2-(4-tert-butylphenyl)-6-cyano-5-[bis(ethoxycarbonylmethyl)carbamoyloxy]-1H-pyrrolo[1,2-b][1,2,4] triazole-7-carboxylic acid 2,6-di-tert-butyl-4-methylcyclohexylester

Endpoint summary

Description of key information

Skin irritation (OECD 404): not irritating
Eye irritation (OECD 405): not irritating

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

20 - 29 Aug 2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP - guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2500 (Acute Dermal Irritation)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Japanese Ministry of Agriculture, Forestry and Fisheries (JMAFF), 12 Nousan, Notification No. 8147, November 2000, inciuding the most recent partial revisions

Deviations:

no

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland, Kisslegg, Germany
- Age at study initiation: 8-10 weeks
- Weight at study initiation: 1720-2147 g
- Housing: individually in labelled cages with perforated floors (Scanbur, Denmark, dimensions 56x44x37.5 cm)
- Diet: approximately 100 g/d standard laboratory rabbit diet (Charles River Breeding and Maintenance Diet for Rabbits, Altromin, Lage, Germany). In addition, pressed hay (BMI, Helmond, the Netherlands) was provided twice a week.
- Water: tap water, ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21.0 ± 3.0 (actual range: 17.4-21.7 °C)
- Humidity (%): 30-70 (actual range: 43-89%)
- Air changes (per hr): approximately 15
- Photoperiod (hrs dark / hrs light): 12/12

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

other: The powdery test substance was moistened with water (Milli-U) immediately before application

Controls:

other: the untreated, shaved skin served as the control

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 g. The test substance was moistened with 1 mL of water prior to application.

Duration of treatment / exposure:

4 h

Observation period:

72 h
The skin reactions were assessed at approximately 1, 24, 48 and 72 hours after the removal of the test substance

Number of animals:

3 males

Details on study design:

TEST SITE
- Area of exposure: approximately 2 x 3 cm
- Type of wrap if used: the test substance was applied on a metalline patch (2 x 3 cm), which was mounted on Micropore tape, wrapped around the abdomen, and secured with Coban elastic bandage

REMOVAL OF TEST SUBSTANCE
- Washing (if done): the skin was cleaned with water
- Time after start of exposure: 4 h

SCORING SYSTEM: Draize scoring system

Irritation parameter:

erythema score

Basis:

mean

Remarks:

of all 3 animals

Time point:

other: mean of 24, 48 and 72 h

Score:

0

Max. score:

4

Reversibility:

other: reversibility not applicable

Irritation parameter:

edema score

Basis:

mean

Remarks:

of all 3 animals

Time point:

other: mean of 24, 48 and 72 h

Score:

0

Max. score:

4

Reversibility:

other: reversibility not applicable

Irritant / corrosive response data:

No signs of skin irritation were observed in any of the 3 animals. All the scores were 0 at all reading time points.

Other effects:

There was no mortality, no signs of toxicity and no effects on body weight during the study period. No staining of the treated skin by the test substance was observed.

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

CLP: not classified
DSD: not classified

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

25 Aug - 04 Sep 2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP - guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.5 (Acute Toxicity: Eye Irritation / Corrosion)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2400 (Acute Eye Irritation)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Japanese Ministry of Agriculture, Forestry and Fisheries (JMAFF), 12 Nousan, Notification No. 8147, November 2000, inciuding the most recent partial revisions

Deviations:

no

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland, Kisslegg, Germany
- Age at study initiation: 7-9 weeks
- Weight at study initiation: 1686-2017 g
- Housing: individually in labelled cages with perforated floors (Scanbur, Denmark, dimensions 56x44x37.5 cm)
- Diet: approximately 100 g/d standard laboratory rabbit diet (Charles River Breeding and Maintenance Diet for Rabbits, Altromin, Lage, Germany). In addition, pressed hay (BMI, Helmond, the Netherlands) was provided twice a week.
- Water: tap water, ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21.0 ± 3.0 (actual range: 18.0-23.2 °C)
- Humidity (%): 30-70 (actual range: 39-79%)
- Air changes (per hr): approximately 15
- Photoperiod (hrs dark / hrs light): 12/12

Vehicle:

unchanged (no vehicle)

Controls:

other: the untreated eye served as the control

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit):49.3 mg (range: 48.8 — 49.7 mg), a volume of approximately 0.1 mL

Duration of treatment / exposure:

Single application without washing

Observation period (in vivo):

72 h
Reading time points: approximately 1, 24, 48 and 72 hours

Number of animals or in vitro replicates:

3 males

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing (if done): the eye remained unwashed

SCORING SYSTEM: Draize scoring system

TOOL USED TO ASSESS SCORE: Fluorescein. Immediately after the 24-hour observation, a solution of 2% fluorescein in water (adjusted to pH 7.0) was instilled into both eyes of each animal to quantitatively determine corneal epithelial damage. Where standard lighting was considered inadequate for observing minor effects, eye examinations were performed using an ophthalmic examination lamp.

Irritation parameter:

cornea opacity score

Basis:

mean

Remarks:

of all 3 animals

Time point:

other: mean of 24, 48 and 72 h

Score:

0

Max. score:

4

Reversibility:

other: reversibility not applicable

Irritation parameter:

iris score

Basis:

mean

Remarks:

of all 3 animals

Time point:

other: mean of 24, 48 and 72 h

Score:

0

Max. score:

4

Reversibility:

other: reversibility not applicable

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

other: mean of 24, 48 and 72 h

Score:

0.67

Max. score:

3

Reversibility:

fully reversible within: 72 h

Irritation parameter:

conjunctivae score

Basis:

animal #2

Time point:

other: mean of 24, 48 and 72 h

Score:

0

Max. score:

3

Reversibility:

other: reversibility not applicable

Irritation parameter:

conjunctivae score

Basis:

animal #3

Time point:

other: mean of 24, 48 and 72 h

Score:

0.33

Max. score:

3

Reversibility:

fully reversible within: 48 h

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

other: mean of 24, 48 and 72 h

Score:

0.33

Max. score:

4

Reversibility:

fully reversible within: 48 h

Irritation parameter:

chemosis score

Basis:

animal #2

Time point:

other: mean of 24, 48 and 72 h

Score:

0.33

Max. score:

4

Reversibility:

fully reversible within: 48 h

Irritation parameter:

chemosis score

Basis:

animal #3

Time point:

other: mean of 24, 48 and 72 h

Score:

0

Max. score:

4

Reversibility:

other: reversibility not applicable

Irritant / corrosive response data:

Remnants of the test substance were observed in the treated eye of 3/3 animals on day 1. lridial irritation grade 1 was observed in 1/3 animals at the 1-hour reading time point, but had cleared completely within 24 hours. 1 hour after instillation, the conjunctival irritation consisted of mild-moderate redness and chemosis in 3/3 rabbits. The severity was reduced in all rabbits within 24 hours, with 1/3 animals free of conjunctivae and 1/3 free of chemosis. All effects were completely reversible within 48 hours for two animals and within 72 hours for the third animal. A slight dulling of the normal lustre of the cornea was noted in 1/3 animals. The corneal injury had resolved within 24 hours.

Other effects:

There was no mortality, and no signs of systemic toxicity were observed. The body weight was not affected by the treatment.

Table 1: individual eye irritation scores 

Rabbit #	Time [h]	conjunctivae		iris	cornea		conjunctivae		iris	cornea
		redness	swelling				redness	swelling
1	1	2	2	1	1
	24	1	1	0	0
	48	1	0	0	0
	72	0	0	0	0
	average	0.67	0.33	0.0	0.0	Time to reversion	72.0	48.0	0.0	24.0
2	1	1	2	0	0
	24	0	1	0	0
	48	0	0	0	0
	72	0	0	0	0
	average	0.0	0.33	0.0	0.0	Time to reversion	24.0	48.0	0.0	0.0
3	1	1	1	0	0
	24	1	0	0	0
	48	0	0	0	0
	72	0	0	0	0
	average	0.33	0.0	0.0	0.0	Time to reversion	48.0	24.0	0.0	0.0

	Time [h]	conjunctivae		iris	cornea
		redness	swelling			avg. time to reversion	48.0	40.0	0.0	8.0
average score	1	1.33	1.67	0.00	0.33
	24	0.67	0.67	0.00	0.00
	48	0.33	0.00	0.00	0.00
	72	0.00	0.00	0.00	0.00
	24+48+72	0.78	0.78	0.00	0.00

 

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

CLP: not classified
DSD: not classified

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

A study assessing the skin irritation potential of 2-(4-tert-butylphenyl)-6-cyano-5-[bis(ethoxycarbonylmethyl)carbamoyloxy]-1 H-pyrrolo[1 ,2-b][1 ,2,4]triazole-7-carboxylic acid-2,6-di-tert-butyl-4-methyl-cyclohexyl ester (UC-141) was performed according to OECD guideline 404 with 6 rabbits (Hooiveld, 2003). 0.5 g of the test substance was moistened with 1.0 mL of water and applied to the shaved skin of the rabbits under semiocclusive conditions for 4 hours. There were no skin irritation effects observed in any of the animals at the reference time points 1, 24, 48 and 72 h. The scores for erythema and edema were 0 at all reference time points. There was no mortality and no signs of systemic toxicity were observed.

To evaluate the eye irritation potential of UC-141, a study was performed according to OECD guideline 405 (Hooiveld, 2003). 49.3 mg (approximately 0.1 mL) was instilled into one eye of 3 male rabbits. The eyes were not washed after instillation. The irritating effect was assessed 1, 24, 48 and 72 hours after the treatment. The mean value of the conjunctivae score of 24, 48 and 72 -hour reading time points was 0.67, 0 and 0.33, respectively, for animal No. 1, 2 and 3. The chemosis score, given as the mean value of reading time point 24, 48 and 72 hours, was 0.33, 0.33 and 0 for animal No. 1, 2 and 3, respectively. The conjunctivae was completely reversible within 72 hours, while the chemosis had cleared within 48 hours. The minimal irritation effects observed in the eye are not sufficient to classify the test substance for eye irritation.

Justification for selection of skin irritation / corrosion endpoint:
Only one study is available.

Justification for selection of eye irritation endpoint:
Only one study is available.

Justification for classification or non-classification

The available data on skin irritation and on eye irritation of the test substance do not meet the criteria for classification according to Regulation (EC) 1272/2008 or Directive 67/548/EEC, and are therefore conclusive but not sufficient for classification.