Adenosine 5'-(trihydrogen diphosphate), 2'-(dihydrogen phosphate), 5'→5'-ester with 3-(aminocarbonyl)-1-β-d-ribofuranosylpyridinium hydroxide, inner salt, disodium salt

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2011

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: study conducted under GLP and acc. to OECD guideline

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2011

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

Adenosine 5'-(trihydrogen diphosphate), 2'-(dihydrogen phosphate), 5'→5'-ester with 3-(aminocarbonyl)-1-β-d-ribofuranosylpyridinium hydroxide, inner salt, disodium salt

EC Number:

246-129-8

EC Name:

Adenosine 5'-(trihydrogen diphosphate), 2'-(dihydrogen phosphate), 5'→5'-ester with 3-(aminocarbonyl)-1-β-d-ribofuranosylpyridinium hydroxide, inner salt, disodium salt

Cas Number:

24292-60-2

Molecular formula:

C21H28N7O17P3.2Na

IUPAC Name:

Adenosine 5'-(trihydrogen diphosphate), 2'-(dihydrogen phosphate), 5'→5'-ester with 3-(aminocarbonyl)-1-β-d-ribofuranosylpyridinium hydroxide, inner salt, disodium salt

Details on test material:

- Physical state: white powder
- Storage condition of test material: in refrigerator (2-8 °C) in the dark

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source:Janvier, Le Genest-Isle, France
- Age at study initiation: 10- 11 weeks old
- Housing: labeled Makrolon cages
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21
- Humidity (%): 40 - 70
- Photoperiod (hrs dark / hrs light): 12

Study design: in vivo (LLNA)

Vehicle:

dimethyl sulphoxide

Concentration:

0, 10, 25 and 50% w/w

No. of animals per dose:

5

Details on study design:

MAIN STUDY ANIMAL ASSIGNMENT AND TREATMENT
-Three groups of five animals were treated with one test substance concentration per group. The highest test substance concentration was selected from the pre-screen test.
One group of five animals was treated with vehicle.

- 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. The SI is the ratio of the DPM/group compared to DPM/vehicle control group.
If the results indicate a SI = 3, the test substance may be regarded as a skin sensitizer.

The results were evaluated according to the GHS and the Regulation (EC) No 1272/2008.

Consideration was given to the EC3 value (the estimated test substance concentration that will give a SI =3) (Ref. 1).


TREATMENT PREPARATION AND ADMINISTRATION: The dorsal surface of both ears was topically treated (25 µL/ear) with the test substance concentration, at approximately the same time on each day. The concentrations were stirred with a magnetic stirrer immediately prior to dosing.

The control animals were treated in the same way as the experimental animals, except that the vehicle was administered instead of the test substance.

Positive control substance(s):

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

Results and discussion

In vivo (LLNA)

Results

Results 1

Key result

Parameter:

SI

Value:

1.2

Test group / Remarks:

substance concentration 10%

Results 2

Key result

Parameter:

SI

Value:

0.8

Test group / Remarks:

substance concentration 25%

Results 3

Key result

Parameter:

SI

Value:

1.1

Test group / Remarks:

substance concentration 50%

Results 4

Parameter:

other: disintegrations per minute (DPM)

Value:

>= 201 - <= 300

Test group / Remarks:

The mean DPM at 0, 10, 25 and 50% concentrations were: 247, 300, 201, 267 respectively

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

there was no indication that the test substance elicits an SI = 3 when tested up to 50%. b-NADP, Disodium salt was considered not to be a skin
sensitizer. It was established that the EC3 value (the estimated test substance concentration that will give a SI =3) (if any) exceeds 50%.

Executive summary:

Assessment of Contact Hypersensitivity to b-NADP, Disodium salt in the Mouse (Local Lymph Node Assay). The study was carried out based on the guidelines described in: OECD, Section 4, Health Effects, No.429 (2010),

Test substance concentrations selected for the main study were based on the results of a pre-screen test.

 In the main study, three experimental groups of five female/J mice were treated with test substance concentrations of 10, 25 or 50% w/w on three consecutive days, by open application on the ears. Five vehicle control animals were similarly treated, but with vehicle alone (Dimethyl sulphoxide).

After precipitating the DNAof the lymph node cells, radioactivity measurements were performed. The activity was expressed as the number of Disintegrations Per Minute (DPM) and a stimulation index (SI) was subsequently calculated for each group.

 

No irritation of the ears was observed in any of the animals examined.

All auricular lymph nodes of the animals of the experimental and control groups were considered normal in size, except for the nodes of most animals at 50% which appeared larger in size when compared to the other treated groups. No macroscopic abnormalities of the surrounding area were noted in any of the animals.

 

Mean DPM/animal values for the experimental groups treated with test substance concentrations 10, 25 and 50% were 300, 201 and 267 DPM respectively. The mean DPM/animal value for the vehicle control group was 247 DPM.

 

 The SI values calculated for the substance concentrations 10, 25 and 50% were 1.2, 0.8 and 1.1 respectively.

 

Since there was no indication that the test substance elicits an SI=3 when tested up to 50%,b-NADP, Disodium saltwas considered not to be a skin sensitizer. It was established that the EC3 value(the estimated test substance concentration that will give a SI =3)(if any) exceeds 50%.

 

The six-month reliability check withAlpha-hexylcinnamicaldehyde indicates that the Local Lymph Node Assay as performed at NOTOX is an appropriate model for testing for contact hypersensitivity.

 

Based on these results, b-NADP, Disodium salt would not be regarded as a skin sensitizer according to the recommendations made in the test guidelines. The test substance does not have to be classified and has no obligatory labelling requirement for sensitization by skin contact according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) of the United Nations (2007) and theRegulation (EC) No 1272/2008 on classification, labelling and packaging of substances and mixtures.