terephtalic acid compound with diamines

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

28 October, 2015 - 23 November, 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

(July 2010)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

(May 2008, including most recent amendments)

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2600 (Skin Sensitisation)

Version / remarks:

(March 2003)

Deviations:

no

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name of test material (as cited in study report): Reaction mixture of 1,4-Butanediamine, 1,6-Hexanediamine and 1,4-Benzenedicarboxylic acid
- Appearance: White crystalline powder

In vivo test system

Test animals

Species:

mouse

Strain:

other: CBA/J

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Janvier, Le Genest-Saint-Isle, France
- Age at study initiation: Young adult animals (approx. 10 weeks old)
- Weight at study initiation: 19.9 - 23.2 g
- Housing: Animals were group housed in labeled Makrolon cages.
- Diet: Free access to pelleted rodent diet (SM R/M-Z from SSNIFF® Spezialdiäten GmbH, Soest, Germany).
- Water: Free access to tap water.
- Acclimation period: At least 5 days

ENVIRONMENTAL CONDITIONS (set conditions)
- Temperature (°C): 18 – 24
- Humidity (%): 40 - 70
- Air changes (per hr): at least 10
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (LLNA)

Vehicle:

other: Water (Elix, Millipore S.A.S., Molsheim, France) with 1% pluronic L92 (BASF, New Jersey, USA).

Concentration:

0, 10, 25 and 50%

No. of animals per dose:

5

Details on study design:

WEIGHT OF EVIDENCE ANALYSIS
In the interest of animal welfare and to minimize any testing likely to produce severe responses in animals, a weight of evidence analysis was performed prior to the start of this study. All available information was evaluated (e.g. existing human and animal data, literature, substance data supplied by the Sponsor, analysis of structure activity relationships (SAR), physicochemical properties and reactivity (pH, buffering capacity)). It was concluded by the Study Director that no severe effects were to be expected.

RANGE FINDING TESTS:
Two test substance concentrations were tested; a 25% and 50% concentration. The highest concentration was the maximum possible concentration as required in the test guidelines.
The test system, procedures and techniques were identical as those used in the main study except that the application method may have been different and that the assessment of lymph node proliferation and necropsy were not performed. Two young adult animals per concentration were selected. Each animal was treated with one concentration on three consecutive days. Animals were group housed in labeled Makrolon cages. Ear thickness measurements were conducted using a digital thickness gauge prior to dosing on Days 1 and 3, and on Day 6.
Animals were sacrificed after the final observation.

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: Local Lymph Node Assay
- Criteria used to consider a positive response: DPM values are presented for each animal and for each dose group. A Stimulation Index (SI) is calculated for each group using the individual SI values. The individual SI is the ratio of the DPM/animal compared to the DPM/vehicle control group mean.
If the results indicate a SI ≥ 3, the test substance may be regarded as a skin sensitizer.

ANIMAL ASSIGNMENT
Three groups of five animals were treated with one test substance concentration per group. One group of five animals was treated with vehicle.

TREATMENT PREPARATION AND ADMINISTRATION:
Test substance preparation: The test substance preparations (w/w) were prepared within 4 hours prior to each dosing. No adjustment was made for specific gravity of the vehicle. Homogeneity was assessed by visual inspection of the solutions.
Rationale for vehicle: The vehicle was selected on the basis of maximizing the solubility using the test substance data provided by the Sponsor and trial preparation results performed at WIL Research Europe.

Induction - Days 1, 2 and 3; Excision of nodes - Day 6; Tissue processing for radioacitivity - Day 6; Radioactivity measurements - Day 7; Performed according to test guidelines.

Observations:
Mortality/Viability: Twice daily.
Body weights: On Day 1 (pre-dose) and Day 6 (prior to necropsy).
Clinical signs: Once daily on Days 1-6 (on Days 1-3 between 3 and 4 hours after dosing).
Irritation: Once daily on Days 1-6 (on Days 1-3 within 1 hour after dosing) according to the following numerical scoring system. In addition, a description of all other (local) effects was recorded according to guidelines.

Necropsy: No necropsy for gross macroscopic examination was performed according to protocol.

Positive control substance(s):

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

Statistics:

Not performed.

Results and discussion

Positive control results:

The six-month reliability check with Alpha-hexylcinnamicaldehyde indicates that the Local Lymph Node Assay as performed at WIL Research Europe B.V. is an appropriate model for testing for contact hypersensitivity. See attached background material.

In vivo (LLNA)

Results

Key result

Parameter:

SI

Value:

>= 0.8 - <= 1.4

Variability:

The SI values calculated for the substance concentrations 10, 25 and 50% were 1.2, 0.8 and 1.4, respectively.

Remarks on result:

other: disintegrations per minute (DPM)

Remarks:

Mean DPM/animal values for the experimental groups treated with test substance concentrations 10, 25 and 50% were 862, 614 and 1036 DPM, respectively. The mean DPM/animal value for the vehicle control group was 731 DPM and for the positive control group (25%) was 4551 DPM.

Any other information on results incl. tables

Results Pre-screen test:

No irritation and no signs of systemic toxicity were observed in any of the pre-screen animals. White staining of test substance remnants on the dorsal surface of the ears of all animals between Days 1 and 4, did not hamper scoring for erythema. Variations in ear thickness during the observation period were less than 25% compared to Day 1 pre-dose values. Based on these results, the highest test substance concentration selected for the main study was a 50% concentration.

Other results - main study:

No irritation was observed in any of the animals. White staining of test substance remnants on the dorsal surface of the ears of all experimental animals between Day 1 and 4, did not hamper scoring for erythema.

 

All auricular lymph nodes of the animals of the experimental and control groups were considered normal in size. No macroscopic abnormalities of the surrounding area were noted for any of the animals.

 

No test substance related mortality occurred and no clinical signs of systemic toxicity were observed in the animals of the main study. Body weights and body weight gain of experimental animals remained in the same range as controls over the study period.

One animal treated at 10%, died before thymidine injection. Based on the available data, it was considered that the study outcome was not adversely affected.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

In an LLNA skin sensitisation study, performed according to OECD 429 test guideline and GLP principles, Reaction mixture of 1,4-Butanediamine, 1,6-Hexanediamine and 1,4-Benzenedicarboxylic acid was considered not to be a skin sensitiser, as the SI appeared not to be ≥ 3 when tested up to and including 50% v/v.

Executive summary:

An LLNA skin sensitisation study was performed according to OECD 429 test guideline and GLP principles. Based on the results of a pre-screen test, the test concentrations were selected at 10%, 25% and 50% v/v. Reliable positive and negative controles were included. No irritation was observed in any of the animals. White staining of test substance remnants on the dorsal surface of the ears of all experimental animals between Day 1 and 4, did not hamper scoring for erythema. All auricular lymph nodes of the animals of the experimental and control groups were considered normal in size. No macroscopic abnormalities of the surrounding area were noted for any of the animals. No test substance related mortality occurred and no clinical signs of systemic toxicity were observed in the animals of the main study. Body weights and body weight gain of experimental animals remained in the same range as controls over the study period. Mean DPM/animal values for the experimental groups treated with test substance concentrations 10, 25 and 50% were 862, 614 and 1036 DPM, respectively. The mean DPM/animal value for the vehicle control group was 731 DPM. The SI values calculated for the substance concentrations 10, 25 and 50% were 1.2, 0.8 and 1.4, respectively. As the SI appeared not to be ≥ 3 when tested up to and including 50% v/v, Reaction mixture of 1,4-Butanediamine, 1,6-Hexanediamine and 1,4-Benzenedicarboxylic acid is considered not to be a skin sensitiser and does not have to be classified according to Regulation (EC) No 1272/2008 on the classification, labelling and packaging of substances and mixtures (including all amendments).