Reaction mass of 5,5'-{(phenylmethanediyl)bis[benzene-4,1-diyl-diazene-2,1-diyl]}bis{1-[3-(dimethylamino)propyl]-4-methyl-6-oxo-3-(pyridinium-1-yl)-1,6-dihydropyridin-2-olate} hydrochloride and 5,5’-[3,4’-(phenylmethanediyl)diphenylene]bis(diazene-2,1-diyl)bis{1-[3-(dimethylamino)propyl]-4-methyl-6-oxo-3-(pyridinium-1-yl)-1,6-dihydropyridin-2-olate} hydrochloride

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

2007-10-02 to 2007-12-18

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline-conform study under GLP without deviations, conducted with the analogue substance.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

analogue substance (refer to IUCLID chapter 13)

IUPAC Name:

analogue substance (refer to IUCLID chapter 13)

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Netherlands BV, Kreuzelweg 53, NL-5961 NM Horst / The Netherlands, Postbus 6174, NL-5960 AD Horst / The Netherlands
- Age at study initiation: 11 weeks (male), 13 weeks (females)
- Weight at study initiation: First Day of Acclimatization: 2027, 2547, 2512 g; Last Day of Observation: 2697, 3377, 3346 g
- Housing: Individually in stainless steel cages equipped with feed hoppers and drinking water bowls.
- Diet (e.g. ad libitum): Pelleted standard rabbit maintenance diet ad libitum
- Water (e.g. ad libitum): Community tap water ad libitum.
- Acclimation period: 14 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 17-23 °C
- Humidity (%): 30-70 %
- Air changes (per hr): 10 - 15
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 2007-10-10 To: 2007-10-29

Test system

Type of coverage:

semiocclusive

Preparation of test site:

other: clipped with an electric clipper

Vehicle:

water

Controls:

not required

Amount / concentration applied:

500 mg

Duration of treatment / exposure:

4 h

Observation period:

14 days

Number of animals:

3

Details on study design:

TEST SITE
- Area of exposure: left flank
- % coverage:
- Type of wrap if used: test item was placed on a surgical gauze patch (ca. 2.5 cm x 2.5 cm). This gauze patch was applied to the intact skin of the clipped area. The patch was covered with a semi-occlusive dressing. The dressing was wrapped around the abdomen and anchored with tape.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): after remocval of dressing the skin was flushed with lukewarm tap water
- Time after start of exposure: 4 hours

SCORING SYSTEM: The skin reaction was assessed according to the numerical scoring system listed in the Commission Directive 2004/73/EC, April 29, 2004.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Remarks:

average of animals 1, 2, and 3

Time point:

other: overall at 1, 24, and 48 h

Score:

0.33

Max. score:

4

Reversibility:

fully reversible within: 7 d

Results 2

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

other: 72 h

Score:

1

Max. score:

4

Reversibility:

fully reversible within: 7 days

Results 3

Irritation parameter:

erythema score

Basis:

animal: 1 and 2

Time point:

other: 72 h

Score:

0

Max. score:

4

Results 4

Irritation parameter:

edema score

Basis:

other: mean score for all three animals

Time point:

other: overall at 1, 24, 48 and 72 h

Score:

0

Max. score:

4

Irritant / corrosive response data:

Reversibility of any observed effect: Changes fully reversible within 7 days at latest

Other effects:

VIABILITY/MORTALITY/CLINICAL SIGNS: No clinical signs of systemic toxicity were observed in the animals during the study and no mortality occurred.
IRRITATION: The skin assessment of all animals was prevented by a marked yellow staining produced by the test item 1-48 hours after treatment and persisted as slight staining up to day 14. When assessable at the 72-hour observation a very slight erythema was noted in one female, only. No oedema was present in all animals during the whole observation period.
COLORATION: A marked yellow staining produced by the test item was recorded in all animals at the 1-hour observation and persisted as slight staining up to day 14.
CORROSION:
Neither alterations of the treated skin were observed nor were corrosive effects evident on the skin.
BODY WEIGHTS: The body weights of all rabbits were considered to be within the normal range of variability.

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Erythema score could not be investigated in detail, as substance left a yellow staining on the treated skin. However based on the available data the substance still can be considered "not irritating". Criteria used for interpretation of results: OECD GHS

Conclusions:

Based on the classification criteria according to CLP and DSD, the analogue substance is considered to be “not irritating” to rabbit skin regarding the oedema and erythema. Non-classification is likely to apply to the substance registered as well.

Executive summary:

The primary skin irritation potential of the analogue substance was being investigated following the testing protocol as given in OECD guideline 404.

The analogue substance was applied by topical semi-occlusive application of 0.5 g to the intact left flank of each of three young adult New Zealand White rabbits. The duration of treatment was four hours. The scoring of skin reactions was performed 1, 24, 48 and 72 hours, as well as 7, 10 and 14 days after removal of the dressing.

The skin assessment of all animals was prevented by a marked yellow staining produced by the test item 1-48 hours after treatment and persisted as slight staining up to day 14. When assessable at the 72-hour observation a very slight erythema was noted in one female, only. No oedema was present in all animals during the whole observation period.

The mean score is usually calculated across 3 scoring times (24, 48 and 72 hours after patch removal) for each animal for erythema/eschar grades and for oedema grades, separately.

The skin assessment of all animals was prevented 1-48 hours after treatment by a yellow staining produced by the test item. Therefore, the mean score was not calculated.

No corrosive effects were noted on the treated skin of any animal at any of the measuring intervals and no clinical signs were observed.

Thus, the test item did not induce significant or irreversible damage to the skin.

Based upon the referred classification criteria (Commission Directive 2001/59/EC of August 2001), the analogue substance is considered to be “not irritating” to rabbit skin regarding the oedema. Although the erythema assessment was not possible from the 1- to 48-hour observations due to a yellow staining, the test item is assumed to be “not irritating” for the erythema, as well.

Given the applicability of the proposed read across approach (see IUCLID chapter 13) non-classification is likely to apply to the substance registered as well.