Aspartic acid, N-[3-(trimethoxysilyl)propyl]-, 1,4-diethyl ester

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

2003

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

- modification: in addition, measurements of ear swelling and ear weight were done to discriminate the irritating potential from the sensitizing potential of the test substance (Integrated Model for the Differentiation of Skin reactions (IMDS))

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

diethyl N-[3-(trimethoxysilyl)propyl]aspartate

EC Number:

606-274-3

Cas Number:

192389-48-3

Molecular formula:

C14H29NO7Si

IUPAC Name:

diethyl N-[3-(trimethoxysilyl)propyl]aspartate

In vivo test system

Test animals

Species:

mouse

Strain:

NMRI

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Harlan-Winkelmann GmbH, Borchen, Germany
- Age at study initiation: 8-9 weeks
- Weight at study initiation: 27-32 g
- Housing: individual
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: at least 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 2
- Humidity (%): 40 - 70
- Air changes (per hr): about 10
- Photoperiod (hrs dark / hrs light): 12 / 12

Study design: in vivo (LLNA)

Vehicle:

methyl ethyl ketone

Concentration:

0, 3, 10, 30 %

No. of animals per dose:

6

Details on study design:

TREATMENT PREPARATION AND ADMINISTRATION:
The test item in the formulation and the vehicle were applied epicutaneously onto the dorsal part of both ears of the animals. This  treatment was repeated on three consecutive days (d1, d2 and d3). The volume administered was 25µl/ear. The used concentrations were based on the experiences with the test system and the toxic properties of the test substance.
The animals were anaesthetized by inhalation of carbon dioxide and sacrificed one day after the last application (d4). The appropriate organs were then removed. Lymphatic organs (the auricular lymph nodes) were transferred into physiological saline (PBS).
Investigations:
- weight of draining lymph nodes (given as weight index compared to vehicle controls)
- cell counts in draining lymph nodes (given as cell count index compared to vehicle controls)
Stimulation indices were calculated by dividing the absolute weight or number of cell counts of the substance treated lymph nodes by the vehicle treated ones.
- ear swelling (given in 0.01 mm and as index)
- ear weight (given in mg/8 mm diameter punch and as index)
- body weights

Positive control substance(s):

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

Statistics:

When it was statistically reasonable, the values from treated groups were compared with those from the control group by a one-way analysis of variance (ANOVA) when the variances are considered homogeneous according to a homogeneity testing like Cochran's test. Alternatively, if the variances are considered to be heterogenous (p<=0.05), a non-parametric Kruskal-Wallis test has been used (Kruskal-Wallis ANOVA) at significance levels of 5% . Two sided multiple test procedures were done according to Dunnett or Bonferroni-Holm, respectively. Outlying values in the LN weights were eliminated at a probability level of 99% by Nalimov's method. In addition, for the LLNA/IMDS the smallest significant differentes in the means were calculated by Scheffels method, which according to Sachs can be used for both equal and unequal sample sizes.

Results and discussion

Positive control results:

The local lymph node assay with alpha hexyl cinnamic aldehyde shows a clear sensitising potential.

In vivo (LLNA)

Results

Results 1

Key result

Parameter:

SI

Remarks:

Stimulation index: Weight of draining lymph nodes (vehicle control)

Value:

1

Variability:

± 18.09 (mean ± SD in %)

Test group / Remarks:

vehicle control

Results 2

Key result

Parameter:

SI

Remarks:

Stimulation index: Weight of draining lymph nodes (3 % dose)

Value:

0.91

Variability:

± 23.29 (mean ± SD in %)

Test group / Remarks:

3 % dose

Results 3

Key result

Parameter:

SI

Remarks:

Stimulation index: Weight of draining lymph nodes (10 % dose)

Value:

1.14

Variability:

± 16.03 (mean ± SD in %)

Test group / Remarks:

10 % dose

Results 4

Key result

Parameter:

SI

Remarks:

Stimulation index: Weight of draining lymph nodes (30 % dose)

Value:

1.02

Variability:

± 17.18 (mean ± SD in %)

Test group / Remarks:

30 % dose

Results 5

Key result

Parameter:

SI

Remarks:

Stimulation index: Cell count index in draining lymph nodes (vehicle control)

Value:

1

Variability:

± 26.35 (mean ± SD in %)

Test group / Remarks:

vehicle control

Results 6

Key result

Parameter:

SI

Remarks:

Stimulation index: Cell count index in draining lymph nodes (3 % dose)

Value:

1.16

Variability:

± 30.52 (mean ± SD in %)

Test group / Remarks:

3 % dose

Results 7

Key result

Parameter:

SI

Remarks:

Stimulation index: Cell count index in draining lymph nodes (10 % dose)

Value:

1.14

Variability:

± 19.69 (mean ± SD in %)

Test group / Remarks:

10 % dose

Results 8

Key result

Parameter:

SI

Remarks:

Stimulation index: Cell count index in draining lymph nodes (30 % dose)

Value:

1.16

Variability:

± 26.64 (mean ± SD in %)

Test group / Remarks:

30 % dose

Any other information on results incl. tables

Table 1: Summary of the LLNA/IMDS results (means of 6 animals per group)

 

Parameter investigated	Vehicle control	Dose  3 %	Dose   10 %	Dose   30 %
Stimulation index: weight of draining lymph nodes	1.00	0.91	1.14	1.02
Stimulation index: cell count in draining lymph nodes	1.00	1.16	1.14	1.16
Ear swelling in 0.01 mm on day 4 (index)	18.00 (1.00)	18.67 (1.04)	18.00 (1.00)	18.25 (1.01)
Ear weight in mg / 8 mm diameter punch on day 4 (index)	10.80 (1.00)	10.95 (1.01)	10.98 (1.02)	11.24 (1.04)

 

Compared to vehicle treated animals no increase in the stimulation indices for cell counts or for weights of the draining lymph nodes after application of the test item was observed. The "positive level" which is 1.35 for the cell count index was never reached or exceeded in any dose group.

 

The "positive level" of ear swelling which is 2x10-2 mm increase, i.e. about 10% of the control values, has also not been exceeded in any dose group. And no increases of the ear weights could be determined compared to control animals.

 

The body weights of the animals were not affected by any treatment.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information

Executive summary:

KURG 101 was investigated in the modified local lymph node assay (LLNA-IMDS) on female mice according to OECD TG 429. Concentrations of 0 (vehicle control), 3, 10 and 30 % formulated in methyl ethyl ketone were tested. The results show that KURG 101 has neither an irritating nor a sensitising potential in mice after dermal application. Compared to vehicle treated animals none of the parameters measured, i.e. cell counts and weights of the draining lymph nodes, ear weights and ear swelling, reached or exceeded the “positive levels” defined for this assay.