[No public or meaningful name is available]

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Remarks:

in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

Measurement of cell proliferation was made by cell counting instead of radioactive labeling and the acute inflammatory skin reaction is determined to discriminate specific from non-specific activation of immune competent cells in the draining lymph nodes.

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: EC Guideline 2004/73/EC (29th Adaptation of Guideline 67/548/EEC, B.42)/Health Effects Test Guideline and OPPTS 870.2600(EPA)

Principles of method if other than guideline:

A modified Local Lymph Node Assay (IMDS) was performed on 24 female NMRI mice of the strain Hsd Win:NMRI (6 animals/test item group and 6 control animals) to determine if there is any specific (sensitising) or non-specific (irritant) stimulating potential of the test item Disflamoll DPK.

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

Diphenyl tolyl phosphate

EC Number:

247-693-8

EC Name:

Diphenyl tolyl phosphate

Cas Number:

26444-49-5

Molecular formula:

C19H17O4P

IUPAC Name:

methylphenyl diphenyl phosphate

Details on test material:

Disflamoll DPK, Batch No.: CH3/22010; CAS No.: 26444-49-5; Chemical name (CAS) Phosphoric acid, methylphenyl diphenyl ester; Content: not given by the sponsor; Approval: until January 22. 2012; Sum formular: C19H17O4P; Molar mass 340.3 g/mol; Physical state: liquid; Appearance: colourless, clear; Storage: room temperature.

In vivo test system

Test animals

Species:

mouse

Strain:

NMRI

Sex:

female

Details on test animals and environmental conditions:

Animals
Selection of the species
SPF-bred female NMRl mice of the strain Hsd Win:NMRI were used from commercial breeder. Historical data on their physiology and spontaneous alterations are available.

Age and Bod weight
The mice exhibited a weight of 26 - 33 grams at the beginning of the study. The age of the animals was 7 weeks.

Housing of the animals
Housing conditions
During the adaptation period up to 8 mice were housed together in conventional Makrolon type III cages,while during the study period the animals were single-housed in type II cages.
Low-dust wood shavings were used as bedding.

Environmental conditions
The environmental conditions in the animal room were standardized as follows:
Room temperature: 22±2°C
Relative humidity: 40%-70%
Light/dark cycle: 12 h/12 h, with artificial illumination
Air throughput: About 10 changes per hour

Study design: in vivo (LLNA)

Vehicle:

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

Concentration:

0 (vehicle control), 2%, 10% and 50%.

No. of animals per dose:

6

Results and discussion

In vivo (LLNA)

Results

Results 1

Key result

Parameter:

SI

Value:

1

Test group / Remarks:

0 (control)

Results 2

Key result

Parameter:

SI

Value:

1.16

Test group / Remarks:

Dose 2%

Results 3

Key result

Parameter:

SI

Value:

1.24

Test group / Remarks:

Dose 10%

Results 4

Key result

Parameter:

SI

Value:

1.1

Test group / Remarks:

Dose 50%

Any other information on results incl. tables

1. Direct LLNA (NMRI mice, female, 6 animal/group)

Dose (%)	Weight index	Cell count index
	(index of mean +/- SD in %)
0*	1.00 +/- 11.18	1.00 +/- 25.05
2	1.16 +/- 21.67	1.16 +/- 21.02
10	1.18 +/- 28.28	1.24 +/- 31.22
50	1.01 +/- 24.65	1.10 +/- 36.81

2. Ear swelling (NMRI mice, female, 6 animals/group, in 0.01 mm)

Dose (%)	day 1	day 4	Index day 4
	(mean +/- SD in %)
0*	17.50 +/- 2.98	17.83 +/- 4.02	1.00
2	17.75 +/- 2.55	18.08 +/- 2.85	1.01
10	17.67 +/- 3.69	18.42 +/- 4.89	1.03
50	17.17 +/- 4.18	17.67 +/- 4.41	0.99

3. Ear weight (NMRI mice, female, 6 animals/group, in mg per 8 mm diameter punch)

Dose (%)	day 4 (mean +/- SD in %)	Index day 4
0*	12.01 +/- 4.87	1.00
2	12.05 +/- 4.58	1.00
10	11.99 +/- 9.03	1.00
50	11.65 +/- 7.40	0.97

*= AOO (Acetone/ olive oil)

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Compared to vehicle-treated animals, none of the parameters measured in the substance-treated groups, 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. These results show that there is no indication for a skin senzitizing effect after administration of a concentration of up to and including 50% Disflamoll DPK in the test system.

Executive summary:

A modified Local Lymph Node assay (IMDS) was performed in 2010 on 24 female NMRI mice of the strain HsD Win:NMRI (6 animals/test item group and 6 control animals to determine if there is any specific (sensitizing) or non-specific (irritant) stimulating potential of the test item Disflamoll DPK.

The study was conducted according OECD Guidelines No. 429 and No. 406, EC Guideline 2004/73/EC (29th Adaption of Guideline 67/548/EEC, B.42)/Health Effects test Guideline and OPPTS 870.2600 (EPA) with the following test item concentrations:

0 (vehicle control), 2%, 10% and 50%.

The modification of the assay by measuring the cell counts instead of radioactive labeling provides comparable sensitivity , and has the advantage that the cell suspension can be further analyzed by different methods (flow cytometry, chemiluminescence responses, immunofluorescence) to gain an insight into mechanistic events. A further modification was done by including the measurement of the ear swelling after treatment leading to a much simplified and reliable assay (Integral Model for the Differentiation of Skin reactions (IMDS). By comparing the specific immune reaction induced by the test item in the draining lymph nodes (LN; cell counts /LN weights) with the immediate unspecific acute skin reaction (ear swelling/ear weight) it is possible to discriminate the irritant potential from the sensitizing potential of the compound tested. International standards have been successfully determined using this modification. Such modifications are also authorized in the Note of Guidance SWP/2145/00 of the CPMP (2001) and OECD guideline 429. With respect to this simple discrimination between sensitizing and irritant local reactions comparable findings have been reported in the human patch test system.

The test item was formulated in acetone/olive oil (4:1) to yield a solution.

Compared to vehicle-treated animals, none of the parameters measured in the substance-treated groups, 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. These results show that there is no indication for a skin senzitizing effect after administration of a concentration of up to and including 50% Disflamoll DPK in the test system.

In conclusion, these results show that the test item Disflamoll DPK has no sensitizing potential in mice after dermal application of up to and including a 50% concentration. No indication for a non-specific (irritant) activation was detected, either. Therefore, the concentration of 50% turned out to be the NOEL for the parameters investigated in this study with respect to skin sensitization.