zinc, 5,5'-azobis-2,4,6(1H,3H,5H)-pyrimidinetrione complexes and melamine

Repeated dose toxicity: oral

Administrative data

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study under GLP condition

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2014

Report date:

2014

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity Study in Rodents)

Deviations:

yes

Remarks:

additional control rats and additional rats dosed with 1000 mg/kg bw/day serving as recovery group because they were maintained after termination of treatment for 14 days

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Azo zinc pigment complex - melamine compound

IUPAC Name:

Azo zinc pigment complex - melamine compound

Test material form:

other: brown powder

Details on test material:

Molecular weight 615.79
Lot no.BOS3479-3423
purity/content: 100 %

Test animals

Species:

rat

Strain:

Crj: CD(SD)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 5 week
- Weight at study initiation:
males: 115.0 - 128.9 g
females: 85.6 - 109.8 g
- Fasting period before study:
- Housing: individually
- Diet ad libitum
- Water ad libitum
- Acclimation period:

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22
- Humidity (%): 50
- Air changes (per hr): 10 - 15
- Photoperiod (hrs dark / hrs light): 12 / 12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: 0.5 % carboxymethylcellulose

Details on oral exposure:

Azo zinc complex pigment melamine compound was given to male and fenale rats by gavage in doses. of 0, 100, 330, or 1000 mf/kg bw/day suspended in 0.5 % carboxymethylcellulose over a period of 28 days. For the vehicle control as well as for the high dose group extra 5 aminmals per sex were used as recovery group.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The stability and homogenicity of prepared test suspensions were confirmed by the concentration analysis validation and stability test;
tge suspension is stable for 7 days in the refrigerator and of good homogenicity.

Duration of treatment / exposure:

28 days

Frequency of treatment:

daily

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 100, 330, 1000 mg/kg bw/day
Basis:

No. of animals per sex per dose:

5

Control animals:

yes, concurrent vehicle

Details on study design:

Azo zinc complex pigment melamine compound was given to male and fenale rats by gavage in doses. of 0, 100, 330, or 1000 mf/kg bw/day suspended in 0.5 % carboxymethylcellulose over a period of 28 days. For the vehicle control as well as for the high dose group extra 5 aminmals per sex were used as recovery group.
--Clinical signs were reported once a day
--Body weight, food consumption, detailed clinical observations, observations of open field were recorded weekly
--urine analysis, ophthalmology, sensory reactivity, grip strength and motor activity were examined in the last week, i.e. week 4, of administration period
--Hematology and blood biochemistry was evaluated at the end of the administration period
Recovery group:
--Motor activity, hematology, blood biochemistry at the end of recovery period

--Gross necropsy, organ weight, and histopathology was evaluated at the end of the administration period
Recovery group
--necdropy , organ weight were also examined at the end of recovery period

Positive control:

no

Examinations

Observations and examinations performed and frequency:

--Clinical signs were reported once a day
--Body weight, food consumption, detailed clinical observations, observations of open field were recorded weekly
--urine analysis, ophthalmology, sensory reactivity, grip strength and motor activity were examined in the last week, i.e. week 4, of administrationperiod
--Hematology and blood biochemistra was evaluated at the end of the administration period
Recovery group:
--Motor activity, hematologym blood biochemistry at the end of recovery period

Sacrifice and pathology:

--Gross necropsy, organ weight, and histopathology was evaluated at the end of the administration period
Recovery group
--necdropy , organ weight were also examined at the end of recovery period

Statistics:

Levene's test, One Way ANOVA analysis, Scheffe's multiple comparison test, Dunnett's T3 test, F test, Student t-test, Mann.whitney test

Results and discussion

Results of examinations

Details on results:

No compound related adverse effects were observed on
-- mortality and clinical signs
Evidence of coompound colored feces was noted for all dosaage group animals during the administeration period indicating that the test substance is excreted directly via feces without relevant systemic absorption. Referring to recovery group: this finding disappeared and rats recovered to normal within the 14 day period Therefore this finding is regarded to be test substance related but not as an adverse effect

No compound related adverse effects were observed on
--detailed clinical observations: behavior
--sensory reactivity assessment and grip strength
--.motor activity
Statistically significant decrease (p<0.01) was observed at the time of 50-60 min in all males of the administration group
In females of the recovery group statistically significant increase (p<0.05) was observed at the times of 10-20 and 20-30 min
These sporadic statistically significant observations at a few time intervals were not dose related and/or not consistent over time and , consequently,
not considered to be compound related

No compound related adverse effects were observed on
--body weight
--food consumption
--urine analysis
--ophthalmology
--hematological analysis
in the test animals no statistically significant difference to the control group
recovery group:
males: Platelet count (PLT) was statistically significant decreased (p<0.05) and protrombin time (PT) increased (p<0.05)
females: Monocytes percentage was statisticlaly increased (p<0.05)
As these observations were seen only in the recovery animals these observations were not regarded to be compound related
--blood biochemical analysis
in test males dosed with 1000 mg/kg bw aspartate aminotransferases (AST) was statistically significant decreased (p<0.05)
These observations were not considerd to be compound related because the observations were not dose related an/or different in different genders and not in recovery males.

No compound related adverse effects were observed at necropsy
--gross pathological evaluation
--organ weights:
-absolute organ weights
in test groups there were no adverse findings
recovery group, males thyroid gland significantly decreased (p<0.01); females no findings
-relative organ weights
in test groups no adverse findings
recovery group, males, kidneys significantly increased (p<0.05) , thyroid gland significantly decreased (p<0.01)
Since these observations were not dose dependent and/or not consistent over gender and/or only observed in recovery group they were not considered to be compound related
--no test substance related histopatholoical lesions were observed in the high dose group

Effect levels

Dose descriptor:

NOAEL

Effect level:

1 000 mg/kg bw/day (actual dose received)

Sex:

male/female

Basis for effect level:

other: treatment related adverse effects were not observed

Target system / organ toxicity

Critical effects observed:

not specified

Applicant's summary and conclusion

Executive summary:

This study was performed to investigate the systemic toxicity on male and female rats followed 28 consecutive days repeated oral dosing of Azo zinc complex pigment - melamine compound via gavage at dose levels of 0, 100, 330, and 1000 mg/kg bw/day suspended in 0.5% carboxy methylcellulose. The study was conducted in compliance wtih OECD TG 407 under GLP conditions. In addition recovery groups (0 and 1000 mg/kg bw/day) were maintained without dosing for a further 14 days after administration period to evaluate the reversibility of any potential effects.

No animal died during the treatment period and in the recovery period thereafter. Azo zinc complex pigment - melamine compound was well tolerated. The evidence of compound colored feces was noted in all dosage groups during administration period but disappeared during recovery period. This observation indicated that absorption of Azo zinc complex pigment - melamine compound is limited. No

treatment related adverse effects could be determined during hematological and blood biochemical analysis or gross and histopathological examinations. Therefore, the NOAEL of Azo zinc complex pigment - Melamine compound is considered to be 1000 mg/kg bw/day