2-amino-2',5-dichlorobenzophenone

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

01 Sep - 12 Dec 2005

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2005

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

The present study pre-dates the requirement for the murine local lymph node assay (LLNA) as the first-choice method for in vivo testing, and thus fulfils the standard information requirements in accordance with Annex VII, Section 8.3 of Regulation (EC) No. 1907/2006.

Test material

Test material information

Constituent 1

Reference substance name:

2-amino-2',5-dichlorobenzophenone

EC Number:

220-985-2

EC Name:

2-amino-2',5-dichlorobenzophenone

Cas Number:

2958-36-3

Molecular formula:

C13H9Cl2NO

IUPAC Name:

4-chloro-2-(2-chlorobenzoyl)aniline

Test material form:

solid: particulate/powder

In vivo test system

Test animals

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

male

Details on test animals and environmental conditions:

TEST ANIMALS
- Age at study initiation: 18 days
- Weight at study initiation: males 323.9 g ± 10.5 g
- Housing: 5 animals/cage
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 14 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19.5- 20.5 °C
- Humidity (%): 30 - 65 %
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal

Vehicle:

other: 0.5% (w/v) solution of Tylose MH 1000 ("TS") in deionised water

Concentration / amount:

5%

Day(s)/duration:

Day 0 of study

Adequacy of induction:

highest concentration used causing mild-to-moderate skin irritation and well-tolerated systemically

Induction 2

Route:

epicutaneous, occlusive

Vehicle:

petrolatum

Remarks:

(Vaseline)

Concentration / amount:

25%

Day(s)/duration:

Day 7 of study

Adequacy of induction:

highest technically applicable concentration used

Challenge

Route:

epicutaneous, occlusive

Vehicle:

petrolatum

Remarks:

(Vaseline)

Concentration / amount:

25%

Day(s)/duration:

Day 21 of study

Adequacy of challenge:

other: highest technically applicable concentration used

No. of animals per dose:

Control group: 5
Test group: 15

Details on study design:

Pilot Study:
The aim of the pilot study was to find out the highest concentrations which cause mild-tomoderate skin irritation after intracutaneous and epicutaneous
administration and the highest non-irritant concentration after epicutaneous administration.

Main study:
Three pairs of intracutaneous injections of 0.1 ml volume were given to each animal in the shoulder region so that one of each pair lies on each side of the
midline in cranial to caudal sequence.
Dose group:
Injection 1: mixture of Aqua pro injectione and FCA (1:1, v/v)
Injection 2: 5 % (w/v) suspension ofthe test item in TS
Injection 3: 5% (w/v) suspension ofthe test item in FCA/ Aqua pro injectione (1 :1, v/v)

Control group:
Injection 1: mixture of Aqua pro injectione and FCA (1: 1, v/v)
Injection 2: TS
Injection 3: 50 % mixture (w/v) of TS in a mixture of Aqua pro injectione and FCA (1: 1, v/v)

Day 7: lnduction by Epicutaneous Administration
Dose group:
One layer of filter paper (2 x 4 cm) was loaded with 0.5 g of the 25 % (w/w) mixture of the test item with vaseline. One patch each was then placed on the skin ofboth sides ofthe body.
Control group:
One layer of filter paper (2 x 4 cm) was loaded with 0.5 g of vaseline. One patch each was then placed on the skin ofboth sides ofthe body.

Day 21: Challenge by Epicutaneous Administration:
Dose and control group:
One strip of gauze patch was loaded with 0.5 g of the 25 % (w/w) mixture of the test item with vaseline and applied to the right flank of all animals.
Other strips of gauze patch were loaded with 0.5 g of vaseline and applied to the left flank of all animals.
All patches were covered with film and held in contact with the skin by occlusive dressing. After 24 hours the patches were removed and the administration areas were cleaned with corn oil.

Days 23 and 24: Assessment of Challenge Reaction
At 24 and 48 hours after patch removal ( 48 and 72 hours after start of challenge) the skin reaction was observed and recorded according to the
MAGNUSSON and KLIGMAN grading
scale

Positive control substance(s):

yes

Remarks:

The sensitivity of the strain of guinea pig (Dunkin Hartley, Crl:(HA)BR) and reliability of the experimental technique used is checked routinely by use of the known mild skin sensitiser Benzocaine.

Results and discussion

Positive control results:

Not included in this test. However, strain sensitivity is checked periodically with known sensitizers.

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

0.5 and 25% (induction), 25% (challenge)

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

no indication of skin sensitisation

Results 2

Reading:

2nd reading

Hours after challenge:

72

Group:

test chemical

Dose level:

0.5 and 25% (induction), 25% (challenge)

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

no indication of skin sensitisation

Results 3

Reading:

1st reading

Hours after challenge:

48

Group:

negative control

No. with + reactions:

0

Total no. in group:

5

Remarks on result:

no indication of skin sensitisation

Results 4

Reading:

2nd reading

Hours after challenge:

72

Group:

negative control

No. with + reactions:

0

Total no. in group:

5

Remarks on result:

no indication of skin sensitisation

Any other information on results incl. tables

Any other information on materials and methods incl. tables

Animal supplier: Charles River Wiga GmbH, D-97320 Sulzfeld

 

Draize score

Erythema and eschar formation	Score
No erythema	0
Very slight erythema (barely preceptible)	1
Well defined erythema	2
Moderate to severe erythema	3
Severe erythema (beet redness) to slight eschar formation (injuries in depth)	4
Edema formation	Score
No edema	0
Very slight edema (barely preceptible)	1
Slight edema (edges of area well defined by definite raising)	2
Moderate edema (raised approximately 1 mm)	3
Severe edema (raised more than 1 mm and extending beyond area of exposure)	4

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

In accordance with the results of this study and in accordance with the criteria of Regulation /EC) 1272/2008, ADB is not a skin sensitiser.