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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
06 - 30 April 2012
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP study conducted in compliance with OECD Guideline 429 without any deviation.
Cross-referenceopen allclose all
Reason / purpose:
reference to same study
Reason / purpose:
reference to other study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012
Report Date:
2012

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Deviations:
no
Principles of method if other than guideline:
Not applicable
GLP compliance:
yes (incl. certificate)
Type of study:
mouse local lymph node assay (LLNA)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid: viscous
Details on test material:
- Name of test material (as cited in study report): PI2080
- Physical state: Limpid amber highly viscous liquid
- Analytical purity: 97 ± 3 %
- Lot/batch No.: 11GP0077
- Date of receipt: 10 February 2012
- Expiration date of the lot/batch: January 2014
- Storage condition of test material: Stored at room temperature and protected from light

In vivo test system

Test animals

Species:
mouse
Strain:
CBA:JN
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Janvier, Le Genest-Saint-Isle, France.
- Age at study initiation: Preliminary test - Approximately 11 weeks; Main test - Approximately 8 weeks
- Weight at study initiation: Main test - 19.5 g (18.6-21.3 g)
- Housing: Animals were housed by groups of two (preliminary test) or four (main test) in polycarbonate cages containing autoclaved sawdust. In the main test, on Day 6 before the [3H] methyl-thymidine (3H-TdR) injections, the animals were individually housed in disposable crystal polystyrene cages.
- Diet: SSNIFF R/M-H pelleted maintenance diet (SSNIFF Spezialdiäten GmbH, Soest, Germany), ad libitum
- Water: Tap water (filtered using a 0.22 µm filter), ad libitum
- Acclimation period: 6 or 7 days

ENVIRONMENTAL CONDITIONS
- Temperature: 22 ± 2 °C
- Humidity: 50 ± 20 %
- Air changes: Approximately 12 cycles/hour of filtered, non-recycled air
- Photoperiod: 12 h dark / 12 h light

Study design: in vivo (LLNA)

Vehicle:
acetone/olive oil (4:1 v/v)
Concentration:
50%
No. of animals per dose:
4 females per dose
Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)

Results and discussion

Positive control results:
Stimulation index for α-hexylcinnamaldehyde at 25 % v/v was 6.72 and classified as a sensitiser.

In vivo (LLNA)

Resultsopen allclose all
Key result
Parameter:
SI
Value:
0.72
Test group / Remarks:
0.25%
Key result
Parameter:
SI
Value:
0.81
Test group / Remarks:
0.5%
Key result
Parameter:
SI
Value:
1.59
Test group / Remarks:
1%
Key result
Parameter:
SI
Value:
1.49
Test group / Remarks:
2.5%
Key result
Parameter:
SI
Value:
2
Test group / Remarks:
5%

Any other information on results incl. tables

Table 7.4.1/1: Results of skin sensitization

Treatment and concentrations

No. of nodes per group

dpm per group

dpm per node

Stimulation index (SI)

Increase in ear thickness (% between Day 1 and Day 6)

Irritation level

EC3 value

Vehicle

8

2462

307.75

-

11.00

-

-

0.25 %

8

1766

220.75

0.72

10.89

II

NA

0.5 %

8

1985

248.13

0.81

9.38

I

1 %

8

3925

490.63

1.59

11.22

II

2.5 %

8

3672

459.00

1.49

10.00

II

5 %

8

4913

614.13

2.00

16.33

II

α-hexylcinnamaldehyde 25 %

8

16538

2067.25

6.72

-

-

-

                            

dpm = disintegrations per minute

I = non-irritant (increase in ear thickness < 10 %)

EC3 value = theoretical concentration resulting in a SI value of 3

stimulation index = dpm of treated group / dpm of control group

- No mortality and no clinical signs were observed during the observation period.

- Body weight change of test item-treated animals was similar to that of control animals.

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
Under these test conditions, test item, PI2080 is not classified as sensitizing to the skin according to the Annex VI to the Directive 67/548/EEC and the CLP Regulation (EC) N° (1272-2008).
Executive summary:

In a local lymph node assay performed according to OECD Guideline 429 and in compliance with GLP, groups of CBA/J mice (4 females/dose) were topically applied with 25 µL of test item, PI2080 at concentrations of 0.25, 0.5, 1, 2.5 and 5 % to the dorsal surface of both ears for three consecutive days. Vehicle control group of four females received the vehicle (acetone/olive oil (4/1; v/v)). From Days 1 to 3 then on Day 6, the thickness of the left ear of each animal was measured, except in animals of the positive control group, and the local reactions were recorded. After 2 rest days, on Day 6, the animals received a single intravenous injection of tritiated methyl thymidine (3H-TdR). Approximately 5 h later, the animals were sacrificed and the auricular lymph nodes were excised. The proliferation of lymphocytes in the lymph node draining the application site was measured by incorporation of 3H-TdR. The results were expressed as disintegrations per minute (dpm) per group; dpm/node and the obtained values were used to calculate Stimulation Indices (SI). Animals were observed for mortality, clinical signs and body weight during the study. The test concentrations for the main study were determined from a preliminary study (5, 10, 25 and 50 %) using two animals per exposure.

No mortality and no clinical signs were observed during the observation period. Body weight of the animals was unaffected by the test item treatment. No notable increase in ear thickness or irritation was observed at any tested concentrations. No notable lymphoproliferation was noted with the test item at any tested concentrations. DPM per group for vehicle, 0.25, 0.5, 1, 2.5 and 5 % were 2462, 1766, 1985, 3925, 3672 and 4913, respectively. DPM per node for vehicle, 0.25, 0.5, 1, 2.5 and 5 % were 307.75, 220.75, 248.13, 490.63, 459.00 and 614.13, respectively. Stimulation index for 0.25, 0.5, 1, 2.5 and 5 % were 0.72, 0.81, 1.59, 1.49 and 2.00, respectively. Positive control (α-hexylcinnamaldehyde, 25%) exhibited evidence of sensitisation indicating the validity of the study. In this study, test item, PI2080 is not a skin sensitizer in mice.

Under these test conditions, test item PI2080 is not classified as sensitizing to the skin according to the Annex VI to the Directive 67/548/EEC and the CLP Regulation (EC) N° (1272-2008).