Stability Study Protocol: Format & Free Template (ICH Q1A)

2026-06-26

A ready-to-use stability study protocol format aligned to ICH Q1A(R2) — storage conditions, time points, tests and acceptance criteria — with a section-by-section guide, a worked example, and a free Excel template.

Stability Study Protocol — format and free template aligned to ICH Q1A

A stability study protocol is the controlled document that defines how a product's stability will be studied — the storage conditions, time points, tests, and acceptance criteria — before the first sample goes on charge. Get the protocol format right and the whole study (and the shelf life you claim from it) is defensible. Here's a ready-to-use stability protocol format aligned to ICH Q1A(R2), the section-by-section guide, a worked example, and a free template.

⬇ Download the Stability Study Protocol template (Excel) — free, no sign-up. Adapt it to your product and SOP.

What a stability study protocol must contain

These are the sections every protocol needs — the template below has all of them:

SECTION                         WHAT GOES IN IT
------------------------------  --------------------------------------------------------
Protocol no. / version / date   Unique controlled-document id + effective date
Product / strength / generic    What's being studied + dosage form
Batch details                   Batch no(s)., batch size, mfg date, packaging studied
Objective                       Why (registration / on-going / post-change stability)
Storage conditions              The ICH conditions to be used (see table below)
Time points (pull schedule)     Months at which samples are tested
Test parameters + methods       What is tested at each pull + the analytical method
Acceptance criteria             The spec limits each test must meet
Sampling plan / quantity        Units pulled per time point + reserve
Responsibilities                Who charges, pulls, tests, reviews, approves
References                      ICH Q1A(R2), Q1E, pharmacopoeia, the product spec
Approval (prepared/checked/appr) Names, signatures, dates

ICH storage conditions & time points

The conditions and pull schedule are the heart of the protocol. The ICH Q1A(R2) general case:

STUDY TYPE        CONDITION              TIME POINTS (MONTHS)
----------------  ---------------------  --------------------------------------------
Long-term         25°C ± 2 / 60% RH ± 5  0, 3, 6, 9, 12, 18, 24, 36
   (or)           30°C ± 2 / 65% RH ± 5  (Zone IVa / IVb markets — India = 30°C/75%)
Intermediate      30°C ± 2 / 65% RH ± 5  0, 6, 9, 12   (only if long-term is 25°C)
Accelerated       40°C ± 2 / 75% RH ± 5  0, 3, 6

A "significant change" at accelerated (40°C/75%) triggers intermediate-condition testing. For India and other Zone IVb markets, long-term is typically 30°C/75% RH. Match the conditions in your protocol to the markets you're registering in.

Worked example — a filled protocol header

STABILITY STUDY PROTOCOL                          Protocol No: STB/2026/014  (v1.0)
Product:  Moxifloxacin Tablets 400 mg            Effective date: 24-06-2026
Batch No: MX-2406-01   Batch size: 100,000 tabs   Mfg date: 06-2026
Packaging studied: Alu-Alu blister
Objective: Registration stability to support a 24-month shelf life
-------------------------------------------------------------------------------
Condition        Time points (months)              Tests at each pull
---------------  --------------------------------  -------------------------------
Long-term 30/75  0, 3, 6, 9, 12, 18, 24            Description, Assay, Dissolution,
Accelerated      0, 3, 6                            Related substances, Water,
40/75                                               Microbial limits (0, 12, 24)
-------------------------------------------------------------------------------
Acceptance: Assay 90.0–110.0% · Dissolution NLT 80% (Q) in 30 min · Total
            impurities NMT 2.0% · Description: complies
Prepared by: A. Rao (QC)   Checked by: S. Iyer (QA)   Approved by: Head-QA

Notice that microbial limits are tested at fewer pulls (0, 12, 24) than the chemical tests — the protocol defines which tests run at which time point, not "everything every time."

How to write it — section by section

Conditions — pick from the ICH table by the markets you're registering in; don't mix zones in one study without justification.
Time points — define the full pull schedule up front; a missed pull is a deviation, so the schedule must be realistic.
Tests per pull — list the parameter and the method/STP number; some tests (micro, related substances) run at a subset of pulls.
Acceptance criteria — usually the release spec, sometimes with a shelf-life spec; state both if they differ.
Sampling quantity — enough for the tests + reserve/retest at each pull.

From a protocol document to a tracked study

A protocol on paper is a plan; the risk is the execution — a pull date that slips, a time point tested late, a result that breaches spec and isn't escalated. Putting the protocol into a stability tracking system turns each time point into a scheduled, owned task:

The pull schedule becomes dated, assigned pulls with reminders before each is due.
Results are captured against the acceptance criteria so an out-of-spec trend is flagged, not buried.
Charge → pull → test → review is audit-trailed for the registration dossier.

That's the difference between a protocol you wrote and a study you can defend.

Frequently asked questions

What is a stability study protocol?

A controlled document, approved before the study starts, that defines the storage conditions, time points (pull schedule), tests, methods and acceptance criteria for studying a product's stability — and therefore its shelf life.

What are the ICH stability conditions?

General case: long-term 25°C/60% RH (or 30°C/65–75% RH for hot/humid Zone IV markets like India), intermediate 30°C/65% RH, and accelerated 40°C/75% RH. Long-term time points run 0, 3, 6, 9, 12, 18, 24, 36 months; accelerated runs 0, 3, 6.

What is the difference between a protocol and an STP?

The protocol defines the study (conditions, time points, what to test, acceptance criteria). The STP (Standard Test Procedure) defines how to run each individual test. The protocol references the STPs.

Can I get a free stability protocol template in Excel?

Yes — download the template above. It includes the protocol sections, the ICH conditions/time-point grid and a filled example; adapt it to your product and SOP.

Flobri turns a stability protocol into a tracked study — scheduled pulls, results against acceptance criteria, and an audit trail for the dossier — so nothing slips between charge and the shelf-life claim. See stability study tracking.