N,N''-(methylenedi-4,1-phenylene)bis[N'-cyclohexylurea];N-(4-[[4-[[(phenylamino)carbonyl]amino]phenylmethyl]phenyl]-N'-cyclohexylurea;reaction mass of: N,N''-(methylenedi-4,1-phenylene)bis[N'-phenylurea]

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

18 October, 1994 - 18 November, 1994

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted according to OECD Guideline 406 and GLP principles.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1994

Report date:

1994

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

(1992)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Version / remarks:

(1992)

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: "Allergic Contact Dermatitis in the Guinea-Pig: Identification of Contact Allergens" Magnusson B. Kligman A.M., 1970 published by C.C. Thomas, Springfield, Illinois, USA

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

423-070-8

EC Name:

-

Cas Number:

58890-25-8

Molecular formula:

not applicable (reaction mass)

IUPAC Name:

3-cyclohexyl-1-[4-({4-[(cyclohexylcarbamoyl)amino]phenyl}methyl)phenyl]urea; 3-cyclohexyl-1-[4-({4-[(phenylcarbamoyl)amino]phenyl}methyl)phenyl]urea; 3-phenyl-1-[4-({4-[(phenylcarbamoyl)amino]phenyl}methyl)phenyl]urea

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name of test material (as cited in study report): KY-RB
- Description: White powder

In vivo test system

Test animals

Species:

guinea pig

Strain:

Himalayan

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: BRL Ltd., Basel, Switzerland
- Age at study initiation: Approx. 6 weeks
- Weight at study initiation: 323 - 464 g
- Housing: Group housing of 2 animals per labelled metal cage with wire-mesh floors.
- Diet: free access to standard guinead pig diet, including ascorbic acid; LC 23-B, pellet diameter 4 mm.
- Water: free access to tap water diluted with decalcified water.
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21
- Humidity (%): 50
- Air changes (per hr): approx. 15
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal and epicutaneous

Vehicle:

propylene glycol

Induction 2

Concentration / amount:

Intradermal injections: 1%
Epidermal applications: 25%
Challenge: 5, 10 and 25%

Challenge

Challenge 1

Route:

epicutaneous, occlusive

Vehicle:

propylene glycol

Challenge 2

Concentration / amount:

Intradermal injections: 1%
Epidermal applications: 25%
Challenge: 5, 10 and 25%

No. of animals per dose:

Test animals: 10
Control animals: 5

Details on study design:

RANGE FINDING TESTS (4 animals)

For the intradermal induction exposure (1 animal):
- Concentration: 0.2 and 1% (w/w)
- Amounts: 0.1 mL were injected into two injection sites in the right and left clipped scapular regions.
- Scoring: the skin reactions were scored 24 and 48 hours after application
- Result: The intradermal injections resulted in an acceptable level of necrosis. The 1% test substance concentration was the maximum suitable concentration and was selected for the main study.

For the epicutaneous induction (same animal as used for the intradermal induction and 3 other animals):
- Concentration: 25% test sustance concentration was chosen as the highest useable concentration, as higher concentrations were dry and not homogeneous. Test substance concentrations of 1, 5, 10 and 25% were tested to the animals.
- Amount: 0.5 mL, to the shaved flank
- Exposure period: 24 hours (occlusive)
- Scoring: the skin reactions were scored 24 and 48 hours after patch removal
- Result: no signs of irritation at the highest concentration of 25%. Therefore the test sites were treated with 10% SDS approx. 24 hrs before the epidermal induction in the main test.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 2

1) Intradermal injections on day 1:
- Concentration: 1%
- Site: scapular region.
Three pairs of intradermal injections:
1) 0.1 mL: FCA (50% in water)
2) 0.1 mL: 1% test substance in propylene glycol (control animals: 0.1 mL of propylene glycol)
3) 0.1 mL: 50% with 2% test substance + 50% FCA (undiluted).
- Use of SDS (all animals): on day 7, 24 hrs before the topical induction application, the scapular area between the injection sites was clipped and subsequently rubbed with 10% SDS in petrolatum using a spatula.

2)Topical application on day 8:

- Amount: 0.5 mL (control animals: 0.5 mL of propylene glycol), on the SDS treated area
- Area: approximately 8 cm^2
- Exposure period: 48 hours (occlusive)
- Readings: scores were rated directly after patch removal

B. CHALLENGE EXPOSURE (all animals)
- Day of challenge: day 22
- Concentration: 5, 10 and 25% in propylene glycol
- Exposure period: 24 hours (occlusive)
- Site: flank
- Amount: 0.05 mL of the diluted substance; 0.05 mL of propylene glycol
- Readings: scores were rated 24 and 48 hours after patch removal

Challenge controls:

Not applicable

Positive control substance(s):

yes

Remarks:

(the results of the latest reliability check, performed in July 1994 with HCA, are reported)

Results and discussion

Positive control results:

The latest reliability check (performed less than 6 months ago) shows a sensitisation rate of 100%.

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

5, 10 and 25%

No. with + reactions:

2

Total no. in group:

10

Clinical observations:

None

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 5, 10 and 25%. No with. + reactions: 2.0. Total no. in groups: 10.0. Clinical observations: None.

Results 2

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

5, 10 and 25%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

None

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 5, 10 and 25%. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: None.

Results 3

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

0% (propylene glycol)

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

None

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 0% (propylene glycol). No with. + reactions: 0.0. Total no. in groups: 5.0. Clinical observations: None.

Results 4

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

0% (propylene glycol)

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

None

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 0% (propylene glycol). No with. + reactions: 0.0. Total no. in groups: 5.0. Clinical observations: None.

Any other information on results incl. tables

RANGE FINDING TESTS (4 animals)

For the intradermal induction exposure:

- Result: The intradermal injections resulted in an acceptable level of necrosis. The 1% test substance concentration was the maximum suitable concentration and was selected for the main study.

For the epicutaneous induction (same animal as used for the intradermal induction and 3 other animals):

- Result: no signs of irritation at the highest concentration of 25%. Therefore the test sites were treated with 10% SDS approx. 24 hrs before the epidermal induction in the main test.

Main test:

- Five test group animals showed slight erythema after the 48 hours occluded epidermal induction exposure. The control animals showed no skin reactions.

- No mortality occurred and no symptoms of systemic toxicity were observed in the animals.

- The average body weight gain of experimental and control animals was considered to be similar.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

In this adjuvant type guinea pig test method for skin sensitisation according to OECD 406 guideline and GLP principles, two out of ten test substance group animals (sensitisation rate of 20%) showed a positive reaction in response to the 25%, 10% and 5% KY-RB concentrations.

Executive summary:

KY-RB was tested in an adjuvant type guinea pig test method for skin sensitisation according to OECD 406 guideline and GLP principles. No mortality occurred and no symptoms of systemic toxicity were observed in the animals. Five test group animals showed slight erythema after the 48 hours occluded epidermal induction exposure.

Two out of ten test substance group animals showed a positive reaction in response to the 25%, 10% and 5% KY-RB challenge concentrations (sensitisation rate of 20%). Reliable negative and positive controls were included. Based on the results, KY-RB does not need to be classified as a skin sensitiser in accordance with Regulation (EC) No 1272/2008.