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Toxicity assessment
of impurities

Supporting your non-genotoxic impurity (NGI) qualification

If your impurity is not mutagenic or carcinogenic, the impurity levels may still need to be justified, to demonstrate that the level of impurity present is safe. Below a threshold, non-genotoxic impurities (NGIs) are accepted but where they are present at a level above the threshold, an impurity qualification is required. NGI qualification requires a weight of evidence assessment, which we can help you with.

Our solution

We can support you in your toxicity risk assessment of non-genotoxic impurities (NGIs) through our in silico software solutions; Vitic and Derek Nexus. Both Vitic and Derek Nexus go beyond carcinogenicity and genotoxicity, allowing you to assess the broader toxicity of your impurities.


Vitic is a source of high-quality, peer-reviewed public and proprietary toxicity data, covering a broad range of endpoints. Vitic can help you to understand if there is existing data available for your compound.

Vitic highlights

Search for data across a broad range of endpoints
Vitic is a database that contains toxicity data for endpoints beyond carcinogenicity and genotoxicity – such as acute toxicity, skin sensitisation, irritation and developmental and reproductive toxicity – which can help to assess the broader toxicity of your impurities. 

Access high-quality public and proprietary data
The toxicity data held within Vitic comes from a wide variety of sources, Vitic contains expert curated, high-quality and peer-reviewed data, from both published and unpublished sources.

Find similar structural analogues using substructure or similarity searches
Where there is no exact match within Vitic, you can make use of the substructure or similarity search functionality.



Derek Nexus is an expert, knowledge-based prediction software that can help you to establish if there is a toxicity hazard associated with your compound.

Derek Nexus highlights

Access expert Structure-Activity Relationship (SAR) knowledge for over 70 endpoints
Derek Nexus contains Structure-Activity Relationship (SAR) knowledge for a broad range of endpoints – including acute toxicity, skin sensitisation, irritation and developmental and reproductive toxicity, and more. The SAR knowledge is derived from both public and proprietary member data sources and is updated as new data becomes available.

Identify any toxicophores highlighting possible hazard
The expert comments associated with a Derek Nexus alert can help you to decide if this compound structure is a concern or not.

Understand the SAR behind predictions 
The scientific comments which accompany a Derek Nexus alert will describe the chemical and biological mechanisms of action where possible.

Regulatory support

Vitic and Derek Nexus can help you with the qualification of impurities from your API or drug product, to determine whether any additional studies are necessary, in relation to the below relevant guidance.


The ICH Q3A (Impurities in New Drug Substances) guideline provides guidance on the qualification of new drug substances produced by chemical synthesis.


The ICH Q3B (Impurities in New Drug Products) guideline provides guidance on the qualification of impurities in new drug products

EMA qualification of non-genotoxic impurities

The EMA qualification of non-GTI guideline provides more guidance on how NGIs can be qualified.

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