3,5-diethyl-1,2-dihydro-1-phenyl-2-propylpyridine

Skin sensitisation

Some information in this page has been claimed confidential.

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

6 Nov 2017-April 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2600 (Skin Sensitisation)

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Test material form:

liquid

Details on test material:

Purity > 84%, yellow to amber liquid. Lot # 0000152614. Expiry date 06 March 2018.

Specific details on test material used for the study:

The substance was stored at room temperature. Composition of test substance was reported to be [composition]. The test substance appeared as [description of substance] with [odour of substance]. The substance was expected to be stable for the duration of testing. The expiration date of the test substance was [expiration date].

In vivo test system

Test animals

Species:

mouse

Strain:

CBA:J

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source:
- Females (if applicable) nulliparous and non-pregnant:
- Microbiological status of animals, when known:
- Age at study initiation: 11-12 weeks
- Weight at study initiation:
- Housing: The animals were individually housed in plastic solid bottom cages during the dosing and resting phase of the study. After final weighing until sacrifice, animals were housed in their respective dose groups in plastic cages with bedding. Bedding in the plastic, solid bottom cages was changed at least once per week. Enrichment (e.g., nesting material) was placed in each cage. All caging conformed to the size recommendations in the most recent Guide for the Care and Use of Laboratory Animals (Natl. Res. Council, 2011).
- Diet (e.g. ad libitum): [Food source], ad libitum
- Water (e.g. ad libitum): Filtered tap water ad libitum
- Acclimation period: 21 days
- Indication of any skin lesions: None

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-23 ˚C
- Humidity (%): 41-56%
- Air changes (per hr): 13. Airflow measurements were evaluated regularly and records are kept on file at testing facility.
- Photoperiod (hrs dark / hrs light): 12-hour light/dark cycle
- IN-LIFE DATES: Not reported

Study design: in vivo (LLNA)

Vehicle:

acetone/olive oil (4:1 v/v)

Concentration:

Dose range finder: 100%, 50%, 25%, and 10%

No. of animals per dose:

Preliminary Irritation (4 groups): 2 per group
Test (3 groups): 5 per group
Vehicle (Negative) Control: 5
Positive Control: 5

Positive control substance(s):

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

Statistics:

The treated groups and negative vehicle control group were compared using a One-Way Analysis of Variance (ANOVA), followed by comparison of the treated groups to control by Dunnett’s t-test for multiple comparisons (INSTAT Biostatistics, Graph Pad Software, San Diego, CA). Outlier analysis was conducted using Grubbs (1969).

Results and discussion

Positive control results:

Valid

In vivo (LLNA)

Results

Key result

Parameter:

EC3

Remarks on result:

not determinable because of methodological limitations

Remarks:

All animals died

Any other information on results incl. tables

Test was not continued due to the lethality of the substance to mice. In dose-range finding studies in CD1 mice (one per dose), the substance was applied to the dorsal aspect of the ears at concentrations of 100% in AOO, 50%, and 10%.  Animals either died or were killed in extremis within 24 h.  The test was discontinued as it was felt that this extreme and perhaps idiosyncratic response prevented the test system from accurately predicting the sensitisation potential for humans.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The test substance was attempted to be tested for dermal sensitisation in OECD Guideline 429 (murine LLNA). In dose-range finding studies in CD1 mice (one per dose), the substance was applied to the dorsal aspect of the ears at concentrations of 100% in AOO, 50%, and 10%. Animals either died or were killed in extremis within 24 h. The test was discontinued.