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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in chemico
Type of information:
experimental study
Adequacy of study:
key study
Study period:
6th June 2018 to 19th July 2018
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018
Report Date:
2018

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 442C (In Chemico Skin Sensitisation: Direct Peptide Reactivity Assay (DPRA))
Deviations:
no
Qualifier:
according to
Guideline:
other: Direct Peptide Reactivity Assay (DPRA) for Skin Sensitization Testing, DB-ALM Protocol n°154
Version / remarks:
January 12, 2013
Deviations:
not specified
GLP compliance:
yes (incl. certificate)
Type of study:
direct peptide binding assay
Justification for non-LLNA method:
Reduction in animal testing by use of a validated non-vertebrate test, in accordance with the requirements to consider non-vertebrate testing for this endpoint, in accordance with the REACH regulation.

Test material

Reference
Name:
Unnamed
Type:
Constituent
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: PharmaZell, batch no. 12/18
- Expiration date of the lot/batch: not specified
- Purity test date: not specfied, but CoA states retest data in March 2019

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature
- Stability under test conditions: assumed to be stable
- Solubility and stability of the test substance in the solvent/vehicle: assumed to be stable
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: assumed non-reactive

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: The test item was pre-weighed into a glass vial and was dissolved in an appropriate solvent previously determined in a pre-experiment. A stock solution with a concentration of 100 mM was prepared. A factor of 1.04 was used to correct for the purity of the test item
- Preliminary purification step (if any): none
- Final dilution of a dissolved solid, stock liquid or gel: None; stock solution was used directly with peptide solutions

FORM AS APPLIED IN THE TEST (if different from that of starting material) : a solution of the solid was used in the test, and mixed at specified ratios with the peptide solutions

In chemico test system

Details on study design:
Skin sensitisation (In chemico test system) - Details on study design:

The in chemico direct peptide reactivity assay (DPRA) enables detection of the sensitising potential of a test item by addressing the molecular initiating event of the adverse outcome pathway (AOP), namely protein reactivity, by quantifying the reactivity of test chemicals towards synthetic peptides containing either lysine or cysteine. The percentage depletion value of the cysteine and lysine peptide is used to categorize a substance in one of four reactivity classes to support discrimination between skin sensitisers and non-sensitisers.

Results and discussion

Positive control results:
Mean Cysteine peptide depletion = 71.18% (SD= 0.06%, CV = 0.08%)
Mean Lysine peptide depletion = 58.47% (SD = 2.23%, CV = 3.81%)
Prediction model 1, mean of peptides depletions = 64.83%

In vitro / in chemico

Resultsopen allclose all
Key result
Parameter:
other: % Cysteine Peptide depletion
Run / experiment:
1
Value:
0.41
Vehicle controls validity:
valid
Negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
no indication of skin sensitisation
Key result
Parameter:
other: % Lysine peptide depletion
Run / experiment:
1
Value:
1.07
Vehicle controls validity:
valid
Negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
no indication of skin sensitisation
Key result
Parameter:
other: Mean of both % peptide depletions
Run / experiment:
1
Value:
0.74
Vehicle controls validity:
valid
Negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
no indication of skin sensitisation
Other effects / acceptance of results:
OTHER EFFECTS:
- Visible damage on test system: none stated

DEMONSTRATION OF TECHNICAL PROFICIENCY: not stated.

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: Yes
- Acceptance criteria met for positive control: Yes
- Acceptance criteria met for variability between replicate measurements: Yes

Any other information on results incl. tables

Depletion of the Cysteine Peptide

Cysteine Peptide

Sample

Peak Area at 220 nm

Peptide Conc. [mM]

Peptide Depletion [%]

Mean Peptide Depletion [%]

SD of Peptide Depletion [%]

CV of Peptide Depletion [%]

Positive Control

4.7290

0.1451 

71.19

71.18

 

0.06 

0.08

4.7400 

0.1454 

71.12

4.7210 

0.1449 

71.24

Test Item

16.6830 

0.5110 

0.00

0.41 

 

0.57 

140.65

16.3680 

0.5014 

1.06

16.5170 

0.5060

0.16

Depletion of the Lysine Peptide

Lysine Peptide

Sample

Peak Area at 220 nm

Peptide Conc. [mM]

Peptide Depletion [%]

Mean Peptide Depletion [%]

SD of Peptide Depletion [%]

CV of Peptide Depletion [%]

Positive Control

6.2940 

0.2177 

56.28

58.47

2.23

3.81

5.9870 

0.2071 

58.41

5.6530 

0.1955 

60.73

Test Item

14.5170 

0.5025 

0.22

1.07

0.80

74.95

14.3800

0.4977 

1.16

14.2860 

0.4945 

1.81

 

 

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
In this study under the given conditions the test item showed minimal reactivity towards both peptides. The test item is considered as “non-sensitiser”.