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Administrative data

skin irritation / corrosion
other: in silico predictions
Type of information:
Adequacy of study:
supporting study
2 (reliable with restrictions)
Justification for type of information:
QSAR prediction: migrated from IUCLID 5.6

Data source

Reference Type:
study report
Report date:

Materials and methods

Principles of method if other than guideline:
Estimated by using ACD/Percepta QSAR model and Toxtree decision rule system.
GLP compliance:

Test material

Constituent 1
Chemical structure
Reference substance name:
Reaction mass of (2R)-2-phenyl-2-[(2R)-piperidin-2-yl]acetamide and (2S)-2-phenyl-2-[(2S)-piperidin-2-yl]acetamide
EC Number:
Molecular formula:
Reaction mass of (2R)-2-phenyl-2-[(2R)-piperidin-2-yl]acetamide and (2S)-2-phenyl-2-[(2S)-piperidin-2-yl]acetamide

Results and discussion

Any other information on results incl. tables

The prediction results of skin irritation are illustrated in the following Table .

 ACD/Percepta prediction  Toxtree prediction  Consensus prediction

ACD/Percepta model for skin irritation estimates the potential of a chemical to cause skin irritation in a standard rabbit Draize test. It calculates the probability for a chemical to cause moderate or above irritation to skin of rabbit at a standard dose of 100 and 500 mg, respectively. It lists all the rules that are applicable and are used in the calculation, it highlights the structural fragments corresponding to the listed rules on the molecule of interest and it provides a list of up to five most similar structures from the training set with the experimental values of their standard Draize test result and references.

 ACD/Percepta Probability to cause moderate or stronger rabbit skin irritation  ACD/Percepta prediction  Reliability assessment

ACD/Percepta predictedc-racemateas skin irritant, with a probability to cause skin irritation equal to 0.74. However, this prediction is considered of little reliability since the target compound is not represented in the model training set (no training compounds with similarity greater than 0.5 with respect to the target were found).

Toxtree predicts the skin irritation caused by a chemical according to the EU risk phrases (R34: Causes burns; R35: Causes severe burns; R38: Irritating to skin). Toxtree predicts the skin irritation caused by a chemical based on physicochemical property exclusion rules and structural inclusion rules. Physicochemical exclusion rules depend on: molecular weight, LogP, melting point, water solubility, lipid solubility and surface tension. Toxtree prediction for the target compound is illustrated in the Table .

 Toxtree exclusion rules  Toxtree inclusion rules  Toxtree prediction
Group CN Vapour pressure (Pa) < 0.0001  No  NOT SKIN CORROSIVE

Toxtree predictedc-racemateas not skin irritant, since it fulfils one exclusion rule since the target belongs to the structural class made of chemicals containing Carbon (C), Hydrogen (H), Oxygen (O) and Nitrogen (N)atomswith a vapour pressure < 0.0001 Pa (EPISuite/MPBPVP estimated vapour pressure = 0.0000593 Pa). In addition, no structural inclusion rule were met.

Therefore Toxtree predicted the targetc-racemateas not skin corrosive. A detailed assessment of the reliability of the prediction is not provided.

Applicant's summary and conclusion

Interpretation of results:
Migrated information with little reliability
The skin irritation potential of the target chemical was predicted employing two different in silico approaches: the QSAR statistical model as provided by ACD/Percepta and the decision rule system provided by Toxtree. The two predictors were employed in order to apply a consensus approach to enhance the reliability of the prediction. The two predictors were not in agreement since ACD/Percepta provided a positive prediction while Toxtree a negative prediction. Although ACD/Percepta prediction resulted to be of little reliability, since Toxtree didn’t provide a detailed assessment of its reliability, and according to a precautionary approach it was concluded with a little level of confidence that the target c-racemate is SKIN IRRITANT.