QSAR

Regulatory background

QSAR models enable the prediction of toxicological and physicochemical properties based on molecular structure – without animal testing.
They are recognised by ECHA (under REACH and BPR) and EFSA (for plant protection products) if they comply with the OECD validation principles:

• clearly defined endpoint

• comprehensible algorithm

• documented quality and application domain

• mechanistic or physicochemical explanation

Recognised tools include the OECD QSAR Toolbox, VEGA, ECOSAR and CASE Ultra.

Benefit from us through:

• Authority-compliant QSAR reports (ECHA/EFSA compatible)

• Rapid, animal-free assessment

Areas of application by endpoints

Physical and chemical properties:

• Log Kₒw, water solubility, vapour pressure
• Melting/boiling point, decomposition rate

Ecotoxicity and environmental behaviour:

• Prediction of acute and chronic effects on aquatic organisms from algae, daphnia and fish toxicity (ECOSAR, VEGA)
• Bioaccumulation (BCF models)
• Persistence/degradation (QSAR Toolbox, VEGA)

Skin and eye irritation/sensitisation:

• Skin sensitisation (OECD QSAR Toolbox)
• Irritation/corrosion (VEGA, QSAR Toolbox)

Genotoxicity and mutagenicity:

• Screening models for mutagenic potential VEGA (Ames, chromosomal aberration), QSAR Toolbox

Endocrine activity (screening):

• VEGA, QSAR Toolbox (ER/AR-Binding)

QSAR models are firmly established in drug development and are recognised by the EMA, FDA and in accordance with ICH guidelines (e.g. M7, S1B).
They support early risk assessment, drug optimisation and impurity evaluation – quickly, cost-effectively and without animal testing.

Recognised tools: Derek Nexus, Sarah Nexus, Leadscope, VEGA, OECD QSAR Toolbox, ADMET Predictor.

Toxicological endpoints:

Early safety profiling to minimise development risks:

• Mutagenicity (Ames test): Derek/Sarah Nexus, Leadscope (ICH M7)
• Cardiotoxicity (hERG): VEGA, ADMET Predictor
• Hepatotoxicity / DILI: VEGA, DILIrank

Impurities & metabolites:

• Mandatory application according to ICH M7: Assessment of potentially genotoxic impurities using two QSAR systems (rule-based + statistical).

Endocrine and systemic effects:

• Screening for hormonal or secondary toxicological effects (VEGA, OECD Toolbox).

Phase II, Tier A:

• Quantitative structure-activity relationships (SAR)

Phase II, Tier B:

• Quantitative structure-activity relationships (SAR)