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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
From: 7 September 1992 To: 9 October 1992
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP Guideline study.
Cross-referenceopen allclose all
Reason / purpose for cross-reference:
reference to same study
Reason / purpose for cross-reference:
reference to other study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1992
Report date:
1992

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
no
Principles of method if other than guideline:
Not applicable.
GLP compliance:
yes (incl. QA statement)
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
The guinea pig maximisation test was the default method of assessment at the time the study was undertaken.

Test material

Constituent 1
Chemical structure
Reference substance name:
A mixture of: tetrasodium-phosphonoethane-1,2-dicarboxylate; hexasodium-phosphonobutane-1,2,3,4-tetracarboxylate
EC Number:
410-800-5
EC Name:
A mixture of: tetrasodium-phosphonoethane-1,2-dicarboxylate; hexasodium-phosphonobutane-1,2,3,4-tetracarboxylate
Cas Number:
143239-08-1
Molecular formula:
There is no molecular formula available, as the reference substance is a multi- constituent reaction mass. The molecular formulae of the constituents are documented in section 1.2.
IUPAC Name:
Reaction mass of tetrasodium phosphonoethane-1,2-dicarboxylate and hexasodium-phosphonobutane-1,2,3,4-tetracarboxylate
Details on test material:
- Physical state: white powder
- Storage condition of test material: room temperature under silica gel

In vivo test system

Test animals

Species:
guinea pig
Strain:
Dunkin-Hartley
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: David Hall Limited, Burton-on-Trent, Staffordshire, U.K.
- Age at study initiation: 8-12 weeks old
- Weight at study initiation: 300-366 g
- Housing: up to 3 per cage
- Diet : ad libitum
- Water : ad libitum
- Acclimation period: at least 5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-22
- Humidity (%): 51-75
- Air changes (per hr): 15
- Photoperiod : 12 hrs dark / 12 hrs light


IN-LIFE DATES: From: 7 September 1992 To: 9 October 1992

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
intradermal and epicutaneous
Vehicle:
water
Concentration / amount:
Intradermal induction: 1 % (w/v) in distilled water
Topical induction: 75 % (w/v) in distilled water
Topical challenge: 50 % and 25 % (w/w) in distilled water
Challengeopen allclose all
Route:
epicutaneous, semiocclusive
Vehicle:
water
Concentration / amount:
Intradermal induction: 1 % (w/v) in distilled water
Topical induction: 75 % (w/v) in distilled water
Topical challenge: 50 % and 25 % (w/w) in distilled water
No. of animals per dose:
20 (test)
10 (control)
Details on study design:
RANGE FINDING TESTS:
- For intradermal induction: 1% was selected for the main study considering as the highest concentration that did not cause local necrosis, ulceration or systemic toxicity
- For Topical application: 75% was selected for the main study considering as the highest concentration producing only mild to moderate dermal irritation after a 48-hour occlusive exposure
- For Topical Challenge: 25% and 75% were selected for the main study considering as the highest non-irritant concentration.
MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 2
- Exposure period: Day 0 and Day 7
- Site: shoulder region
- Concentrations: 1 % (intradermal), 75 % (epidermal)

Intradermal injection/ day 0
3 pairs of intradermal injections (0.1 ml on each side of the mid-line) were made in an area approximately 40 mm x 60 mm on the shoulder region.
Test animals:
1) Freund's Complete Adjuvant plus distilled water in the ratio 1:1
2) a 1 % (w/v) dilution of test material in distilled water
3) a 1 % (w/v) dilution of test material in a 1:1 preparation of Freund's Complete Adjuvant plus distilled water

Control animals:
1) Freund's Complete Adjuvant plus distilled water in the ratio 1:1
2) distilled water
3) Freund's Complete Adjuvant plus distilled water in the ratio 1:1

Epidermal applications/day 7
One week later (Day 7), the same area on the shoulder region used previously for intradermal injections was clipped again and treated with a topical application of the test material formulation (75 % w/w in distilled water). The test material formulation (0.2-0.3 ml) was applied on filter paper (WHATMAN No.4: approximate size 40 mm x 20 mm) which was held in place by a strip of surgical adhesive tape (BLENDERM: approximate size 60 mm x 25 mm) and covered with an overlapping lenght of aluminium foil. The patch and foil were further secured by a strip of elastic adhesive bandage (ELASTOPLAST: approximate size 250 mm x 35 mm) wound in a double layer around the torso of each animal. This occlusive dressing was kept in place for 48 hours.

Erythematous reactions were quantified one and twenty-four hours following removal of the patches.

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: day 21
- Exposure period: 24 hours
- Test groups and Control group: a quantity of 0.1-0.2 ml of the test material formulation (50 % w/w in distilled water) was a^pplied to the shorn right flank of each animal on a square of filter paper which was held in place by a strip of surgical adhesive tape. To ensure that the maximum non-irritant concentration was used at challenge, the test material at a concentration of 25% (w/w) in distilled water was also similarly applied to a separate skin site on the right shorn flank. The vehicle alone was similarly applied to the left shorn flank.
- Site: right flank (test material), left flank (vehicle)
- Concentrations: 50 and 25 %
- Evaluation (hr after challenge): 24, 48 and 72 hours


Challenge controls:
no data
Positive control substance(s):
not specified

Study design: in vivo (LLNA)

Statistics:
None

Results and discussion

Positive control results:
no data

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
test chemical
Dose level:
50 %
No. with + reactions:
10
Total no. in group:
19
Clinical observations:
no data
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 50 %. No with. + reactions: 10.0. Total no. in groups: 19.0. Clinical observations: no data.
Reading:
2nd reading
Hours after challenge:
48
Group:
test chemical
Dose level:
50 %
No. with + reactions:
7
Total no. in group:
19
Clinical observations:
no data
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 50 %. No with. + reactions: 7.0. Total no. in groups: 19.0. Clinical observations: no data.
Reading:
1st reading
Hours after challenge:
24
Group:
test chemical
Dose level:
25 %
No. with + reactions:
1
Total no. in group:
19
Clinical observations:
no data
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 25 %. No with. + reactions: 1.0. Total no. in groups: 19.0. Clinical observations: no data.
Reading:
2nd reading
Hours after challenge:
48
Group:
test chemical
Dose level:
25 %
No. with + reactions:
2
Total no. in group:
19
Clinical observations:
no data
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 25 %. No with. + reactions: 2.0. Total no. in groups: 19.0. Clinical observations: no data.

Any other information on results incl. tables

Table 7.4.1/1: Reaction at challenge at 24 h and 48 h in negative control group and test group (25%)

 

Animal

number

Reaction at challenge

24 h

48 h

72 h

Control group

 

21

0

0

0

 

22

0

0

0

 

23

0

0

0

 

24

0

0

0

 

25

0

0

0

 

26

0

0

0

 

27

0

0

0

 

28

0

0

0

 

29

0

0

0

 

30

0

0

0

 

Test group (25%)

 

 

 

 

 

 

1

0

0

0

 

2

0

0

0

 

3

0

0

0

 

4

0

0

0

 

5

0

0

0

 

6

0

0

0

 

7

0

0

0

 

8

0

0

0

 

9

0

0

0

 

10

0

0

0

 

11

0

0

0

 

12

0

0

0

 

13

0

0

0

 

14

0

0

0

 

15

0

0

0

 

16

0

0

0

 

17

1

1

0D

 

18

0

1

0

 

19

-

-

-

 

20

0

0

0

 

 

- = no data; animal found dead day 14

D = Desquamation

R = extended reaction

Table 7.4.1/2: Reaction at challenge at 24 h and 48 h in negative control group and test group (50%)

 

Animal

number

Reaction at challenge

24 h

48 h

72 h

Control group

 

21

0

0

0

 

22

0

0

0

 

23

0

0

0

 

24

0

0

0

 

25

0

0

0

 

26

0

0

0

 

27

0

0

0

 

28

0

0

0

 

29

0

0

0

 

30

0

0

0

 

Test group (50%)

 

 

 

 

 

 

1

1

1

0

 

2

1

1

0

 

3

1

1

0

 

4

1

1

0

 

5

0

0

0

 

6

1

1

0

 

7

0

0

0

 

8

1R

1R

0 D

 

9

1

0

0

 

10

1

1

0

 

11

1

0

0

 

12

0

0

0

 

13

0

0

0 D

 

14

0

0

0

 

15

1

0

0

 

16

0

0

0

 

17

0

1

0

 

18

0

1

0

 

19

-

-

-

 

20

0

0

0

 

 

- = no data; animal found dead day 14

D = Desquamation

R = extended reaction

Applicant's summary and conclusion

Interpretation of results:
sensitising
Remarks:
Migrated information
Conclusions:
Under the conditions of this test, ITC 288 produced a 58 % (11/19) sensitisation rate and was classified in category 1B, H317 ( May cause an allergic skin reaction) according to the CLP regulation (1272/2008) and as a sensitiser to guinea pig skin (Xi, R43) according to the Directive 67/548/EEC.
Executive summary:

In a dermal sensitisation study (Tuffnell PP, 1992), female albino Dunkin-Hartley guinea pigs (20 tested, 10 control) were used to test the skin contact sensitisation potential of ITC 288. The method of Guinea pig maximisation test was used. The concentrations of the test material were 1% for the intradermal induction, 75 % for the topical induction and 50 and 25 % for the topical challenge. one test animal was found dead on day 14. The cause of death was not determined but the absence of this animal was considered not to affect the purpose or integrity of the study. Scattered mild redness and moderate and diffuse redness were elicited by the test material after topical induction. Other adverse reactions noted were bleeding, dried blood and small superficial scattered scabs. After topical challenge (50 % of test material), positive skin responses were noted at the test sites of ten test animals at the 24 -hour observation and persisted in seven test animals at the 48 -hour observation. The reaction extended beyond the treatment site of one test animal at the 24 and 48 -hour observations. Desquamation was noted at the test sites of two test animals at the 72 -hour observation; according to Draize's scale and Magnusson and Kligman's scale this local effect should not be considered as an positive reaction. No adverse reactions were noted at the test sites of control animals at the 24, 48 and 72 -hour observations. After topical challenge (25 % of test material), a positive skin response was noted at the test sites of one test animal at the 24 and 48 -hour observations. A positive reponse developed at the test site of one more test animal at the 48 -hour observation. Desquamation was noted at the test site of one test animal at the 72 -hour observation. No adverse reactions were noted at the test sites of control animals at the 24, 48 and 72 -hour observations. It should be noted that desquamation observed for two animals at 72 -hour post exposure were discounted for the calculation of the sensitisation index. Initially the study report mentioned 12 animals with positive reactions, and after re-evaluation of the data only 11 showed clear skin sensitisation effect; the latest animal exhibited only desquamation at 72 -hours post exposure without any previous local effects.

Under the conditions of this test, ITC 288 produced a 58 % (11/19) sensitisation rate and was classified in category 1B, H317 ( May cause an allergic skin reaction) according to the CLP regulation (1272/2008) and as a sensitiser to guinea pig skin (Xi, R43) according to the Directive 67/548/EEC.

This skin sensitisation study is classified as acceptable. It satifies the guideline requirement for a skin sensitisation in the guinea pig.