Registration Dossier

Administrative data

Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2015
Report Date:
2015

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
GLP compliance:
yes (incl. certificate)
Type of study:
mouse local lymphnode assay (LLNA)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: crystalline
Specific details on test material used for the study:
Supplier: Changzou Foreign Trade Corp.Batch No.: 0041A25 (20141211)Physical state: solid substance, crystalline powderColour: whiteStorage: in a cool, dry place, protected from light

In vivo test system

Test animals

Species:
mouse
Strain:
CBA/Ca
Sex:
female
Details on test animals and environmental conditions:
Species and strain: CBA/Ca Ola Hsd miceSource: TOXI-COOP ZRT.Hygienic level duringthe study: Good conventionalNumber of animals: 28 animals/main testSex: Female, nulliparous, non-pregnantAge of animals: Young adult mice;11-12 weeks old (at start of the main test)Body weight range at starting: 18.5-23.4 gThe weight variation in animals involved in the study did not exceed ± 20 % of the mean weight.Acclimatization time: 7 daysAnimal health: Only healthy animals were usedHousing during acclimatization period: Grouped caging in small groupsHousing during the test: Grouped caging (4 animals/cage)Cage type: Type II. Polypropylene / polycarbonateBedding: Laboratory beddingLight: 12 hours daily, from 6.00 a.m. to 6.00 p.m.Temperature: 22 ± 3 °CRelative humidity: 30 – 70 %Housing/Enrichment: Mice were group-housed to allow social interaction, and with deep wood sawdust bedding, to allow digging and other normal rodent activities.

Study design: in vivo (LLNA)

Vehicle:
dimethylformamide
Concentration:
Based on the preliminary test results the test item was examined in the main test at 25 %, 10 %, 5 % and 2.5 % (w/v) concentrations as formulations in N,N-Dimethylformamide (DMF).
No. of animals per dose:
4 animals/treatment group
Details on study design:
Animals in the treatment groups were treated with the relevant vehicles (DMF or AOO), appropriate formulations of the test item or 25 % (w/v) concentration of the positive control substance. The test item was administered at four different concentrations according to the results of the dose range finding test. For detailed data see the table below.Each mouse was topically treated with 25 μL of the appropriate formulations of the test item, the positive control substance or the vehicles (see Table 3) using a pipette, on the dorsal surface of each ear. After the treatments animals were returned to their cages. Each animal was dosed once a day for three consecutive days (Days 1, 2 and 3). There was no treatment on Days 4, 5 and 6.All animals have been monitored daily for systemic toxicity or excessive skin irritation. In case of failed treatment, systemic toxicity or excessive irritation the respective dose-group is excluded from evaluation.
Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)

Results and discussion

Positive control results:
The positive control group animals were treated with 25 % (w/v) HCA solution (dissolved in AOO) concurrent to the test item groups. No mortality, cutaneous reactions or signs of toxicity were observed in the positive control group.Significant lymphoproliferative response (SI ≥ 3) was noted for HCA (SI = 6.9). The results of the positive control item demonstrated appropriate performance of the test in accordance with the relevant guidelines and confirmed validity of the assay.

In vivo (LLNA)

Results
Remarks on result:
other: no skin sensitization potential

Any other information on results incl. tables

Test GroupName

Measured

DPM/group

Group*

DPM

DPN

(DPM/Node)

Stimulation

IndexValues

Vehicle control for the positive control: AOO

8610

8585.0

1073.1

1.0

Positive control:
25 % HCA
in AOO

59201

59176.0

7397.0

6.9

Amidinothiourea (CAS No. 2114-02-5) 25% in DMF

16022

15997.0

1999.0

2.2

 Amidinothiourea (CAS No. 2114-02-5) 10% in DMF

3694

3669.0

458.6

0.5

 Amidinothiourea (CAS No. 2114-02-5) 5% in DMF

6502

6477.0

809.6

0.9

 Amidinothiourea (CAS No. 2114-02-5) 2,5% in DMF

7503

7478.0

934.8

1.0

Vehicle control for the test item: DMF

7184

7159.0

894.9

1.0

*Group DPM = measured DPMgroup- average DPMbackground

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
In conclusion, under the conditions of the present Local Lymph Node Assay, AMIDINOTHIOUREA (CAS No. 2114-02-5) tested at the maximum attainable concentration of 25 % (based on solubility) and at concentrations of 10 %, 5% and 2.5 % (w/v) as formulations in an appropriate vehicle (DMF) was shown to have no skin sensitization potential.