Registration Dossier

Administrative data

Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2014
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: well performed OECD study with GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2014

Materials and methods

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

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
purity: 99.7 %

In vivo test system

Test animals

Species:
mouse
Strain:
CBA
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Animal Breeding Facility, Jai Research Foundation
- Age at study initiation: 8 - 9 weeks
- Weight at study initiation: 19.3 - 26.1 g
- Housing: individually in solid floor polypropylene mice cages (290 mm x 220 mm x 140 mm)
- Diet: Teklad Certified Global High Fiber Rat / Mice feed from Harlan USA (ad libitum):
- Water: UV sterilized water filtered through Kent Reverse Osmosis filtration system (ad libitum):
- Acclimation period: 9 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 23
- Humidity (%): 64 - 66
- Photoperiod: 12 hrs dark / 12 hrs light

Study design: in vivo (LLNA)

Vehicle:
propylene glycol
Concentration:
0, 25, 50 and 75%
No. of animals per dose:
5
Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)

Results and discussion

Positive control results:
5 mice treated with 25% HCA in propyleneglycol (v/v)
Group Mean DPM 2961.80 +- 841.14
SI = 5.71

In vivo (LLNA)

Resultsopen allclose all
Parameter:
SI
Remarks on result:
other: see above
Parameter:
other: disintegrations per minute (DPM)
Remarks on result:
other: see Remark
Remarks:
Group Nmb. Concentration (%) Nmb of Mice Group Mean DPM Stimulation Index G1 0 (vehicle control) 5 518+-240 1 G2 25 5 581+-236 1.12 G3 50 5 987+-458 1.90 G4 75 5 1030+-367 1.99 G5 25% HCA(positive control) 5 2962+-841 5.71

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
The substance did not demonstrate dermal sensitisaton potential in the local lymph node assay.
Executive summary:

The substance was tested for skin sensitisation according to OECD guideline 429 (LLNA).

A preliminary study was conducted to identify the appropriate test concentrations for the main study (10,25,50 and 75% in propylene glycol).Based on the results from the preliminary assay, foive groups of mice (each comprising 5 females)were selected for the experiment. Three groups were treated with the substance at concentrations of 25, 50 and 75% (w/v) in propylene glycol for three consecutive days (days 0,1 and 2) on the dorsum of both ears (25 µL per ear). One group served as vehicle control and was treated with propylene glycol and another group served as positive control and was treated with HCA (alpha-hexylcinnamaldehyde) at a concentration oof 25%.

Group mean body weights of the treated animals were comparable with the control group and there were no indications of clinical or systemical toxicity in the treated animals.

On day 5, the uptake of 3H-methyl thymidine into the auricular (local) lymph nodes draining at the site of chemical application was measured (5 hours post administration) to assess the lymph node proliferative response.

A positive response for HCA (SI=5.71) confirmed the reliability of the test procedure. Stimulation indices for 25, 50 and 75% in propylene glycol treated groups were 1.12, 1.90 and 1.99 respectively. The SI obtained for the substance at all tested concentrations showed less than three fold increase over the control value.