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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
secondary literature
Justification for type of information:
data is from safety assessment reports

Data source

Reference
Reference Type:
secondary source
Title:
LLNA assay for the test chemical
Author:
OECD QSAR toolbox v3.4
Year:
2018
Bibliographic source:
OECD QSAR toolbox v3.4, 2018

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Principles of method if other than guideline:
To assess the dermal sensitization potential of the test chemical in mice
GLP compliance:
not specified
Type of study:
mouse local lymph node assay (LLNA)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid
Details on test material:
Name of the test chemical:
Ammonium 4-[(2E)-2-[(2E)-2-[2-chloro-3-[(E)-2-[1,1-dimethyl-3-(4-sulfonatobutyl)benzo[e]indol-3-ium-2-yl]vinyl]cyclohex-2-en-1-ylidene]ethylidene]-1,1-dimethyl-benzo[e]indol-3-yl]butane-1-sulfonate
Molecular Formula: C46H50ClN2O6S2.H4N
Molecular Weight: 844.53 g/mol
Substance Type: Organic
Physical State: Solid

In vivo test system

Test animals

Species:
mouse
Strain:
CBA
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS

- Females (if applicable) nulliparous and non-pregnant: [yes/no/not specified]:nulliparous and non-pregnant
- Age at study initiation:young adult animals (approx. 9 weeks olds)
- Weight at study initiation: body weight variation was within +/- 20% of the sex mean.

Study design: in vivo (LLNA)

Vehicle:
propylene glycol
Concentration:
10%, 25% and 50%
No. of animals per dose:
20 females (nulliparous and non-pregnant)
Details on study design:
vehicle control: 0% test substance, 100% propylene glycol
Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)
Statistics:
no data available

Results and discussion

Positive control results:
The SI values calculated for the substance concentrations 5, 10 and 25% were 1.5, 1.9 and 6.1 respectively. An EC3 value of 13.9% was calculated using linear interpolation. The calculated EC3 value was found to be in the acceptable range of 2 and 20%. The results of the 6 monthly HCA reliability checks of the recent years were 9.5, 13.1, 14.1 and 13.8%.

In vivo (LLNA)

Results
Parameter:
SI
Test group / Remarks:
5 per group
Remarks on result:
other: The SI values calculated for the substance concentrations 10, 25 and 50% were 1.1, 2.1 and 2.7 respectively.
Cellular proliferation data / Observations:
Mean DPM/animal values for the experimental groups treated with test substance concentrations 10, 25 and 50% were 311, 590 and 782 respectively. The mean DPM/animal value for the vehicle control group was 287.

Any other information on results incl. tables

Skin reactions/irritation: Green/brown staining by the test substance prevented scoring for erythema. No oedema was observed in any of the animals examined. Macroscopy of the auricular lymph nodes and surrounding area: All nodes of the experimental and control groups were considered normal in size, except for the lymph nodes of one animal at 50%. No macroscopic abnormalities of the surrounding area were noted.

Body weights: Body weights and body weight gain of experimental animals remained in the same range as controls over the study period.

Toxicity and mortality: No mortality occurred and no symptoms of systemic toxicity were observed in the animals of the main study.

Applicant's summary and conclusion

Interpretation of results:
other: not sensitizing
Conclusions:
The SI values calculated for the substance concentrations 10, 25 and 50% were 1.1, 2.1 and 2.7 respectively.Since there was no indication that the test substance elicits an SI>=3 when tested up to 50%, the
test substance was considered not to be a skin sensitizer.
Executive summary:

LLNA assay was conducted to determine the dermal sensitization potential of the test chemical.The study was performed according to OECD 429 Guidelines. 20 females (nulliparous and non-pregnant)CBA mice were used for the study. 10%, 25% and 50% of the test chemical in propylene glycol was applied to the ears of mice.Hexyl cinnamic aldehyde and propylene glycol were used as positive and vehicle controls respectively.

After few days following the initial application, draining lymph nodes were excised. A single cell suspension of LNC was prepared. Incorporation of [3H]TdR was measured, and recorded as mean cpm ± standard deviation (SD) per node of three mice for each group.The incorporation of [3H]TdR was measured using a liquid scintillation counter and expressed as mean counts per min (cpm) + standard deviation per node of three animals for each test group. Increases in [3H]TdR incorporation relative to vehicle-treated controls were calculated for each test group and expressed as stimulation indices (SI). The SI values calculated for the substance concentrations 5, 10 and 25% were 1.5, 1.9 and 6.1 respectively. An EC3 value of 13.9% was calculated using linear interpolation. The calculated EC3 value was found to be in the acceptable range of 2 and 20%. The results of the 6 monthly HCA reliability checks of the recent years were 9.5, 13.1, 14.1 and 13.8%.

The SI values calculated for the substance concentrations 10, 25 and 50% were 1.1, 2.1 and 2.7 respectively.Since there was no indication that the test substance elicits an SI>=3 when tested up to 50%, the

test substance was considered not to be a skin sensitizer.