3.1 Good Laboratory Practice (GLP) Regulations (FDA 21 CFR Part 58, OECD GLP) & Study Director Responsibilities

Why DABT tests GLP execution

Domain I of the Diplomate of the American Board of Toxicology (DABT) exam spends substantial weight on conducting studies, not only designing them. OpenExamPrep independent study material for this section covers Good Laboratory Practice (GLP) as the quality system that lets a reviewer reconstruct what was planned, what was done, and what was reported. The three texts you will see named on items are the U.S. Food and Drug Administration (FDA) rule 21 CFR Part 58, the U.S. Environmental Protection Agency (EPA) rules 40 CFR Part 160 (studies under the Federal Insecticide, Fungicide, and Rodenticide Act, FIFRA) and 40 CFR Part 792 (studies under the Toxic Substances Control Act, TSCA), and the Organisation for Economic Co-operation and Development (OECD) Principles of GLP.

Those frameworks share a named Study Director, an independent quality function, controlled written instructions, contemporaneous raw data, and an archive. They do not share one statute, one vocabulary, or one product-law trigger. A DABT item that asks who is accountable when in-life dosing, bioanalysis, and histopathology sit at three contract sites is testing whether you can keep single-point study control while still using an OECD Principal Investigator (PI) for a delegated phase.

What GLP is — and what it is not

OECD describes GLP as a managerial quality system covering the organizational process and the conditions under which nonclinical health and environmental safety studies are planned, performed, monitored, recorded, reported, and archived. FDA 21 CFR 58.1 prescribes GLP for nonclinical laboratory studies that support, or are intended to support, applications for research or marketing permits for FDA-regulated articles: human and animal drugs, biological products, medical devices for human use, food and color additives, animal food additives, and electronic products.

GLP does not prove scientific validity of the design. A study can be fully GLP-compliant and still use the wrong species, omit a needed endpoint, or choose doses that never approach a tolerated high dose. Inspectors and quality auditors ask whether the approved protocol was followed, whether original observations can be reconstructed, and whether the signed report matches the data. Whether the design was an appropriate test of the hypothesis is a separate toxicology judgment, taught in Domain I.A (design) and I.C (interpretation).

FDA 21 CFR 58.3 also carves out basic exploratory studies done only to see whether a test article has potential utility, or only to determine physical or chemical characteristics. Studies that use human subjects are clinical (Good Clinical Practice), not GLP. Commercial manufacture of clinical supplies is Good Manufacturing Practice. Early investigative pharmacology, screening cytotoxicity, and many discovery range-finders can therefore be run non-GLP even when they use animals — unless a sponsor later tries to submit them as the pivotal safety evidence. Field trials in animals are outside the FDA Part 58 definition of a nonclinical laboratory study; pesticide field phases are commonly in scope under EPA FIFRA GLP.

When GLP is required versus investigative work

Use GLP when the study is intended as regulatory safety evidence a receiving authority will rely on:

• FDA: pivotal nonclinical safety (repeat-dose toxicity, genotoxicity packages submitted as safety evidence, reproductive and developmental toxicity, carcinogenicity, and safety pharmacology when the study is offered as GLP safety data) supporting an Investigational New Drug (IND) application, New Drug Application (NDA), Biologics License Application (BLA), or device research/marketing permit.
• EPA FIFRA (40 CFR 160): health and environmental studies submitted to support pesticide registration.
• EPA TSCA (40 CFR 792): health, environmental, and chemical-fate studies submitted under TSCA.
• OECD Mutual Acceptance of Data (MAD): a study conducted to the OECD Principles in a facility under a MAD-compliant monitoring program can be accepted by participating governments without duplicative testing.

Investigative non-GLP work remains legitimate: mechanism probes, vehicle scouting, and dose-range finding that will not stand alone as the safety database. Label that work honestly in the protocol and report. A recurring failure mode is running an investigative study loosely, then attempting to “GLP-wash” the report after an unexpected finding appears.

FDA, EPA, and OECD side by side

Do not treat the table as permission to ignore OECD language on a U.S. IND. Many modern packages are multi-site. Sponsors write OECD-style PI assignments into the protocol so each test site has a named scientific lead, while one Study Director still signs the assembled report.

Study Director duties (21 CFR 58.33)

For each nonclinical laboratory study, a scientist or other professional with appropriate education, training, and experience (or a combination) is identified as the Study Director. That person has overall responsibility for technical conduct, interpretation, analysis, documentation, and reporting, and represents the single point of study control. The Study Director must assure that:

1. The protocol, including any change, is approved as provided by 21 CFR 58.120 and is followed.
2. Experimental data, including unanticipated responses of the test system, are accurately recorded and verified.
3. Unforeseen circumstances that may affect quality and integrity are noted when they occur, and corrective action is taken and documented.
4. Test systems are as specified in the protocol.
5. Applicable GLP regulations are followed.
6. Raw data, documentation, protocols, specimens, and the final report are transferred to the archives during or at the close of the study.

If a gavage technician loads the mid-dose syringe into a high-dose cage at 09:10, the Study Director is the person who must know, document, and decide whether the study remains interpretable. Accountability does not dissolve into a team of equally responsible scientists.

Principal Investigator in multi-site studies

OECD GLP created the Principal Investigator because packages split geographically: 13-week in-life at a contract research organization, bioanalysis at a second laboratory, peer-reviewed histopathology at a third. The PI acts on behalf of the Study Director for defined delegated phases at a test site. The Study Director still approves the study plan and its amendments, approves the final report, and remains responsible for whether the study as a whole followed GLP. You cannot assign overall control to a PI.

Test facility management designates a PI when needed, documents replacement of a Study Director or PI, maintains a master schedule and a historical SOP file, names an archive individual, and keeps communication lines open among the Study Director, PI(s), quality assurance, and study personnel. The lead quality-assurance program verifies the study plan and inspects the assembled final report, including PI contributions and test-site quality-assurance statements.

Quality Assurance Unit independence

21 CFR 58.35 requires a Quality Assurance Unit (QAU) that monitors each study to assure management that facilities, equipment, personnel, methods, practices, records, and controls conform to Part 58. The critical sentence: for any given study, the QAU shall be entirely separate from and independent of the personnel engaged in the direction and conduct of that study.

A Study Director cannot quality-assure the study they direct. QAU staff inspecting Study X cannot sit in the Study Director’s reporting chain for Study X. In a small facility the same person might conduct Study A and inspect Study B, but never both roles on one protocol. 21 CFR 58.3(l) defines the QAU as any person or organizational element, except the study director, designated by testing facility management.

Independence is not a gag order. QAU immediately brings problems likely to affect integrity to the Study Director and management, and periodically submits written status reports to both. QAU also maintains the master schedule indexed by test article, keeps copies of protocols, inspects each study at intervals adequate to assure integrity, determines that protocol and SOP deviations were authorized and documented, reviews the final report to confirm it reflects the raw data, and signs a quality-assurance statement listing inspection dates and when findings were reported.

Management, amendments, deviations, raw data, and archives

21 CFR 58.31 requires testing facility management, for each study, to designate the Study Director before initiation, replace that person promptly if needed, assure a QAU exists, assure test and control articles have been appropriately tested for identity, strength, purity, and stability, and assure that personnel, resources, facilities, equipment, materials, and methodologies are available. Management authorizes significant changes to SOPs (21 CFR 58.81). Management does not co-sign away Study Director control of the protocol.

Amendments are planned protocol changes: documented, signed and dated by the Study Director, with reasons, and kept with the protocol before or as the change takes effect (for example, adding a recovery cohort after a documented design review). A deviation is an unplanned departure from the already-approved protocol or from SOPs — a missed blood collection, a temperature excursion, a diet mix-up. Deviations live in the raw data, are authorized by the Study Director, and are assessed for impact. QAU’s job is to confirm authorization and documentation, not to discover the event only while auditing the draft report.

Raw data (21 CFR 58.3) means laboratory worksheets, records, memoranda, notes, or exact copies that result from original observations and activities and are necessary to reconstruct and evaluate the report. Photographs, computer printouts, magnetic media, and verified transcripts of instrument files can be raw data. Corrections use a single-line strikethrough, initials, date, and reason — never an opaque overwrite.

21 CFR 58.190 requires orderly storage and retrieval of raw data, documentation, protocols, final reports, and specified specimens. An archivist (OECD language; FDA requires a designated individual) indexes the material and controls access. 21 CFR 58.195 sets retention from the disposition of the permit application the study supported, or, if results were never submitted, at least two years after the study is completed, terminated, or discontinued. Studies of more than four weeks also require reserve samples from each test and control article batch (21 CFR 58.105(d)).

Separate four inspection ideas on exam day: QAU critical-phase (study-based) inspections of live events such as first dose or necropsy; QAU facility or process inspections of shared systems (archive, computerized systems, animal care); QAU protocol and report audits; and regulatory inspections of the testing facility (21 CFR 58.15, EPA inspectors, or OECD monitoring authorities). Under 21 CFR 58.35(d), FDA can require the dates of QAU inspections, the study and phase inspected, and the inspector’s name. Narrative QAU findings remain internal management tools; they do not replace the Study Director’s signed report.