>> |
12. Deviation and excursion handling
- A test date outside the defined window, a chamber excursion, or any departure from this protocol is documented as a deviation under
<<FILL: SOP-ID for deviation management>>at the time it is discovered, not retrospectively. - Each deviation carries an impact assessment on the validity of the affected result(s) and, where relevant, on the overall shelf life conclusion.
- Affected samples are not excluded from the data set without a documented, evidence-based justification approved by QA.
13. Statistical evaluation plan
State the plan before any result is generated:
- Regression model form for attributes expected to change over time:
<<FILL: linear / other justified transform>>. - Batch poolability test (slopes and intercepts), significance level:
<<FILL: e.g. 0.25>>. - Shelf life determined by the 95 percent one-sided confidence limit intersecting the specification limit, per ICH Q1E, not by the mean.
- Extrapolation limits: capped at approximately double the long-term coverage and not more than one year beyond it, contingent on no significant change at accelerated; see ICH Q1E shelf-life statistical evaluation worksheet.
14. Acceptance criteria
- All primary batches pass specification across all conditions through the claimed period, or the statistically supported extrapolation.
- No significant change occurs at the accelerated condition within the extrapolation window; if it does, the intermediate condition governs.
- The confidence-limit method, not the mean, sets the proposed shelf life.
- Any bracketed or matrixed design meets its stated justification and remains balanced per ICH Q1D.
- All test dates fall within the defined pull windows, or deviations are documented and assessed.
15. Deliverables
- Completed time-point data for every attribute, condition, and batch defined above.
- A stability study report per section 13’s statistical plan (see the stability shelf-life justification report).
- Any deviations raised, with impact assessments and closure.
16. Revision history
| Version | Date | Author | Summary of change |
|---|---|---|---|
<<FILL: 1.0>> | <<FILL: date>> | <<FILL: author>> | Initial issue. |
17. References
ICH Q1A(R2), Stability Testing of New Drug Substances and Products. ICH Q1E, Evaluation of Stability Data. ICH Q1D, Bracketing and Matrixing Designs for Stability Testing of Drug Substances and Drug Products. ICH Q1B, Photostability Testing of New Drug Substances and Products (if section 11 applies). ICH Q5C, Quality of Biotechnological Products: Stability Testing of Biotechnological/Biological Products (for biologics). 21 CFR 211.166, Stability testing. WHO guidance on climatic zones III and IV storage conditions (for zone IVA/IVB filings).
Confirm the current version and clause numbers of each reference before issue.
Filled specimen
The following shows key sections completed for an illustrative immediate-release tablet, 100 mg, filed for Zone I/II markets. Company, product, and numbers are illustrative; replace them with your own.
Section 5. 3 primary batches (FT-100-201, FT-100-202, FT-100-203), manufactured at pilot scale, one tenth of intended commercial batch size, on the same granulation and compression train and process parameters proposed for commercial production. Packaged in the marketed 60 count HDPE bottle with induction-sealed cap and silica gel desiccant, upright orientation.
Section 6. Long-term 25 C +/- 2 C / 60% RH +/- 5% RH from day one. Intermediate 30 C +/- 2 C / 65% RH +/- 5% RH, triggered only if accelerated shows significant change. Accelerated 40 C +/- 2 C / 75% RH +/- 5% RH from day one.
Section 8. Long-term: 0, 3, 6, 9, 12, 18, 24 months, then annually to 36 months. Accelerated: 0, 3, 6 months. Intermediate (if triggered): 0, 6, 12 months.
Section 9. No reduced design; full design across all 3 batches, all time points, given only one strength and one pack size are in scope for this filing.
Section 13. Linear regression on assay and total degradants versus time; poolability tested at 0.25 significance; shelf life set by the 95 percent one-sided confidence limit against the 90.0 percent lower assay limit; extrapolation, if used, capped at double the long-term coverage and not more than 12 months beyond it, with a written commitment to continue testing to 36 months.
Common inspection findings this protocol prevents
- A protocol silent on the statistical evaluation method, discovered only when the report is written and the mean is used instead of the confidence limit.
- No documented pull-window tolerance, so late or early testing has no defined threshold for when it becomes a deviation.
- Attributes added to the report that were never listed in an approved protocol, with no justification for the addition.
- A bracketing or matrixing design used with no rationale on file, discovered only when an inspector asks why the middle strength was never tested.
- Batches used for the study that are not genuinely representative of commercial scale, discovered when the bridge is challenged at review.
How to adapt this protocol
- Set your document number, product, and batch numbers on the approval page.
- Confirm your storage conditions against the climatic zone(s) you are actually filing in, and against WHO guidance if filing zone IVA/IVB.
- Trim section 7’s attribute list to what is genuinely susceptible to change and relevant to quality, safety, or efficacy for your specific product; do not copy a generic list wholesale.
- If using a reduced design, complete section 9 and attach the full rationale worksheet.
- Confirm every regulation in section 17 against the current published version before issue.