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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
secondary literature
Justification for type of information:
data is from safety assessment reports

Data source

Reference
Reference Type:
secondary source
Title:
Scientific Committee on Consumer Safety - SCCS
Author:
Scientific Committee on Consumer Safety -SCCS
Year:
2010
Bibliographic source:
Scientific Committee on Consumer Safety - SCCS, 2010

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Principles of method if other than guideline:
To assess the skin sensitization potential of the test chemical according to OECD 429 Guidelines
GLP compliance:
not specified
Type of study:
mouse local lymph node assay (LLNA)

Test material

Constituent 1
Chemical structure
Reference substance name:
3-[(4,5-dihydro-3-methyl-5-oxo-1-phenyl-1H-pyrazol-4-yl)azo]-N,N,N-trimethylanilinium chloride
EC Number:
269-943-5
EC Name:
3-[(4,5-dihydro-3-methyl-5-oxo-1-phenyl-1H-pyrazol-4-yl)azo]-N,N,N-trimethylanilinium chloride
Cas Number:
68391-31-1
Molecular formula:
C19H22ClN5O
IUPAC Name:
N,N,N-trimethyl-3-[(3-methyl-5-oxo-1-phenyl-4,5-dihydro-1H-pyrazol-4-yl)diazenyl]anilinium chloride
Test material form:
solid
Details on test material:
Name of test material (as cited in study report):Basic Yellow 57Molecular formula:C19H22N5OClMolecular weight :371.5 (as chloride) Substance type:OrganicPhysical state:SolidPurity: 99.3% (HPLC)Lot/batch No.: 15

In vivo test system

Test animals

Species:
other: Mice
Strain:
other: CBA/CaOlaHsd (nulliparous and non-pregnant)
Sex:
female
Details on test animals and environmental conditions:
No data

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
other: Topical application
Vehicle:
other: ethanol:water, 7:3 (v/v)
Concentration / amount:
2.5%, 5% and 10% (w/v) solutions
Challenge
Concentration / amount:
2.5%, 5% and 10% (w/v) solutions
No. of animals per dose:
Three dose groups of four female mice each, were chosen.
Details on study design:
RANGE FINDING TESTS:In a pre-study evaluation on 2 mice, 1%, 2.5%, 5% and 10% solutions were evaluated.The highest dose (10%) in the main study was considered by the study to be “the highest technically applicable concentration whilst avoiding systemic toxicity and excessive local irritation”. It cannot be excluded that Basic Yellow 57 is a skin sensitizer as the maximum test concentration (10%) is too low.MAIN STUDYA. INDUCTION EXPOSURENo. of exposures: 3Exposure period:3 daysTest groups: 3 test groups consisting of 4 female miceControl group: 1 received only vehicleSite: dorsal area of the ears Frequency of applications: dailyDuration: 3 days Concentrations: The applicationvolume, 25 μl was topically applied to the dorsal surface of ears of test group.OTHER: Five days after the firsttopical application, all mice were administered with radio-labelled thymidine (³HTdR) by intravenous injection via the tail vein.Approximately 5 hours after ³HTdR application all mice were killed. The draining lymph nodes were excised and pooled for each experimental group. After preparation of the lymph nodes, disaggregation and overnight precipitation of macromolecules, these precipitations were re-suspended and transferred to scintillation vials.The level of ³HTdR incorporation was then measured The level of ³HTdR incorporation was then measured by scintillation counting. The proliferative response of lymph node cells is expressed as the ratio of ³HTdR incorporation into lymph node cells of treated animals relative to that recorded in control mice (stimulation index). The proliferative capacity of pooled lymph node cells was determined by quantifying the incorporation of ³H-methyl thymidine
Positive control substance(s):
yes
Remarks:
α-hexylcinnamaldehyde was used as positive control, to show distinct increases in the stimulation index.

Results and discussion

Positive control results:
The positive control used affected an increase in stimulation index with an EC3 of 11.7%.

In vivo (LLNA)

Results
Parameter:
SI
Value:
1.2
Test group / Remarks:
2% Concentration
Remarks on result:
other: not sensitizing
Cellular proliferation data / Observations:
The Stimulation Index (S.I.) was below 3 in all dose groups. No dose response relation was noted.

Any other information on results incl. tables

Table 1: Stimulation Index of test and control groups

 

Concentration

%

Test group

Stimulation Index

2.5

Basic Yellow 57

1.2

5

Basic Yellow 57

1.5

10

Basic Yellow 57

1.5

5

Positive Control

1.5

10

Positive Control

2.3

25

Positive Control

8.4

Applicant's summary and conclusion

Interpretation of results:
other: not sensitizing
Conclusions:
The Stimulation Index (S.I.) was below 3 in all dose groups. No dose response relation was noted. Calculation of the EC 3 value was not performed as the S.I. value did not reach or exceed 3 for any test concentration. The positive control used affected an increase in stimulation index with an EC3 of 11.7%.Based on the criteria of the test system, the test chemical was not a non-sensitizer when tested up to 10% in ethanol:water (7:3 v/v) in mice.
Executive summary:

Mouse Lymph node assay [LLNA] was performed on groups of female mice to assess the skin sensitizing potential of the test chemical.The assay was performed according to OECD 429 Guidelines.

 

Three dose groups and a control group (receiving the vehicle only) of four female mice each, were chosen. Each test group of mice was treated by topical (epidermal) application to the dorsal surface of each ear lobe (left and right) with the different test item concentrations. The application volume, 25 μl, was spread over the entire dorsal surface of each ear lobe once daily for 3consecutive days. The control group was treated with the vehicle. Five days after the first topical application, all mice were administered with radio-labelled thymidine (³HTdR) by intravenous injection via the tail vein.

Approximately 5 hours after ³HTdR application all mice were killed. The draining lymph nodes were excised and pooled for each experimental group. After preparation of the lymph nodes, disaggregation and overnight precipitation of macromolecules, these precipitations were re-suspended and transferred to scintillation vials.

The level of ³HTdR incorporation was then measured by scintillation counting. The proliferative response of lymph node cells is expressed as the ratio of ³HTdR incorporation into lymph node cells of treated animals relative to that recorded in control mice (stimulation index).

α- hexylcinnamaldehyde was used as positive control, to show distinct increases in the stimulation index.

The Stimulation Index (S.I.) was below 3 in all dose groups. No dose response relation was noted. Calculation of the EC 3 value was not performed as the S.I. value did not reach or exceed 3 for any test concentration. The positive control used affected an increase in stimulation index with an EC3 of 11.7%.

Based on the criteria of the test system, the test chemical was not a non-sensitizer when tested up to 10% in ethanol:water (7:3 v/v) in mice.