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

Oral (OECD 423), rat: LD50 = 5000 mg/kg bw (cut-off value, limit test)
Dermal (OECD 404), rat: LD50 > 2000 mg/kg bw (limit test)

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

22 Jul - 08 Aug 2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP - guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.1 tris (Acute Oral Toxicity - Acute Toxic Class Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1100 (Acute Oral Toxicity)

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Test type:

acute toxic class method

Limit test:

yes

Species:

rat

Strain:

other: Wistar Crl:(WI)BR

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland, Sulzfeld, Germany
- Age at study initiation: approximately 11 weeks
- Weight at study initiation: 344 g (mean, males) and 227 g (mean, females)
- Fasting period before study: food was withheld overnight (for a maximum of 20 hours) prior to dosing until 3-4 hours after administration of the test substance
- Housing: group housing of 3 animals per sex per cage in labelled Macrolon cages (type IV; height 18 cm) containing purified sawdust as bedding material (SAWI, Jelu Werk, Rosenberg, Germany)
- Diet: standard pelleted laboratory animal diet (from Altromin (code VRF 1), Lage, Germany), ad libitum
- Water: tap water, ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21.0 ± 3.0 (actual range 17.2-24.5°C)
- Humidity (%):30-70 (actual range: 44-83%)
- Air changes (per hr): approximately 15
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: gavage

Vehicle:

propylene glycol

Details on oral exposure:

VEHICLE
- Amount of vehicle (if gavage): 10 mL/kg bw

MAXIMUM DOSE VOLUME APPLIED: 10 mL/kg bw

CLASS METHOD (if applicable)
- Rationale for the selection of the starting dose: according to OECD 423, if the acute oral toxicity of a substance is expected to be low, a limit test may be performed with the highest dose level of 2000 mg/kg bw

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

Step 1: 3 males
Step 2: 3 females

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: observations of mortality were made twice daily; observations of clinical signs were made several times on Day 1 and daily thereafter, graded according to a severity scale of 1-4; weighing was performed weekly on Day 1 (pre-administration), 8 and 15
- Necropsy of survivors performed: yes, all gross pathological changes were recorded

Sex:

male/female

Dose descriptor:

LD50

Effect level:

5 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: LD50 cut-off point according to OECD 423

Mortality:

There was no mortality during the 14-day study period.

Clinical signs:

other: Uncoordinated movements were noted in all males 2-4 hours after adminstration, lasting until day 2 in 2/3 animals. One male had a hunched posture from 2 hours after dosing until day 3. No clinical signs were observed in the females.

Gross pathology:

Necropsy and histopathological examination revealed no substance-related findings.

Table 1: Mortality and clinical signs

Dose [mg/kg bw]	Toxicological results*	Duration of clinical signs	Time of death	Mortality (%)
Males
2000	0/3/3	1 h - 3 days	-	0
LD50 > 2000 mg/kg bw
Females
2000	0/0/3	-	-	0
LD50 > 2000 mg/kg bw

                                                                                           

* first number = number of dead animals                                 

 second number = number of animals with clinical signs         

 third number = number of animals used                               

Interpretation of results:

not classified

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

Quality of whole database:

The available information comprises an adequate and reliable study (Klimisch score 1), and is thus sufficient to fulfil the standard requirements set out in Annex VII, 8.5, of Regulation (EC) No 1907/2006.

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

21 Jan - 04 Feb 2004

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP-guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.3 (Acute Toxicity (Dermal))

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1200 (Acute Dermal Toxicity)

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

other: Wistar Crl:(Wl) BR

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland, Sulzfeld, Germany
- Age at study initiation: approximately 10 weeks
- Weight at study initiation: 347 ± 18 g (males, mean ± SD), 246 ± 15 g (females, mean ± SD)
- Housing: animals were individually housed in labelled Macrolon cages (type lII, height 15 cm) containing purified sawdust as bedding material (Woody-Clean type 3/4, Tecnilab-BMI B.V., Someren, the Netherlands)
- Diet: standard pelleted laboratory animal diet (Altromin (code VRF 1), Lage, Germany), ad libitum
- Water: tap water, ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18.6-22.9 (actual range)
- Humidity (%): 38-80 (actual range)
- Air changes (per hr): approximately 15
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 21 Jan 2004 To: 04 Feb 2004

Type of coverage:

occlusive

Vehicle:

propylene glycol

Details on dermal exposure:

TEST SITE
- Area of exposure: approximately 25 cm² in males and approximately 18 cm² in females
- % coverage: 10
- Type of wrap if used: the test substace was held in contact with the skin with a surgical gauze patch (Surgy 1 D), which was covered with aluminium foil and Coban elastic bandage. A piece of Micropore tape was used to secure the bandages in females only.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): residual test substance was cleaned from the skin using water
- Time after start of exposure: 24 h

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 10 mL/kg bw
- Constant volume or concentration used: yes
- Concentration (if solution): 200 mg/mL (w/w) (calculated from 10 mL/kg bw amount and 2000 mg/kg bw)


VEHICLE
- Amount(s) applied (volume or weight with unit): 10 mL/kg bw

Duration of exposure:

24 h

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: observations of mortality were made twice daily; observations of clinical signs were made several times on Day 1 and daily thereafter, graded according to a severity scale of 1-4; weighing was performed weekly on Day 1 (pre-administration), 8 and 15
- Necropsy of survivors performed: yes, all gross pathological changes were recorded

Sex:

male/female

Dose descriptor:

LD50

Effect level:

2 000 mg/kg bw

Based on:

test mat.

Mortality:

There was no mortality during the study period.

Clinical signs:

other: Systemic effects were observed on Day 1 from 2 hrs after administration until Day 6. Flat posture was observed in 3/5 males and 3/5 females from 2-4 hrs after dosing, while hunched posture was noted in 4/5 males and 5/5 females, generally with a later ons

Gross pathology:

Ther were no substance-related findings during necropsy and the gross pathological examination.

Other findings:

- Other observations: Mild local effects on the treated skin were seen throughout the study period. Erythema or erythema maculata was observed in 3/5 females on Day 3-5 and 3-4, respectively. Scales and/or scabs were seen in 1/5 males and 4/5 females for a total of 1-10 days between Day 5 and 15.

Table 1: Mortality and clinical signs

Dose [mg/kg bw]	Toxicological results*	Duration of clinical signs	Time of death	Mortality (%)
Males
2000	0/5/5	2 hrs on Day 1 – Day 13	-	0
Females
2000	0/5/5	2 hrs on Day 1 – Day 15	-	0
Overall LD50 > 2000 mg/kg bw

* first number = number of dead animals                                 

 second number = number of animals with systemic clinical signs         

 third number = number of animals used                               

           

Table 2: Overview of clinical signs

Observations	Males (reading time points)					Females (Reading time points)
No.	1	2	3	4	5	1	2	3	4	5
Systemic
Hunched posture	4 hrs, Day 1–Day 2		Day 2-3	Day 2-3	2 hrs, Day 1–Day 2	Day 2-5	4 hrs, Day 1–Day 6	Day 2-4	4 hrs, Day 1–Day 2	Day 2-3
Flat posture		2-4 hrs, Day 1	2-4 hrs, Day 1	2-4 hrs, Day 1				2-4 hrs, Day 1	2 hrs, Day 1	4 hrs, Day 1
Chromodacryorrhoea (snout)	2 hrs, Day 1		2 hrs, Day 1–Day 2				2 hrs, Day 1–Day 2	2 hrs, Day 1–Day 2		2-4 hrs, Day 1
Ptosis			4 hrs, Day 1
Treated skin
Scales				Day 7-13			Day 7-8	Day 5-14	Day 6-8	Day 6-8
Scabs								Day 9, 12-13	Day 15
General erythema (grade 1-4)							Day 3 -5 (grade 1)	Day 3-5 (grade 1)
Erythema maculata (grade 1-4)										Day 3-4 (grade 1)

 

Interpretation of results:

not classified

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

Quality of whole database:

The available information comprises an adequate and reliable study (Klimisch score 1), and is thus sufficient to fulfil the standard requirements set out in Annex VIII, 8.5, of Regulation (EC) No 1907/2006.

Additional information

The acute toxicity 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 assessed in an acute oral and dermal toxicity study.

 

Acute toxicity: oral

In an acute oral toxicity study (performed according to OECD guideline 423), the limit dose of 2000 mg/kg bw UC-141 was administered to male and female rats by gavage (Hooiveld, 2003). No mortality was observed, and there were no effects on body weight during the 14 day observation period. Uncoordinated movements were noted in all males 2 -4 hours after adminstration of the test substance, lasting until day 2 in 2/3 animals. One male had a hunched posture from 2 hours after dosing until day 3. No clinical signs were observed in the females. The necropsy and gross pathological examination did not reveal any treatment-related effects. According to the acute toxic class method described in the OECD guideline 423, if there is no mortality following administration of 2000 mg/kg bw, the LD50 cut-off limit is 5000 mg/kg bw. Therefore, the LD50 is considered to be 5000 mg/kg bw for male and female rats.

Acute toxicity: dermal

The acute dermal toxicity of UC-141 was assessed in a limit test performed according to OECD guideline 402 (Hooiveld, 2004). A single dose of 2000 mg/kg bw of the test substance in propylene glycol was applied to the shaved skin of 5 rats/sex under occlusive conditions for 24 hours. There was no mortality and no effects on body weight were noted during the 14-day observation period. A flat or hunched posture was observed in 4/5 males and 5/5 females up to 6 days after administration. 2/5 males and 3/5 females had chromodacryorrhoea from 2 hours after administration, lasting until Day 2 in 1/5 males and 2/5 females. The necropsy and gross pathological examination did not reveal any treatment-related findings. Mild local effects on the treated skin were seen throughout the study period. Erythema or erythema maculata was observed in 3/5 females on Day 3-5 and 3-4, respectively. Scales and/or scabs were seen in 1/5 males and 4/5 females for in a total of 1-10 days between Day 5 and 15. The LD50 value for systemic toxicity is considered to be > 2000 mg/kg bw.

Justification for selection of acute toxicity – oral endpoint
Only one study is available.

Justification for selection of acute toxicity – inhalation endpoint
The acute inhalation toxicity study is not required as no inhalation exposure is expected.

Justification for selection of acute toxicity – dermal endpoint
Only one study is available.

Justification for classification or non-classification

The available data on the acute oral and dermal toxicity of the test substance does not meet the criteria for classification according to Regulation (EC) 1272/2008 or Directive 67/548/EEC, and is therefore conclusive but not sufficient for classification.