Have you considered how GLP toxicology studies influence the regulatory viability of a new compound? In drug development, these studies are a core component of the non-clinical safety package that determines whether a molecule can progress towards human exposure.
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GLP toxicology studies in rodents are conducted under the internationally recognised Principles of Good Laboratory Practice (GLP), a harmonised framework established to ensure the quality, integrity and reproducibility of non-clinical safety studies in health and environmental contexts. These principles define rigorous organisational and procedural standards governing study planning, execution, monitoring, recording, reporting and long-term archiving of data.
By structuring each phase of the study under controlled and auditable conditions, GLP minimises variability and reduces the risk of error. The result is the generation of scientifically robust data that are suitable for regulatory evaluation by authorities such as the EMA and FDA, and for inclusion in formal regulatory submissions.
Why GLP toxicology studies are essential in non-clinical drug development
GLP toxicology studies form the foundation of non-clinical safety evaluation. Before a new compound can be administered to humans, sponsors must demonstrate, through structured and internationally accepted methodologies, that its risk profile has been rigorously characterised.
Regulatory authorities require reliable evidence of safety before clinical trials or commercialisation. GLP toxicology studies meet these expectations by ensuring that safety data are generated under controlled and internationally recognised conditions, in strict adherence to the OECD Principles on Good Laboratory Practice. This includes the use of standard operating procedures (SOPs), qualified personnel, calibrated equipment and independent quality oversight.
These studies help to define and manage potential risks by:
- Establishing dose-response relationships;
- Identifying target organs and potential toxic effects;
- Defining safety margins prior to human exposure;
- Supporting rational dose selection for clinical trials.
One of the key advantages of GLP compliance is the OECD Mutual Acceptance of Data (MAD) System. Under this internationally harmonised framework, data generated in accordance with the OECD Principles in one adhering country are accepted by regulatory authorities in other member countries. This reduces duplication of studies and avoids repetition of animal testing.
What are the types of GLP toxicology studies in rodents
These studies follow specific OECD Test Guidelines and form an essential component of the non-clinical safety assessment required before clinical development. The principal categories include:
- Acute toxicity studies (OECD Test No. 423): designed to assess adverse or lethal effects following a single oral dose, supporting hazard identification and initial risk classification;
- Subacute and subchronic studies (OECD Test No. 407 and 408): repeated-dose toxicity studies conducted over 28 days and 90 days, respectively, to evaluate systemic effects, identify target organs and characterise dose-response relationships;
- Chronic toxicity studies (OECD Test No. 452): long-term exposure studies designed to assess cumulative toxicity and sustained organ-specific effects;
- Reproductive toxicity studies (OECD Test No. 421 and 416): evaluations of fertility, embryonic development and postnatal outcomes, supporting the identification of potential impacts on reproductive function and developmental processes.
In addition to these guideline-based studies, toxicokinetic assessments are frequently integrated within GLP toxicology studies to evaluate systemic exposure, absorption, distribution, metabolism and excretion of the compound within a toxicological context.
GLP toxicology studies across different therapeutic modalities
Compounds intended for human use must undergo structured non-clinical safety evaluation in accordance with internationally recognised standards:
- For small-molecule drugs, GLP toxicology studies provide the foundational assessment of systemic toxicity, target organ effects and dose-response relationships required before clinical progression;
- For biologics, including monoclonal antibodies, recombinant proteins, recombinant vaccines and growth factors, safety evaluation supports the identification of potential systemic and organ-specific effects associated with complex biological mechanisms;
- In the case of Advanced Therapy Medicinal Products (ATMPs), such as gene therapies, cell therapies and tissue-engineered products, non-clinical safety assessment remains a critical step in development;
- Similarly, siRNAs and other therapeutic oligonucleotides require careful assessment of systemic exposure and potential toxicological effects prior to regulatory submission. GLP-compliant studies ensure that the resulting safety data meet the expectations of regulatory authorities.
The only GLP-certified in vivo toxicology infrastructure in Portugal
In drug development, certified infrastructure is a strategic asset that underpins the generation of regulatory-grade safety data.
In Portugal, VectorB2B stands out as the only facility certified to conduct in vivo GLP toxicology studies for rodents, ensuring preclinical studies meet global expectations for quality and compliance.
By combining certified infrastructure with integrated scientific expertise, this model enables the design and execution of safety programmes tailored to each stage of development. Additionally, we provide full regulatory advisory services to support the progression of new compounds towards market entry. Through personalised regulatory roadmaps, our team guides sponsors from preclinical planning to regulatory submission, ensuring alignment with compliance requirements and supporting a more efficient path to regulatory approval.
Explore VectorB2B’s GLP toxicology services to understand how certified in vivo studies can strengthen your non-clinical strategy and support regulatory progression, or contact the team to discuss your programme requirements.
Frequently asked questions (FAQ)
1. Are GLP toxicology studies always required before first-in-human trials?
Non-clinical safety studies submitted to regulatory authorities are generally expected to comply with GLP. The precise scope depends on the development strategy, but GLP toxicology studies are typically required before clinical trials.
2. How long do GLP toxicology studies in rodents typically take?
Timelines vary according to study type. Acute studies may take a few weeks, while repeated-dose or chronic studies can extend over several months, for example.
3. What are the risks of conducting toxicology studies outside a certified GLP facility?
Data generated outside a certified GLP environment may lack regulatory acceptability. This can result in increased development costs and delays in progressing to clinical stages.
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