2-amino-6-methyl-4-propyl-1,2,4-triazolo[1,5-a]pyrimidin-5(4H)-one

Endpoint summary

Description of key information

Oral: Discriminating dose = 100 mg/kg bw, male, Macaca fascicularis, pre-guideline study, Purser 1978

Dermal: Discriminating dose = 2000 mg/kg bw, male/female, rat, pre-guideline study, Davison 1988

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Reference 1

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

Three beagle dogs were dosed with 3 mg/kg test substance by oral gavage. The dogs were pre-treated differently to provide differing stomach conditions for dosage of the test substance to investigate the effect of stomach status on emesis.

GLP compliance:

no

Test type:

standard acute method

Limit test:

yes

Species:

dog

Strain:

other: Beagle

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: approximately 6 months
- Fasting period before study: food 24 hours and water 1.5 hours
- Housing: CTL Dog House
- Diet: 350 g daily LABORATORY DIET A
- Water: ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 21

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

The dogs were pre-treated differently to provide differing stomach conditions for dosage of the test substance:
- Male 1: Fed, 350 g laboratory diet A, 30 minutes pre-dose.
- Female 2: Dosed 50 mL COMPLAN solution (6 g in 50 mL water) by gavage immediately pre-dose.
- Female 4: None, dosed on an empty stomach.

Doses:

0.5 mL/kg to give a dose level of 3 mg/kg

No. of animals per sex per dose:

1 animal per treatment

Control animals:

no

Details on study design:

The dogs were observed continuously for 1 hour after dosing and then regularly for the remainder of the working day. At the end of the day food and water was provided and the dogs returned to stock.

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 3 mg/kg bw

Based on:

act. ingr.

Remarks on result:

other: The substance causes emesis therefore it is unlikely that the complete dose will be available for uptake.

Mortality:

No mortality observed

Clinical signs:

other: Male 1: Four minute after dosing licking of lips, indicating nausea, was apparent and 2 minutes later a small quantity of food was vomited and immediately reingested. Another quantity of food was vomited 12 minutes after dosing and again reingested. Visci

Interpretation of results:

not classified

Conclusions:

3 mg/kg test substance causes emesis in dogs regardless of the stomach state. No mortallity was observed.

Executive summary:

Three beagles were dosed with 3 mg/kg test substance by oral gavage. The dogs were pre-treated differently to provide differing stomach conditions for dosage of the test substance to investigate the effect of stomach status on emesis. One dog was fed 350 g laboratory diet A, 30 minutes pre-dose. Another dog was fed 50 mL COMPLAN solution (6 g in 50 mL water) by gavage immediately pre-dose. The last dog was dosed on an empty stomach. The dogs were observed continuously for 1 hour after dosing and then regularly for the remainder of the working day. No mortality was observed. The test substance caused emesis in all dogs regardless of the stomach state. The effect was most severe when dosed on an empty stomach.

Reference 2

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

One beagle dog per sex/dose was dosed with 0, 0.1, 0.5, 1.0, 3.0, 10.0, or 20.0 mg/kg test substance by oral gavage and observed for 7 days.

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Species:

dog

Strain:

other: Beagle

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: Approximately 5 months
- Weight at study initiation: mean weight males is 12.0 kg and females 10.6 kg
- Fasting period before study: 24 hours
- Housing: individually, CTL doghouse
- Diet: 350 g LABORATORY DIET A, daily
- Water: ad libitum
- Acclimation period: 6 - 7 weeks

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 - 22

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

DOSAGE PREPARATION:
The paste and aqueous solutions were prepared correcting for purity. The concentration of the test substance in solution was 0.02, 0.1, 0.2, 0.6, 1.0, and 1.0 % with a dose volume of 0.5, 0.5, 0.5, 0.5, 1.0, and 2.0 mL/kg and resulted in a dose level of 0.1, 0.5, 1.0, 3.0, 10.0, and 20.0 mg/kg, respectively.

Doses:

0.1, 0.5, 1.0, 3.0, 10.0, and 20.0 mg/kg

No. of animals per sex per dose:

1

Control animals:

yes

Remarks:

No treatment

Details on study design:

- Pre-treatment: On the day of dosing (day 1), each dog received 6 g of COMPLAN as 50 mL aqueous suspension, by gavage approximately 24 hrs after the last normal feed.
- Treatment: Immediately after pre-treatment, the test solution was administered via the tube followed by 10 mL water. Food and water were then withheld until 5 - 6 hours after dosing.
- Duration of observation period following administration: 7 days. At the end of the 7 day observation period, all dogs were returned to stock.


- Clinical Investigations: Each dog was given a detailed clinical examination, including cardiac and pulmonary auscultation, prestudy and then on days 1 and 7. Clinical observations were made 2 or 3 times daily; on the day of dosing , each dog was observed continuously for the immediate 2 hour post -dose period and then regularly during the remainder of the day. Faecal consistency was recorded twice daily during the 7 day observation period.
- Body weights: Each dog was weighed, prior to feeding, on day -1, day 3 and day 7. The weights recorded on day -1 were used to calculate dosage.
- Food Consumption: 24 hour food residues were measured daily during the 7 day observation period, just prior to feeding.

Sex:

male/female

Dose descriptor:

discriminating dose

Effect level:

20 mg/kg bw

Based on:

act. ingr.

Remarks on result:

other: The substance causes emesis therefore it is unlikely that the complete dose will be available for uptake.

Mortality:

No mortality observed.

Clinical signs:

other: EMESIS - No effects were seen at dose levels of 0 or 0.1 mg/kg. Dose levels of 0.5, 1.0, 3.0, 10.0 and 20.0 mg/kg caused emesis in a dose-related manner in terms of onset, duration and severity. - Dose levels of 0.5 and 1.0 mg/kg produced emesis within 1

Other findings:

Food consumption was 100% at all times in all dogs.

Interpretation of results:

not classified

Conclusions:

No mortality was observed up to a dose of 20 mg/kg.

Executive summary:

One beagle per sex/dose was dosed with 0, 0.1, 0.5, 1.0, 3.0, 10.0, or 20.0 mg/kg test substance (corrected for impurity) by oral gavage and observed for 7 days. No mortality occurred. When dosed orally to dogs, the test substance caused emesis at dose levels in the range of 0.5 mg/kg to 20 mg/kg. The onset of vomiting was dose related being slowest at 0.5 mg/kg (25-27 minutes after dosing) and most rapid at 10 and 20 mg/kg (5 minutes in each case). The severity of effects was also dose-related and severe vomiting was seen at dose levels of 3 mg/kg and above. The female dog dosed with 20 mg/kg was more severely affected than any other dog and did not fully recover until 6 hrs after dosing. Apart from the immediate effects of the test substance on the gastrointestinal tract there were no other adverse effects of treatment.

Reference 3

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

Ten male Macaca fascicularis were exposed to a single dose of 100 mg/kg bw test substance via oral gavage followed by a 14-day observation period.

GLP compliance:

no

Test type:

standard acute method

Limit test:

yes

Species:

monkey

Strain:

other: Macaca fascicularis

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: between 2.3 and 4.4 kg
- Fasting period before study: at least 16 hours
- Housing: 70 cm x 68 cm x 98 cm aluminium and stainless steel cages.
- Diet: 200 g dry diet consisting of a 1:1 ratio of F.P.I and Mazuri Primate Diet, 2 x 25 g Bonio biscuits, a daily slice of brown bread and on 5 out of 7 days a weighed quantity of fresh fruit of vegetable produce.
- Water: tap water, ad libitum. Blackcurrant Syrup B.P.C. and Cytacon vitamin B12 liquid, 20 mL of each, was added to a litre of tap water.
- Acclimation period: at least 2 weeks

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3
- Air changes: well-ventilated holding area

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

MAXIMUM DOSE VOLUME APPLIED:
All doses were made up to a total volume of 100 mL with tap water.

DOSAGE PREPARATION:
Aqueous dosing solutions containing 5 mg test substance were freshly prepared shortly before use.

Doses:

100 mg/kg

No. of animals per sex per dose:

10

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Examinations performed: clinical signs including vomiting behaviour (continuously for the first 6 hours after dosing and then twice daily), body weight (weekly), food consumption (daily), post mortem examination of one animal.

Preliminary study:

A previous study was performed in cynomolgus monkeys with doses up to 30 mg/kg. All animals in this study made a full recovery.

Sex:

male

Dose descriptor:

LD50

Effect level:

> 100 mg/kg bw

Based on:

test mat.

Remarks on result:

other: The substance causes emesis therefore it is unlikely that the complete dose will be available for uptake.

Mortality:

4 out of 10 animals died within 24 hours after dosing.

Clinical signs:

other: VOMITING BEHAVIOUR One animal failed to vomit, although increased salvation was observed 30 minutes after dosing. All others animals first vomited between 4 and 43 minutes after dosing. In all but 3 animals, vomiting was observed only during the first hou

Gross pathology:

Post mortem examination was performed in one animal (which failed to vomit). This animal suffered dyspnoea prior to death. Copious amounts of grey/green fluid emanated from the trachea when cut. The lungs appeared to be slightly oedematous and on compression more grey/green fluid exuded from the trachea. The stomach was found to be filled with a similar grey/green fluid. The oesophagus was not ruptured. The indication was that this animal had inhaled vomit.

Other findings:

FOOD CONSUMPTION
Treatment had no effect on food consumption and all values were considered to be within normal limits.

BODY WEIGHT
Treatment had no effect on bodyweight and all values were considered to be within normal limits.

Interpretation of results:

not classified

Conclusions:

It can be concluded that the LD50 in Macaca fascicularis is > 100 mg/kg bw.

Executive summary:

Ten male Macaca fascicularis were exposed to a single dose of 100 mg/kg bw test substance via oral gavage followed by a 14-day observation period. 4 out of 10 animals died within 24 hours after dosing. Vomiting, lethargy and semi-collapse were observed. All surviving animals began to recover between 4 and 6 hours after dosing. No treatment related effects were observed on body weight and food consumption. Post mortem examination of one animal that failed to vomit showed grey/green fluid in the lungs and the trachea indicating that this animal had inhaled vomit. Under the conditions of the test it can be concluded that the LD50 in Macaca fascicularis is > 100 mg/kg bw.

Reference 4

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

Seven Rhesus Monkeys and two Marmosets were exposed on varying numbers of occasions to different concentrations test substance. Dosages of 0.025, 0.05, 0.01, 0.2, 0.3, 0.4, 0.5, 0.6, and/or 1.0 mg/kg test substance were administered by oral gavage.

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Species:

other: Rhesus Monkey and Marmoset

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: Monkeys initial weight ranged from 4.2 - 14.0 kg. The two marmosets were 250 (male) and 400 (female) g.

Route of administration:

oral: gavage

Vehicle:

other: Nonylphenolethylene oxide condensate 0.1%, Sodium salt of sulphated cetyl/oleyl alcohol mixture 0.1% , and polyglyceryl ricinoleate 0.1% to 100% distilled water

Doses:

0.025, 0.05, 0.01, 0.2, 0.3, 0.4, 0.5, 0.6, and 1.0 mg/kg

No. of animals per sex per dose:

The experiment was performed with 7 monkeys and 2 marmosets in total.

Control animals:

no

Details on study design:

The animals were repeatedly doses with different dosages.

Sex:

male/female

Dose descriptor:

discriminating dose

Effect level:

1 mg/kg bw

Based on:

test mat.

Mortality:

No mortality was reported.

Clinical signs:

other: See any other information on results incl. tables.

Rhesus Monkey 561, male, weight 14.0 kg:

6.1.69: dosed 1 mg/kg; sick at 10 mins.

17.3.69: dosed 0.1 mg/kg; sick at 10 mins and 20 mins.

19.3.69: dosed 0.025 mg/kg; slightly sick at 10 mins.

20.3.69: dosed 0.025 mg/kg; slightly sick at 10 mins and 25 mins.

Rhesus Monkey 613, male, weight 9.5 kg:

6.1.69: dosed 1 mg/kg; squirming round cage on stomach, sick from 10 - 30 mins, tranquilised for about 2 hours.

17.3.69: dosed 0.1 mg/kg; sick at 10 mine, tranquilised for 1 hour.

19.3.69: dosed 0.025 mg/kg; Unaffected

20.3.69: as above

21.3.69: dosed 0.05 mg/kg; mild reaction, tranquilised. Dosed 0.1 mg/kg in afternoon; no symptoms.

24.3.69: dosed 0.1 mg/kg; tranquilised but not sick.

25.3.69: dosed 0.1 mg/kg; tranquilised.

26.3.69: dosed 0.1 mg/kg; slightly tranquilised, fed before dosing from today.

27.3.69: dosed 0.2 mg/kg; slightly tranquilised.

28.3.69: dosed 0.3 mg/kg; slightly tranquilised.

29.3.69: as above

30.3.69: as above

31.3.69: dosed 0.4 mg/kg; tranquilised

1.4.69: dosed 0.5 mg/kg; tranquilised. Not fed before dosing from today.

2.4.69: dosed 0.5 mg/kg; very sick at 20 mins.

3.4.69: dosed 0.4 mg/kg; sick at 20 mins.

4.4.69: dosed 0.3 mg/kg in distilled water; unaffected.

5.4.69: dosed 0.3 mg/kg in distilled water; unaffected.

6.4.69: dosed 0.4 mg/kg in distilled water; unaffected.

7.4.69: dosed 0.4 mg/kg in distilled water; unaffected, sick after 25 mins.

Rhesus Monkey 640, female, weight 4.4.kg:

20.3.69: dosed 0.025 mg/kg; unaffected.

21.3.69: dosed 0.05 mg/kg; unaffected. Dosed 0.1 mg/kg in afternoon; unaffected.

24.3.69: dosed 0.1 mg/kg; sick after 15 mins.

25.3.69: dosed 0.1 mg/kg; sick after 1.25 hours.

26.3.69: dosed 0.1 mg/kg; unaffected. Fed before dosing.

27.3.69: dosed 0.2 mg/kg; unaffected.

28.3.69: dosed 0.3 mg/kg; sick by 5 hours.

1.4.69: Not fed before dosing. Dosed i.v. slowly at 0.05 mg/kg (in dispersing agent) and after 4 mins. given a further 0.05 mg/kg. Heaving and sick from 15 - 25 mins. Sick again at 3 and 3,5 hours.

Rhesus Monkey 614, male, weight 6.8 kg.

20.3.69: dosed 0.025 mg/kg; unaffected.

21.3.69: dosed 0.05 mg/kg; unaffected. Dosed 0.1 mg/kg in afternoon; unaffected.

24.3.69: dosed 0.1 mg/kg; not observed to be sick, but fluid in cage after 2,5 hours.

25.3.69: dosed 0.1 mg/kg; slightly tranquilised.

26.3.69: dosed 0.1 mg/kg; slightly tranquilised. Fed before dosing from today.

27.3.69: dosed 0.2 mg/kg; hardly affected

28.3.69: dosed 0.3 mg/kg; no symptoms but suddenly sick at 5 hours.

29.3.69: dosed 0.3 mg/kg; no symptoms

30.3.69 dosed 0.3 mg/kg; unaffected

31.3.69 dosed 0.4 mg/kg; unaffected

1.4.69 dosed 0.5 mg/kg; sick at 1 hour. 1 hour later dosed again at 0.5 mg/kg; sick 2 hours later.

2.4.69 dosed 0.4 mg/kg; unaffected.

3.4.69 dosed 0.4 mg/kg; unaffected.

4.4.69 dosed 0.4 mg/kg in distilled water; unaffected .

5.4.69 dosed 0.5 mg/kg in distilled water; sick after 35 mins and again in the afternoon

6.4.69 dosed 0.4 mg/kg in distilled water; sick after 74 mins.

7.4.69 dosed 0.4 mg/kg in distilled water; unaffected.

Rhesus monkey A, female, weight 4.2 kg:

1.4.69: dosed 0.1 mg/kg; very sick after 15 mins. slightly tranquilised for 1.5 hours.

Rhesus monkey B, female, weight 4.3 kg:

1.4.69: dosed 0.1 mg/kg; unaffected.

2.4.69: dosed 0.1 mg/kg; unaffected.

3.4.69: dosed 0.2 mg/kg; tranquilised, sick at 25 mins.

4.4.69: dosed 0.1 mg/kg; unaffected.

5.4.69: dosed 0.1 mg/kg; unaffected.

6.4.69: dosed 0.2 mg/kg; unaffected.

7.4.69: dosed 0.3 mg/kg; unaffected.

Rhesus monkey C, sex not recorded, weight 5.5 kg:

26.3.69: dosed 0.05 mg/kg; unaffected.

27.3.69: dosed 0.1 mg/kg; unaffected.

28.3.69: dosed 0.2 mg/kg; sick by 5 hours.

29.3.69: dosed 0.2 mg/kg; unaffected.

30.3.69: dosed 0.2 mg/kg; sick about 5 hours.

31.3.69: dosed 0.2 mg/kg; sick at 3 hours.

1.4.69: dosed 0.2 mg/kg not fed before dosing; sick at ¾ hour. 1 ¼ hours later dosed again at 0.2 mg/kg. Sick 1 hour 20 mins later.

Rhesus monkey D, sex not recorded, weight 5.2 kg:

26.3.69: dosed 0.05 mg/kg; unaffected.

27.3.69: dosed 0.1 mg/kg; unaffected.

28.3.69: dosed 0.2 mg/kg; unaffected.

29.3.69: dosed 0.2 mg/kg; unaffected.

30.3.69: dosed 0.2 mg/kg; sick about 5 hours.

31.3.69: dosed 0.2 mg/kg; unaffected.

1.4.69: as above. Not fed before dosing.

2.4.69: dosed 0.3 mg/kg; unaffected.

3.4.69: as above.

4.4.69: as above.

5.4.69: dosed 0.4 mg/kg; unaffected.

6.4.69: dosed 0.4 mg/kg; sick 28 mins.

7.4.69: dosed 0.4 mg/kg; sick 2.5 hours.

Marmoset A, male, weight 250 g and marmoset B, female, weight 400 g:

3.4.69: dosed 0.1 mg/kg in distilled water; unaffected.

4.4.69: dosed 0.2 mg/kg in distilled water; male sick 15 mins, female not exactly sick but frothing.

5.4.69: dosed 0.1 mg/kg in distilled water; unaffected.

6.4.69: dosed 0.2 mg/kg in distilled water; salivation but not sick

7.4.69: dosed 0.3 mg/kg in distilled water; unaffected.

8.4.69: dosed 0.4 mg/kg in distilled water; unaffected

9.4.69: dosed 0.6 mg/kg in distilled water; both sick at 15 mins.

Interpretation of results:

not classified

Conclusions:

Emesis occurred 33, 0, 21, 42, 13, 33, 80, 100, and 100% of the cases after administration of 0.025, 0.05, 0.01, 0.2, 0.3, 0.4, 0.5, 0.6, and 1.0 mg/kg test substance, respectively.

Executive summary:

7 Rhesus Monkeys and two Marmosets were repeatedly exposed to different concentrations test substance. Dosages of 0.025, 0.05, 0.01, 0.2, 0.3, 0.4, 0.5, 0.6, and/or 1.0 mg/kg test substance were administrated by oral gavage. The animals were observed for clinical signs with emphasis on emesis. Emesis occurred 33, 0, 21, 42, 13, 33, 80, 100, and 100% of the cases after administration of 0.025, 0.05, 0.01, 0.2, 0.3, 0.4, 0.5, 0.6, and 1.0 mg/kg test substance, respectively.

Reference 5

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

Groups of 8 pigs were fed twice a day for two days with diets containing 10, 20, and 40 g test substance/ton diet. The pigs were observed for quantity of food eaten and emesis.

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Species:

pig

Strain:

not specified

Sex:

not specified

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Diet: standard pig-fattening ration
- Weight at study initiation: ca. 20 kg

Route of administration:

oral: feed

Vehicle:

not specified

Details on oral exposure:

- Administration: Groups of 8 pigs were fed twice a day for two days diets containing 10, 20, and 40 g/ton. These rates were chosen to give 0.1 - 1.0 mg/kg to 20 kg pigs.
- The pigs were provided with 500 g of the medicated diet twice daily for 2 days.

Doses:

4, 10, 20, 40 g/ton equivalent to 0.1, 0.25, 0.5, and 1.0 mg/kg/pig

No. of animals per sex per dose:

8

Control animals:

no

Details on study design:

- Duration of observation period: for two days during treatment.
- Observations: quantity of food eaten and emesis.

Sex:

not specified

Dose descriptor:

discriminating dose

Effect level:

1 mg/kg bw

Based on:

test mat.

Mortality:

No mortality was reported

Clinical signs:

other: EMESIS - In 5/8, 3/8 0/8, and 0/8 pigs emesis was observed in the 1.0, 0.5, 0.25, and 0.1 mg/kg dose groups, respectively. FOOD CONSUMPTION - 8/8, 8/8, 6/8 and 0/8 animals refused the died in the 1.0, 0.5, 0.25, and 0.1 mg/kg dose groups, respectively.

Interpretation of results:

not classified

Conclusions:

In 5/8, 3/8 0/8, and 0/8 pigs emesis was observed in the 1.0, 0.5, 0.25, and 0.1 mg/kg dose groups, respectively.

Executive summary:

Groups of 8 pigs were fed twice a day for two days diets containing 4, 10, 20, and 40 g/ton (equivalent to 0.1, 0.25, 0.5, and 1.0 mg/kg). The pigs were observed for quantity of food eaten and emesis. No mortality was observed, but in 5/8, 3/8 0/8, and 0/8 pigs emesis was observed in the 1.0, 0.5, 0.25, and 0.1 mg/kg dose groups, respectively.

Reference 6

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

Two male Macaca fascicularis monkeys were repeatedly dosed with 5, 10, 20, and 30 mg/kg bw test substance via oral gavage followed by a 14-day observation period.

GLP compliance:

no

Test type:

other: 2 animals were repeatedly exposed to incerasing concentrations of test substance

Limit test:

no

Species:

monkey

Strain:

other: Macaca fascicularis

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: approximately 2-5 years
- Weight at study initiation: mean 4.21 kg
- Fasting period before study: at least 16 hours
- Housing: individually in 62 cm x 62 cm x 87 cm aluminium and stainless steel primate cages.
- Diet: 150 g dry diet consisting of a 1:1 ratio of F.P.I and Mazuri Primate Diet, 2 x 25 g Bonio biscuits, a daily slice of brown bread and on average 4 out of 7 days a weighed quantity of fresh fruit of vegetable produce.
- Water: tap water, ad libitum. Blackcurrant Syrup B.P.C. and Cytacon vitamin B12 liquid, 20 mL of each, was added to a litre of tap water.
- Acclimation period: at least 2 weeks

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3
- Air changes: well-ventilated holding area
- Photoperiod (hrs dark / hrs light): daylight and artificial light during working hours

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

MAXIMUM DOSE VOLUME APPLIED:
All doses were made up to a total volume of 100 mL with tap water.

DOSAGE PREPARATION:
Aqueous dosing solutions containing 5 mg/L were prepared.

Doses:

PRETEST
1 mg/kg and 2 mg/kg (20 days later)

TOXICITY TEST
Day 1, 5 mg/kg; day 13: 10 mg/kg; day 15: 20 mg/kg; day 21: 30 mg/kg

No. of animals per sex per dose:

2

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Examinations performed: clinical signs including vomiting behaviour (continuously for the first 6 hours after dosing and then twice daily), body weight (weekly), food consumption (daily), post mortem examination of one animal.

Sex:

male

Dose descriptor:

discriminating dose

Effect level:

30 mg/kg bw

Based on:

test mat.

Remarks on result:

other: The substance causes emesis therefore it is unlikely that the complete dose will be available for uptake.

Mortality:

No mortality observed

Clinical signs:

other: EMESIS, PRETEST - Powerful and repeated vomiting at both 1 and 2 mg/kg was found. CLINICAL SIGNS, TOXICITY TEST Vomiting was observed in both animals within a few minutes at all doses except in one animal after administration of 10 mg/kg bw test substanc

Interpretation of results:

not classified

Conclusions:

It can be concluded that the LD50 in Macaca fascicularis is > 30 mg/kg bw.

Executive summary:

The same two male Macaca fascicularis were repeatedly dosed with increasing doses (5, 10, 20, and 30 mg/kg bw test substance) via oral gavage followed by a 14 -day observation period. No mortality was observed. Vomiting was observed in both animals within a few minutes at all doses except in one animal after administration of 10 mg/kg bw test substance. Vomiting motions continued only for a few minutes after which the animals became lethargic and, at doses of 10 mg/kg and above collapsed by about 30 minutes after dosing. The animals remained unconscious or semi-conscious for approximately 1 hour and then made a gradual and complete recovery. Under the conditions of the test it can be concluded that the LD50 in Macaca fascicularis is > 30 mg/kg bw.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating dose

Value:

100 mg/kg bw

Quality of whole database:

non-GLP compliant pre-guideline study, Klimisch 2

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

Five rats per sex were exposed to a single dermal dose of 2000 mg/kg bw test substance under occlusive conditions. The test substance was removed with clean warm water after the exposure period followed by a 14-day observation period.

GLP compliance:

no

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

other: albino

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 222 - 250 g for males and 168 - 192 g for females

Type of coverage:

occlusive

Vehicle:

water

Details on dermal exposure:

REMOVAL OF TEST SUBSTANCE
- Washing: yes, with clean warm water

TEST MATERIAL
- For solids, paste formed: yes

Duration of exposure:

24 hours

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
- Examinations performed: clinical signs (daily), skin irritation (daily), body weight, gross pathology.

Sex:

male/female

Dose descriptor:

discriminating dose

Effect level:

2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality observed

Clinical signs:

other: The signs of toxicity (stains around nose, urinary incontinence, diarrhoea and signs of diarrhoea) observed in some animals up to day three were probably due to the occlusive dressings.

Gross pathology:

No macroscopic abnormalities were detected at necropsy.

Other findings:

Slight erythema was observed in one male rat on day 2. No signs of skin irritation were observed during the study.

Conclusions:

It can be concluded that the dermal acute LD50 in rats is > 2000 mg/kg bw.

Executive summary:

Five rats per sex were exposed to a single dermal dose of 2000 mg/kg bw test substance under occlusive conditions for 24 hours. The test substance was removed with clean warm water after the exposure period followed by a 14-day observation period. No mortality was observed. The signs of toxicity (stains around nose, urinary incontinence, diarrhoea and signs of diarrhoea) observed in some animals up to day three were probably due to the occlusive dressings. All animals regained their initial body weights by the end of the study and no macroscopic abnormalities were detected at necropsy. Slight erythema was observed in one male rat on day 2. No signs of skin irritation were observed during the study. Under the conditions of the test it can be concluded that the dermal acute LD50 value in rats is > 2000 mg/kg bw.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating dose

Value:

2 000 mg/kg bw

Quality of whole database:

non-GLP compliant pre-guideline study, Klimisch 4

Additional information

Acute oral

Multiple non-GLP and pre-guideline studies in several species are available for oral acute toxicity. The test substance is a known emetic in humans (Bayliss, 1973). Therefore tests in vomiting species are most relevant. Both Davison (1988) and Farrell (1970) used non-vomiting species, rat and mice. Tests performed with these species were considered supporting, since the dosed test substance is likely more available for absorption compared to vomiting species. The remaining studies are also non-GLP and pre-guideline studies performed in vomiting species; monkeys, dogs and pigs. Although the studies have limitations in study design and reporting, these studies are sufficient to draw a conclusion regarding oral toxicity in a weight of evidence approach.

Monkeys

Purser et al. (1978), exposed 10 male Macaca fascicularis to a single dose of 100 mg/kg bw test substance via oral gavage followed by a 14-day observation period. 4 out of 10 animals died within 24 hours after dosing. Vomiting, lethargy and semi-collapse were observed. All surviving animals began to recover between 4 and 6 hours after dosing. No treatment related effects were observed on body weight and food consumption. Post mortem examination of one animal that failed to vomit showed grey/green fluid in the lungs and the trachea indicating that this animal had inhaled vomit. The combination of a collapsed state and emetic activity can present a hazard. The chances of animals inhaling its own vomit are high. The observed deaths are most likely secondary effects of the animals inhaling vomit. Under the conditions of the test it can be concluded that the LD50 in Macaca fascicularis is >100 mg/kg bw.

Todd (1977) investigated emesis in seven Rhesus Monkeys and two Marmosets. The animals were repeatedly exposed to different concentrations of test substance. Dosages of 0.025, 0.05, 0.01, 0.2, 0.3, 0.4, 0.5, 0.6, and/or 1.0 mg/kg bw test substance were administered by oral gavage. The animals were observed for clinical signs with emphasis on emesis. Emesis occurred in 33, 0, 21, 42, 13, 33, 80, 100, and 100% of the cases after administration of 0.025, 0.05, 0.01, 0.2, 0.3, 0.4, 0.5, 0.6, and 1.0 mg/kg bw test substance, respectively. No mortality was reported.

Cobb et al. (1979) exposed the same two male Macaca fascicularis with doses of 5, 10, 20, and 30 mg/kg bw test substance via oral gavage followed by a 14 -day observation period. No mortality was observed. Vomiting was observed in both animals within a few minutes at all doses except in one animal after administration of 10 mg/kg bw test substance. Vomiting motions continued only for a few minutes after which the animals became lethargic and, at doses of 10 mg/kg bw and above collapsed by about 30 minutes after dosing. The animals remained unconscious or semi-conscious for approximately 1 hour and then made a gradual and complete recovery. Under the conditions of the test it can be concluded that the LD50 in Macaca fascicularis is >30 mg/kg bw.

Dogs

Brammer and Robinson (1986) used dogs, another vomiting species, to investigate the emetic effect of the test substance after oral dosing. Three beagles were dosed with 3 mg/kg test substance by oral gavage. The dogs were pre-treated differently to provide differing stomach conditions for dosage of the test substance to investigate the effect of stomach status on emesis. One dog was fed, 350 g laboratory diet A, 30 minutes pre-dose. Another dog was fed 50 mL COMPLAN solution (6 g in 50 mL water) by gavage immediately pre-dose. The last dog was dosed on an empty stomach. The dogs were observed continuously for 1 hour after dosing and then regularly for the remainder of the working day. No mortality was observed. The test substance caused emesis in all 3 dogs regardless of the stomach state. The effect was most severe when dosed on an empty stomach.

In a second study by Brammer and Robinson (1986), one beagle per sex/dose was dosed with 0, 0.1, 0.5, 1.0, 3.0, 10.0, or 20.0 mg/kg bw test substance (corrected for impurity) by oral gavage and observed for 7 days. No mortality occurred. When dosed orally to dogs, the test substance caused emesis at dose levels in the range of 0.5 mg/kg bw to 20 mg/kg bw. The onset of vomiting was dose related being slowest at 0.5 mg/kg bw (25-27 minutes after dosing) and most rapid at 10 and 20 mg/kg bw (5 minutes in each case). The severity of effects was also dose-related and severe vomiting was seen at dose levels of 3 mg/kg and above. The female dog dosed with 20 mg/kg was more severely affected than any other dog and did not fully recover until 6 hrs after dosing. Apart from the immediate effects of the test substance on the gastrointestinal tract there were no other adverse effects of treatment.

Pigs

Finally information on a third vomiting species is available. Groups of 8 pigs were fed twice a day for two days diets containing 10, 20, and 40 g/ton. These rates were chosen to give doses of 1.0, 0.5, 0.25, and 0.1 mg/kg bw. The pigs were observed for quantity of food eaten and emesis. No mortality was reported in this study (Todd, 1977).

Based on these results it can be concluded that the main acute oral effect of the test substance at doses up to 100 mg/kg body weight in vomiting species is emesis. The deaths in the experiment at 100 mg/kg bw in the Macaca fascicularis are most likely secondary effects of the animals inhaling vomit in an unconscious state. In this experiment all surviving animals recovered.

Studies investigating blood plasma levels confirmed the absorption and systemic availability of the test substance after oral dosing in rats, guinea-pigs, dogs, and humans (Case and Dunlop, 1977; Farrell, 1970a; Bayliss, 1973). Furthermore intravenous dosing studies indicated that the emetic effect of the test substance depends on blood plasma levels of the test substance (Farrell, 1970a; Farrell, 1970b; Case and Dunlop, 1977). Plasma levels of 0.4 µg/L as a result of intravenous dosing caused emesis in beagles and confirm that emesis is a systemic effect (Case and Dunlop, 1977). A volunteer study found an emetic response in 0/2, 4/7, 1/2 and 1/1 of the volunteers after a single oral dose of 1, 2, 4, 8 mg (corresponding with ca. 0.015, 0.03, 0.06 and 0.11 mg/kg bw), respectively. Plasma levels of two volunteers dosed with 4 mg (ca. 0.06 mg/kg bw) were determined 1, 2 and 3 hours after dosing. Blood concentrations were 0.081, 0.041, 0.034 µg/mL and 0.045, 0.056, 0.044 µg/mL after 1, 2, and 3 hours, respectively. This indicates that the test substance can already induce emesis in humans at concentrations far below 100 mg/kg bw. The severity of the vomiting effects increases with increasing oral dose and subsequent increasing plasma levels. Additional to emesis the test substance can reduce gastric emptying in monkeys, mice and rats that reduces the content of the stomach that passes further into the gastro intestinal tract (Wright et al., 1979). Studies with an increased oral dose will most likely increase emesis and in combination with reduced gastric emptying, further absorption of the test compound into the gastro-intestinal tract will be limited. Finally, the absorbed test substance can be excreted as the parent compound or as its non-conjugated metabolite via urine and faeces (Farrell, 1970a). The biological half-life in dogs was determined to be <3 hours. Based mainly on the emetic effect but also on the reduction of gastric emptying and elimination of the test substance at concentration below 100 mg/kg bw it can be concluded that increasing the dose above 100 mg/kg bw is not likely to increase systemic availability and therefore further testing is scientifically unjustified.

Acute dermal

Five rats per sex were exposed to a single dermal dose of 2000 mg/kg bw test substance under occlusive conditions for 24 hours. The test substance was removed with clean warm water after the exposure period followed by a 14-day observation period. No mortality was observed. The signs of toxicity (stains around nose, urinary incontinence, diarrhoea and signs of diarrhoea) observed in some animals up to day three were probably due to the occlusive dressings. All animals regained their initial bodyweights by the end of the study and no macroscopic abnormalities were detected at necropsy. Slight erythema was observed in one male rat on day 2. No signs of skin irritation were observed during the study. Under the conditions of the test it can be concluded that the dermal acute LD50 value in rats is >2000 mg/kg bw.

Acute inhalation

No studies are available regarding acute inhalation toxicity. Inhalation followed by absorption of the test substance will result in emesis in vomiting species. Humans are most sensitive to the emetic effects and vomiting occurs at 2 – 8 mg (ca. 0.03 – 0.11 mg/kg bw). The test substance will be more available for absorption via inhalation compared to oral exposure since the dose cannot be reduced by vomiting. However emesis will be induced at similar plasma levels of the test substance independent of the exposure route. Because of great discomfort as a result of emesis it is highly unlikely that exposed subjects will stay in the exposure area, interrupting exposure. Thus in practice the highest systemic available concentration by inhalation exposure that can be reached is similar to that after oral exposure. No substance related adverse effects were observed in vomiting species after oral exposure (except emesis) and therefore no adverse effects are expected after inhalation exposure of vomiting species.

Justification for classification or non-classification

Based on the observed clinical signs (emesis) up to 100 mg/kg bw in the acute oral toxicity studies and the absence of adverse effects at 2000 mg/kg in the acute dermal toxicity study, the test substance is not classified according to the EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008.