2-morpholinoethanesulphonic acid

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2016-09-14 to 2016-09-21

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2010

Deviations:

yes

Remarks:

Deviation in sample preparation without any presumed effect on the study

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2012

Deviations:

yes

Remarks:

Deviation in sample preparation without any presumed effect on the study

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:

2-(4-morpholinyl)ethansulfonic acid hydrate

Cas Number:

1266615-59-1

Molecular formula:

C6H13NO4S * xH2O

IUPAC Name:

2-(4-morpholinyl)ethansulfonic acid hydrate

Test material form:

solid: particulate/powder

In vivo test system

Test animals

Species:

mouse

Strain:

CBA/Ca

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: TOXI COOP ZRT. Cserkesz u. 90., 1103 Budapest, Hungary
- Females nulliparous and non-pregnant: yes
- Microbiological status of animals, when known: SPF
- Age at study initiation: 9 - 11 weeks
- Weight at study initiation: 17.9 - 21.0 g
- Fasting period before study: unknown
- Housing: group caging (4 mice/cage), Type II. Polypropylene / polycarbonate
- Diet: ad libitum, ssniff® Rat/Souris-Elevage E complete diet for rats and mice
- Water: ad libitum, tap water
- Acclimation period: 14 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22+/-3 °C
- Humidity (%): 30 - 70%
- Air changes (per hr): not available
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (LLNA)

Vehicle:

other: Pluronic

Concentration:

2.5, 5, 10%

No. of animals per dose:

4

Details on study design:

PRE-SCREEN TESTS:
- Compound solubility: yes (using seven recommended solvents)
- Irritation: no irritation was observed for the three concentration 2.5, 5 and 10% in a preliminary test
- Systemic toxicity: no toxicity was observed for the three concentration 2.5, 5 and 10% in a preliminary test
- Ear thickness measurements: no changes in ear thickness were observed for the three concentration 2.5, 5 and 10% in a preliminary test
- Erythema scores: all 0 for all concentrations, mice and time points (days 1, 2, 3, 4, 5, 6)

MAIN STUDY

ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: animals were assigned randomly achieving body weight homogeneity between groups
- Criteria used to consider a positive response: stimulation index of one concentration > 3

TREATMENT PREPARATION AND ADMINISTRATION: 25 µL of the three respective formulations (substance dissovled in Pluronic) were applied to the dorsal surface of each ear using a pipette

Positive control substance(s):

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

Statistics:

none

Results and discussion

Positive control results:

Stimulation index (SI) of (w/v) hexyl cinnamic aldehyde: 6.7

In vivo (LLNA)

Results

Results 1

Key result

Parameter:

SI

Value:

0.7

Test group / Remarks:

2.5%

Results 2

Key result

Parameter:

SI

Value:

2.3

Test group / Remarks:

5%

Results 3

Key result

Parameter:

SI

Value:

1.2

Test group / Remarks:

10%

Cellular proliferation data / Observations:

CELLULAR PROLIFERATION DATA
Disintegration per minute (per mouse (average)):
vehicle control: 772.8
2.5%: 513.0
5%: 1759.3
10%: 894.5

DETAILS ON STIMULATION INDEX CALCULATION: ratio of DPM/mouse of test concentrations and vehicle control

EC3 CALCULATION: not applicable

CLINICAL OBSERVATIONS: no irritation or other effects observed

BODY WEIGHTS: no treatment related effects

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of the present assay, the test item at the maximum feasible concentration of 10 % and also at concentrations of 5 % or 2.5 % (w/v) was shown to have no skin sensitization potential in the Local Lymph Node Assay.

Executive summary:

A study according OECD TG 429 was performed to evaluate the skin sensitising potential of the test item. A formulation evaluation and a Dose Range Finding test (DRF) were performed to find an appropriate vehicle and the maximum applicable concentration according to the relevant guidelines. Solubility of the test item in vehicles preferred in the LLNA was evaluated and concentration series of 100 %, 50 %, 25 %, 10 % etc. were used. The maximum attainable concentration (based on solubility) was 10 % (w/v) in aqueous 1 % (w/v) Pluronic®PE 9200 (Plu). According to results of the DRF, where no adverse effect was observed up to this maximum concentration, the test item was examined in the main test as 10 %, 5 % or 2.5 % (w/v) formulations in the selected vehicle of Plu. Appropriate positive control (alpha-Hexylcinnamaldehyde, HCA), furthermore two negative control groups dosed with the vehicles of the test and positive control groups, respectively, were employed. The positive control item (25 % (w/v) HCA in Acetone:Olive oil 4:1 (v/v) mixture, AOO) induced significant stimulation over the relevant control (SI = 6.7) thus confirming the validity of the assay. No mortality was observed during the main test. No significant, treatment related effect on body weights or any other sign of systemic toxicity were observed in any treatment group. No signs of irritation (monitored by erythema scoring) or any other local effect were observed at the treatment site (ears) in any treatment group. No significantly increased lymphoproliferation (indicated by an SI ≥ 3) compared to the relevant control (Plu) was noted for the test item at the applied test concentrations. The observed stimulation index values were 1.2, 2.3 and 1.7 at test item concentrations of 10 %, 5 % and 2.5 % (w/v), respectively. No significant dose-response relationship was observed. Accordingly, the substance was considered to be not a skin sensitizer.