sodium 3-((2,3-dicyanophenyl)sulfonyl)propane-1-sulfonate

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Remarks:

existing study

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Experimental test phase 2013-12-05 to 2013-12-18

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Meets the criteria for classification as reliable without restriction according to Klimisch et al (1997)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2014

Report date:

2014

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

sodium 3-((2,3-dicyanophenyl)sulfonyl)propane-1-sulfonate

EC Number:

696-126-4

Cas Number:

886592-17-2

Molecular formula:

C11H9N2O5S2Na

IUPAC Name:

sodium 3-((2,3-dicyanophenyl)sulfonyl)propane-1-sulfonate

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

In vivo test system

Test animals

Species:

mouse

Strain:

other: CBA/Ca (CBA/CaOlaHsd)

Sex:

female

Details on test animals and environmental conditions:

Female CBA/Ca (CBA/CaOlaHsd) strain mice were supplied by Harlan Laboratories UK Ltd., Oxon, UK. On receipt the animals were randomly allocated to cages. The animals were nulliparous and non pregnant. After an acclimatization period of at least five days the animals were selected at random and given a number unique within the study by indelible ink marking on the tail and a number written on a cage card. At the start of the study the animals were in the weight range of 15 to 23 g, and were eight to twelve weeks old.

The animals were individually housed in suspended solid floor polypropylene cages furnished with softwood woodflakes. Free access to mains tap water and food (2014C Teklad Global Rodent diet supplied by Harlan Laboratories UK Ltd., Oxon, UK) was allowed throughout the study.

The temperature and relative humidity were controlled to remain within target ranges of 19 to 25 ºC and 30 to 70%, respectively. Any occasional deviations from these targets were considered not to have affected the purpose or integrity of the study. The rate of air exchange was approximately fifteen changes per hour and the lighting was controlled by a time switch to give twelve hours continuous light (06.00 to 18.00) and twelve hours darkness.

The animals were provided with environmental enrichment items which were considered not to contain any contaminant of a level that might have affected the purpose or integrity of the study.

Study design: in vivo (LLNA)

Vehicle:

dimethyl sulphoxide

Concentration:

25%, 10% and 5% w/w in dimethyl sulphoxide

No. of animals per dose:

4

Details on study design:

Groups of four mice were treated with the test item at concentrations of 25%, 10% or 5% w/w in dimethyl sulphoxide. The preliminary screening test suggested that the test item would not produce systemic toxicity or excessive local skin irritation at the highest suitable concentration. The mice were treated by daily application of 25 µL of the appropriate concentration of the test item to the dorsal surface of each ear for three consecutive days (Days 1, 2, 3). The test item formulation was administered using an automatic micropipette and spread over the dorsal surface of the ear using the tip of the pipette.

A further group of four mice received the vehicle alone in the same manner.

Five days following the first topical application of the test item or vehicle (Day 6) all mice were injected via the tail vein with 250 µL of phosphate buffered saline (PBS) containing 3H methyl thymidine (3HTdR: 80 µCi/mL, specific activity 2.0 Ci/mmoL, ARC UK Ltd) giving a total of 20 µCi to each mouse.

Termination: Five hours following the administration of 3HTdR all mice were killed by carbon dioxide asphyxiation. The draining auricular lymph nodes from the four mice were excised and pooled for each experimental group. For each group 1 mL of PBS was added to the pooled lymph nodes.

Preparation of Single Cell Suspension: A single cell suspension of pooled lymph node cells was prepared by gentle mechanical disaggregation through a 200 mesh stainless steel gauze. The lymph node cells were rinsed through the gauze with 4 mL of PBS into a petri dish labeled with the study number and dose concentration. The lymph node cell suspension was transferred to a centrifuge tube. The petri dish was washed with an additional 5 mL of PBS to remove all remaining lymph node cells and these were added to the centrifuge tube. The pooled lymph node cells were pelleted at 1400 rpm (approximately 190 g) for ten minutes. The pellet was re-suspended in 10 mL of PBS and re pelleted. To precipitate out the radioactive material, the pellet was re-suspended in 3 mL of 5% Trichloroacetic acid (TCA).

Determination of 3HTdR Incorporation: After approximately eighteen hours incubation at approximately 4 °C, the precipitates were recovered by centrifugation at 2100 rpm (approximately 450 g) for ten minutes, re suspended in 1 mL of TCA and transferred to 10 mL of scintillation fluid (Optiphase 'Trisafe'). 3HTdR incorporation was measured by  scintillation counting. The "Poly Q™" vials containing the samples and scintillation fluid were placed in the sample changer of the scintillator and left for approximately twenty minutes. The purpose of this period of time in darkness was to reduce the risk of luminescence, which has been shown to affect the reliability of the results. After approximately twenty minutes, the vials were shaken vigorously. The number of radioactive disintegrations per minute was then measured using the Beckman LS6500 scintillation system (Beckman Instruments Inc, Fullerton, CA, USA).

Results and discussion

In vivo (LLNA)

Results

Results 1

Key result

Parameter:

SI

Value:

ca. 1.23

Test group / Remarks:

5% w/w in dimethyl sulfoxide

Results 2

Key result

Parameter:

SI

Value:

ca. 1.13

Test group / Remarks:

10% w/w in dimethyl sulfoxide

Results 3

Key result

Parameter:

SI

Value:

ca. 1.4

Test group / Remarks:

25% w/w in dimethyl sulfoxide

Any other information on results incl. tables

Disintegrations per Minute, Disintegrations per Minute/Node and Stimulation Index

Concentration (%w/w) in dimethyl sulphoxide	dpm	dpm/Nodea	Stimulation Indexb	Result
Vehicle	21401.34	2675.17	na	na
5	26338.66	3292.33	1.23	Negative
10	24229.04	3028.63	1.13	Negative
25	29910.19	3738.77	1.40	Negative

 

dpm=Disintegrations per minute

a=          Disintegrations per minute/node obtained by dividing the disintegrations per minute value by 8 (total number of lymph nodes)

b=          Stimulation Index of 3.0 or greater indicates a positive result

na =        Not applicable

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The test item was considered to be a non-sensitizer under the conditions of the test.

The test item does not meet the criteria for classification according to the Regulation (EC) No 1272/2008, relating to the Classification, Labelling and Packaging of Substances and Mixtures.

Executive summary:

Introduction

The study was performed to assess the skin sensitization potential of the test item in the CBA/Ca strain mouse following topical application to the dorsal surface of the ear. This study was designed to be compatible with the procedures indicated by the following internationally accepted guidelines and recommendations:

 

·     OECD Guideline for the Testing of Chemicals No. 429 "Skin Sensitization: Local Lymph Node Assay" (adopted 22 July 2010)

·     Method B42 Skin Sensitization (Local Lymph Node Assay) of Commission Regulation (EC) No. 440/2008

 Results & Conclusions

The test item was considered to be a non-sensitizer under the conditions of the test. The test item does not meet the criteria for classification according to the Regulation (EC) No 1272/2008, relating to the Classification, Labelling and Packaging of Substances and Mixtures.