Condensation products of N-(6-aminohexyl)-12-hydroxyoctadecanamide and sebacic acid

Endpoint summary

Description of key information

Due to water solubilty of 0.00013mg/l no depletion of Cysteine and Lysine was measured.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Reference 1

Endpoint:

skin sensitisation: in chemico

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2018

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 442C (In Chemico Skin Sensitisation: Direct Peptide Reactivity Assay (DPRA))

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

direct peptide reactivity assay (DPRA)

Positive control results:

Cinnamaldehyde

Key result

Run / experiment:

other: DPRA

Parameter:

other: DPRA

Value:

0

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Interpretation of results:

GHS criteria not met

Conclusions:

Due to water solubilty of 0.00013mg/l no depletion of Cysteine and Lysine was measured.

Reference 2

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

07 to 12 December 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

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)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Kyoeisha Chemical Co. Ltd. / Bx 6033175
- Expiration date of the lot/batch: March 17, 2019
- Purity test date: March 17, 2017

RADIOLABELLING INFORMATION
- Radiochemical purity: 98.94%
- Specific activity: 18000 mCi/mmole
- Locations of the label: no data
- Expiration date of radiochemical substance:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room Temperature (Ambient) in container and kept tightly closed and away from heat or sunlight.
- Stability under test conditions:
- Solubility and stability of the test substance in the solvent/vehicle:
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium:

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: None
- Preliminary purification step (if any):
- Final dilution of a dissolved solid, stock liquid or gel:
- Final preparation of a solid:

FORM AS APPLIED IN THE TEST (if different from that of starting material)

TYPE OF BIOCIDE/PESTICIDE FORMULATION (if applicable)

OTHER SPECIFICS:
- measurement of pH, osmolality, and precipitate in the culture medium to which the test chemical is added:
- other information:

Species:

mouse

Strain:

CBA:J

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Commercial laboratory animal supplier.
- Females nulliparous and non-pregnant: yes
- Microbiological status of animals, when known: no data
- Age at study initiation: 10-12 weeks
- Weight at study initiation: 19-9 to 27.4 g
- Housing: Solid floor polypropylene mice cages (size: 290 mm x 220 mm x 140 mm). Each cage is fitted with a top grill having provision for keeping rodent pellet feed and water bottles. The bottom of the cages is layered with clean sterilized rice husk as bedding material.
- Diet : Teklad Certified Global High Fiber Rat/Mice Feed manufactured by Envigo, USA, was provided ad libitum.
- Water: UV sterilised water (Reverse Osmosis water filtration system) was provided ad libitum.
- Acclimation period: 8 days
- Indication of any skin lesions: no data

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 to 23 °C
- Humidity (%): 58 to 66%
- Air changes (per hr): Minimum 15 air changes/hour
- Photoperiod (hrs dark / hrs light): The photoperiod was 12 h artificial light and 12 h darkness, light hours being 06:00 – 18:00 h (photoperiod maintained through an automatic timer).
- IN-LIFE DATES: From: To:

Vehicle:

dimethylformamide

Concentration:

25%

No. of animals per dose:

5

Details on study design:

PRE-SCREEN TESTS:
- Compound solubility: The test item was found to be insoluble in acetone: olive oil (4:1 v/v), methyl ethyl ketone (MEK), propylene glycol (PG), dimethyl sulfoxide (DMSO) and 1% pluronic L-92 up to 25% (w/v). However the test item did form a homogeneous suspension in dimethylformamide (DMF) up to 25% (w/v), therefore, based on the results of the solubility tests and in consultation with the Sponsor, dimethylformamide (DMF) was selected as the vehicle.
- Irritation: none
- Systemic toxicity: none
- Ear thickness measurements: Yes
- Erythema scores: none

MAIN STUDY

ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: LLNA
- Criteria used to consider a positive response: The proliferative response of lymph nodes from each mouse was expressed as the number of radioactive disintegrations per minute (DPM), calculated by subtracting the background DPM (measured using a 1 mL aliquot of 5% TCA).
The DPM/mouse, along with an appropriate measure of inter-animal variability (i.e., mean ± standard deviation), were calculated for each test group and vehicle and positive control groups. Final results were expressed as the Stimulation Index (SI) which is calculated as a ratio of the mean DPM of the test group divided by mean DPM of the vehicle control group.


TREATMENT PREPARATION AND ADMINISTRATION: Three groups (G2 to G4) were treated topically for three consecutive days (days 0, 1 and 2) on the dorsal surface of both ears (25 L/ear) using a calibrated micropipette at concentrations of 5%, 10% and 25% (w/v) N, Nʹ-bis {6-[12-(hydroxy) octadecanoylamino] hexyl} decanediamide in dimethlformamide, respectively. Mice from the vehicle control group (G1) and positive control group (G5) were handled in the same manner but received 25 L/ear of dimethylformamide and 25% (v/v) a-Hexylcinnamaldehyde in dimethylformamide, respectively.
On day 5, all mice from the vehicle control, positive control and all the treatment groups were injected with 250 µL of sterile phosphate buffered saline (PBS) containing 20.93 µCi of 3H-methyl thymidine via the tail vein.

Positive control substance(s):

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

Positive control results:

The SI of 7.53 obtained for the positive control, -Hexylcinnamaldehyde, showed a greater than a three-fold increase over the control value indicating a positive response in agreement with the historical control for this known weak sensitiser. This confirmed the reliability of this test procedure.

Key result

Parameter:

SI

Value:

1

Test group / Remarks:

G1- Vehicle (DMF)

Key result

Parameter:

SI

Value:

1.07

Test group / Remarks:

G2 - 5% w/v in DMF

Key result

Parameter:

SI

Value:

1.22

Test group / Remarks:

G3 - 10% w/v in DMF

Key result

Parameter:

SI

Value:

1.74

Test group / Remarks:

G4 - 25% w/v in DMF

Key result

Parameter:

SI

Value:

7.53

Test group / Remarks:

G5 - 25% v/v HCA in DMF

Cellular proliferation data / Observations:

CELLULAR PROLIFERATION DATA Incorporation of 3H-methyl thymidine was measured by β-scintillation counting as Disintegrations Per Minute (DPM) for each mouse and expressed as DPM/mouse. The total radioactivity of each sample was counted using LSA (Liquid Scintillation Analyser) after
30 minutes of mixing with scintillation fluid and the required quench corrections made.

DETAILS ON STIMULATION INDEX CALCULATION The proliferative response of lymph nodes from each mouse was expressed as the number of radioactive disintegrations per minute (DPM), calculated by subtracting the background DPM (measured using a 1 mL aliquot of 5% TCA).
The DPM/mouse, along with an appropriate measure of inter-animal variability (i.e., mean ± standard deviation), were calculated for each test group and vehicle and positive control groups. Final results were expressed as the Stimulation Index (SI) which is calculated as a ratio of the mean DPM of the test group divided by mean DPM of the vehicle control group.

EC3 CALCULATION If the test item produces a SI  3 in the LLNA, it is considered positive for contact sensitisation potential and therefore, an EC3 is determined. EC3 value (theoretical concentration resulting in a SI value of 3) is determined by linear interpolation of points on the dose-response curve, immediately above and below the 3-fold threshold (Basketter et al., 1999). The equation used for calculation of EC3 was:
EC3 = c + [(3 - d)/(b - d)] x (a - c)
Where a = the lowest concentration giving stimulation index > 3; b = the actual stimulation index caused by a; c = the highest concentration failing to produce a stimulation index of 3; and d = the actual stimulation index caused by c.

CLINICAL OBSERVATIONS: No clinical signs were observed in any mouse from the vehicle control, positive control or any treated group at 5%, 10% or 25% (w/v) N, Nʹ-bis {6-[12-(hydroxy) octadecanoylamino] hexyl} decanediamide in dimethylformamide .
No erythema was observed in any treated mouse at 5%, 10% and 25% (w/v) N, Nʹ-bis {6-[12-(hydroxy) octadecanoylamino] hexyl} decanediamide in dimethylformamide on day 0 to day 5. Very slight erythema was observed in the positive control group treated with 25% HCA (during days 1 to 4) in all mice (5/5 mice).

BODY WEIGHTS The mean body weight of positive control and N, Nʹ-bis {6-[12-(hydroxy) octadecanoylamino] hexyl} decanediamide treated mice was comparable to that of the vehicle control group.

Interpretation of results:

GHS criteria not met

Conclusions:

Based on the results of this study, the classification for N, Nʹ-bis {6-[12-(hydroxy) octadecanoylamino] hexyl} decanediamide is as follows:
Globally Harmonized System of Classification and Labelling of Chemicals (GHS 2017): Not Classified as a Skin Sensitiser

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Due to water solubilty of 0.00013mg/l no depletion of Cysteine and Lysine was measured. This substance is not classified.

Based on the results of the LLNA study, the classification for N, Nʹ-bis {6-[12-(hydroxy) octadecanoylamino] hexyl} decanediamide is as follows:

Globally Harmonized System of Classification and Labelling of Chemicals (GHS 2017): Not Classified as a Skin Sensitiser