4,4'-methylenebis(2,6-diisopropylaniline)

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

July 2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

Lonzacure M-DIPA

IUPAC Name:

Lonzacure M-DIPA

Test material form:

solid: compact

Details on test material:

- Identity: Lonzacure M-DIPA
- Molecular Weight: 366.6 g/mol
- Appearance: Solid, white to brown
- Solubility: In EtOH, acetone, acetonitrile, and DMSO > 1 g/L
- Stability in Solvent: In H2O, EtOH, acetone, acetonitrile, and DMSO > 96 hours
- Storage: At room temperature protected from light
- Expiration Date: December 31, 2009

In vivo test system

Test animals

Species:

mouse

Strain:

other: CBA/CaOlaHsd

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Harlan Netherlands, B.V. Postbus 6174, NL - 5960 AD Horst / The Netherlands
- Age at study initiation: 7-8 weeks
- Housing: signle caging
- Diet (e.g. ad libitum): pelleted standard diet, ad libitum, Harlan Winkelmann GmbH, 0-33178 Borchen
- Water (e.g. ad libitum): tap water, ad libitum, Gemeindewerke, 0-64380 Rossdorf
- Acclimation period: yes

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3°C
- Humidity (%): 30-84%
- Photoperiod (hrs dark / hrs light): artificial light 6.00 a.m. - 6.00 p.m.

Study design: in vivo (LLNA)

Vehicle:

acetone/olive oil (4:1 v/v)

Concentration:

concentrations of 10, 25 and 50% (w/v) were tested

No. of animals per dose:

- Number of animals for the pre-test: 2 females
- Number of animals for the main study: 16 females
- Number of animals per group: 4 females (nulliparous and non-pregnant)
- Number of test groups: 3
- Number of control (vehicle) groups: 1

Details on study design:

Each test group of mice was treated by topical (epidermal) application to the dorsal surface of each ear lobe (left and right) with different test item concentrations of 10, 25, and 50% (w/v) in acetone:olive oil (4+1). The application volume, 25 ul was spread over
the entire dorsal surface (mean ca. 8 mm) of each ear lobe once daily for three consecutive days. A further group of mice was treated with an equivalent volume of the relevant vehicle alone (control animals).

Positive control substance(s):

hexyl cinnamic aldehyde (CAS No 101-86-0)

Statistics:

The mean values and standard deviations were calculated in the body weight tables.

Results and discussion

Positive control results:

Summary:
- Experiment performed in May 2007; considered to be valid
- Positive control substance: a-Hexylcinnamaldehyde
- Vehicle: acetone:olive oil (4+1)
- Substance concentrations: 5, 10 and 25% (w/v)

Results:
- S.I.: 2.43-4.88
- EC3 value: 6.7%

In vivo (LLNA)

Results

Results 1

Key result

Parameter:

SI

Value:

3.8

Test group / Remarks:

test item conc. 10%

Results 2

Key result

Parameter:

SI

Value:

3.64

Test group / Remarks:

test item conc. 25%

Results 3

Key result

Parameter:

SI

Value:

1.97

Test group / Remarks:

test item conc. 50%

Results 4

Key result

Parameter:

EC3

Remarks on result:

not determinable because of methodological limitations

Remarks:

EC3 could not be calculated since the SI at the lowest test concentration was above 3

Any other information on results incl. tables

All treated animals survived the scheduled study period and no signs of toxicity were observed.

Applicant's summary and conclusion

Interpretation of results:

sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The test item was found to be a skin sensitiser under the described conditions of this LLNA assay.

Executive summary:

In the study according to OECD no. 429 and EU B.42, the test item dissolved in acetone:olive oil (4+1) was assessed for its possible contact allergenic potential. For this purpose a local lymph node assay was performed using test item concentrations of 10, 25, and 50%. In this study Stimulation Indices (S.I.) of 3.80, 3.64, and 1.97 were determined with the test item at concentrations of 10, 25, and 50% in acetone:olive oil (4+1), respectively. The test item was found to be a skin sensitiser under the described conditions.