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Administrative data

Description of key information

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records
Reference
Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2011
Reliability:
1 (reliable without restriction)
Qualifier:
according to
Guideline:
EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)
GLP compliance:
yes (incl. certificate)
Type of study:
mouse local lymph node assay (LLNA)
Species:
mouse
Strain:
other: CBA/J
Sex:
female
Vehicle:
propylene glycol
Concentration:
25, 50 and 100%
No. of animals per dose:
5
Key result
Parameter:
SI
Value:
ca. 2.1
Variability:
0.6
Test group / Remarks:
25% squalane
Key result
Parameter:
SI
Value:
ca. 2.8
Variability:
0.3
Test group / Remarks:
50% squalane
Key result
Parameter:
SI
Value:
ca. 2.8
Variability:
1.3
Test group / Remarks:
100% squalane
Key result
Parameter:
SI
Value:
ca. 2.3
Variability:
0.7
Test group / Remarks:
commercial AMYRIS squalane

Mean number of Proliferating Cells in the Lymph Nodes of each treatment group :

 Treatment  Vehicule  Mean total Cells in Node  Mean % BrdU + LNC  Mean Lymphocyte Proliferation ((BrdU+)
 Naive control  1771283  1.24  16710
 Vehicule control  -  1698250  1.64  11327
 Positive control  propylene glycol  12619900 1.74   221063
 25% Amyris squalane  propylene glycol  3052350 0.82   23468
 50% Amyris squalane   propylene glycol  3984800 0.83   32107
 100% Amyris squalane  -  4467433  1.22  46437
 100% commercial squalane  -  5635450  0.72  38087

Ear thickness (mm)

   Mean ear thickness (mm)        Change %   
 Treatment  Pre-dosing (day1) 48hrs (day3)   End of life (day6)  day3 - day1  day6 -day1
 Naive control  0.20  0.20  0.20  0
 Vehicule control  0.20  0.20  0.21  0  5
 Positive control  0.19  0.25  0.26  31.6  36.8
 25% Amyris squalane  0.20  0.20  0.20  0  0
 50% Amyris squalane  0.20  0.21  0.21  5  5
 100% Amyris squalane  0.19  0.19  0.20  0  5.3
 100% commercial squalane  0.19  0.21  0.20  10.5  5.3

Simulation index results:

Naive group : SI = 1.0 ± 0.5 Vehicule control group : SI = 1.0 ± 0.5 Positive control group : SI = 19.5 ± 7.1 25% studied squalane group : SI = 2.1 ± 0.6 50% studied squalane group : SI = 2.8 ± 0.3 100% studied squalane group : SI = 2.8 ± 1.3 100% commercial squalane : SI = 2.3 ± 0.7

Interpretation of results:
not sensitising
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
Topical application of the test article Squalane at 25%, 50% and 100% resulted in SI value less than 3; therefore this test article is not a dermal sensitizer in the Local Lymph Node Assay.
Executive summary:

The LLNA assay was conducted with seven separate groups of healthy female mice (5 animals per group). Three groups were treated with increasing concentrations of the test article (25, 50 and 100% squalane in propylene glycol). A vehicule control group was treated with propylene glycol and another group was treated with the positive control (25% HCA in propylene glycol). An additionnal control (commercial squalane) was supplied by the sponsor as a verification of similar toxicological response from a substance analogous to the test article but obtained from a different manufacturing procee. The naive control group was sham-treated to provide baseline value. The test article solutions, vehicule control and positive control were administratde by topical application to the dorsum of each ear, once daily for three consecutive days.

The mice were given an intraperitoneal injection of thymidine analog 5 -bromo-2'-deoxy-uridine (BrdU) five days following the initial dose and five hours prior to the sacrifice. At sacrifice the aurocular lymph nodes were isolated, single cell suspensions of lymph node cells (LNC) were generated and the LNC suspensions were analyzed by flow cytometry for BrdU incorporation and the total LNC. The amount of proliferation was determined as a measure of proliferation response of the local lymph node. The stimulation index (SI) was calculated by dividing the proliferative response of each test article treated aniaml by the mean proliferative response of the vehicule control group, or, for the 100% test article and 100% commercial squalane group, by the mean proliferative response of the naive group. The mean SI ± standard deviation was calculated for each group.Test article groups taht yielded an SI > 3 were characterized as sensitizing substances.

The SI of the positive control group was 19.5. The group SI values for the test article at 25, 50 and 100% were 2.1, 2.8 and 2.8 respectively. The group SI value for the commercial squalane was 2.3.

Topical application of the test article squalane at 25, 50 and 100% in propylene glycol resulted in SI values less than 3. Therefore, tis test article is not a dermal sensitizer in the Local Lymph Node Assay.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

The LLNA assay was conducted with seven separate groups of healthy female mice according to EU Method B.42. Topical application of the test article squalane at 25, 50 and 100% in propylene glycol resulted in SI values less than 3. Therefore, this test article is not a dermal sensitizer in the Local Lymph Node Assay.

Migrated from Short description of key information:

The LLNA assay was conducted with seven separate groups of healthy female mice according to EU Method B.42. Topical application of the test article squalane at 25, 50 and 100% in propylene glycol resulted in SI values less than 3. Therefore, this test article is not a dermal sensitizer in the Local Lymph Node Assay.

Justification for selection of skin sensitisation endpoint:

Recent study according EU Method and reliable without restriction

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification