Learn what a GLP study plan should contain, who reviews it, how amendments are handled, and what auditors look for.
Key takeaways
- A GLP study plan—called a protocol in FDA 21 CFR Part 58—sets out the study’s objectives and methods.
- The Study Director is responsible for the study’s technical conduct and for ensuring the approved plan is followed.
- FDA and OECD GLP provisions describe QAU involvement differently; confirm which framework applies.
- Planned changes should be handled as documented amendments. Unplanned departures should be recorded and assessed as deviations.
What is a GLP study plan?
A GLP study plan is the written instruction set for conducting a nonclinical safety study. It defines what the study is intended to establish, how it will be performed, what data will be collected, and how results will be evaluated. In pharmaceutical development, it might govern a repeat-dose toxicity study of a new drug candidate, including dose groups, clinical observations, laboratory tests, and tissue examinations.
FDA regulations generally use the term protocol. Under 21 CFR §58.120, each study must have an approved written protocol describing its objectives and methods. OECD GLP Principles refer to a written study plan and state that it should be approved by the Study Director before the study begins.
GLP governs nonclinical laboratory studies. It is distinct from GMP requirements for manufacturing and batch release, although pharmaceutical companies may use both systems in different parts of development.
What should the plan contain?
The exact required details depend on the applicable regulation and study design. FDA §58.120 lists protocol information such as the study purpose, test and control article identification, test system, experimental design, procedures, records, and statistical methods. Supporting article characterization may be addressed elsewhere in the applicable rules or incorporated by reference.
| Plan section | What to document |
|---|---|
| Study identity | Descriptive title, purpose, and objectives |
| Sponsor and facility | Sponsor and testing facility names and addresses |
| Test and control articles | Identifiers such as name, code, or other distinguishing information; reference supporting characterization records |
| Test system | Relevant details such as species, strain, source, sex, age or weight range, and identification method |
| Design and methods | Groups, controls, procedures, materials, dose levels and routes, observation and measurement schedule, and planned analyses |
| Records and statistics | Records to retain and proposed statistical methods |
| Multi-site arrangements | For applicable OECD multi-site studies, identify sites, principal investigators, and delegated study phases |
For multi-site studies, an integrated plan helps maintain consistent study direction. OECD guidance calls for identifying participating sites and principal investigators and defining the phases delegated to them.
Preparation and approval process
A practical preparation process brings scientific, operational, and quality input together before study work starts:
- Draft the plan. The Study Director develops the objectives, design, methods, records, and analysis approach.
- Check feasibility. Relevant laboratory staff confirm that the proposed equipment, procedures, staffing, sample handling, and schedule can support the work. Applicable SOPs should be identified.
- Resolve open points. Clarify methods, responsibilities, test article information, and any multi-site handoffs before initiation.
- Approve and distribute. Under FDA Part 58, the protocol includes the sponsor’s approval date and the Study Director’s dated signature. The approved version should be available to personnel performing the work.
- Maintain independent QA oversight. FDA’s QAU monitors studies and maintains protocol copies; FDA §58.35 does not describe QAU protocol approval as a substitute for Study Director approval. OECD GLP Principles call for QAU verification of GLP compliance. Check the rules that apply to the facility and study.
The Study Director has overall responsibility for the study’s technical conduct, interpretation, documentation, and reporting. The QAU works independently to monitor compliance and report findings. These responsibilities should remain clear in study records.
Amendments and deviations
An amendment changes the planned study. Under FDA §58.120(b), amendments and their reasons must be documented, signed and dated by the Study Director, and kept with the protocol. For example, changing a planned sampling time because of a justified method constraint should be formally assessed and recorded before the revised procedure is used, where practicable.
A deviation is an unplanned departure from the approved plan. Record what happened, when, why, who was involved, and the impact assessment. For an SOP deviation under FDA GLP, the Study Director’s authorization and documentation in the raw data are required. OECD guidance also addresses documenting, explaining, and acknowledging deviations promptly.
For example, if a scheduled observation is delayed because a test system requires urgent veterinary care, document the event and its scientific impact. If the study design itself must change, evaluate whether a formal amendment is needed.
Audit-ready checks
Before initiation, confirm that:
- The approved plan is the current version and is accessible to study staff.
- Required signatures and dates are present for the applicable framework.
- Methods, responsibilities, test systems, and records are sufficiently clear to conduct and reconstruct the study.
- Multi-site roles and communication routes are defined when applicable. https://iampharmacist.com/glp-computerized-systems/
- Amendments and deviations are traceable, justified, and retained with study records.
Frequently asked questions
1. Is a GLP study plan the same as a protocol?
They are commonly used for the same document. FDA Part 58 uses “protocol”; OECD GLP uses “study plan.”
2. Who prepares the GLP study plan?
The Study Director is responsible for the study’s direction and plan. They may obtain technical input from staff and specialists.
3. Who signs the plan?
Under FDA §58.120, the protocol includes a sponsor approval date and the Study Director’s dated signature. Check any additional local requirements.
4. Does the QAU approve the study plan?
FDA Part 58 gives the QAU an independent monitoring role; it does not specify QAU approval as a replacement for the Study Director’s approval. OECD GLP Principles call for QAU compliance verification.
5. Must the plan be approved before study initiation?
OECD GLP expressly says the plan should be approved by the Study Director before initiation. FDA requires an approved written protocol; facilities should ensure it is approved before the work it governs begins.
6. What is a protocol amendment?
A documented, justified change to the planned study. Under FDA Part 58, the Study Director signs and dates it, and it is kept with the protocol.
7. What is a study deviation?
An unplanned departure from the approved plan or procedure that must be documented and assessed for its effect on the study.
8. Does every protocol need a statistical analysis plan?
FDA §58.120 includes proposed statistical methods among protocol contents. The methods should suit the study design and endpoints.
9. What extra details matter in a multi-site study?
Define participating sites, principal investigators, delegated phases, responsibilities, and communication. OECD multi-site guidance addresses these arrangements.
10. How long must the study plan be retained?
Retention follows applicable GLP regulations and facility procedures. Preserve it with associated study records for the required period and ensure it remains retrievable.