P 16513

Repeated dose toxicity: oral

Administrative data

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

August 13 - October 09, 2007

Reliability:

1 (reliable without restriction)

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

see field below

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.7 (Repeated Dose (28 Days) Toxicity (Oral))

Deviations:

yes

Remarks:

see field below

Principles of method if other than guideline:

Functional observation results of males at 50 mg/kg/day (animal numbers 11-15) were not recorded. However, sufficient functional observation results were available for evaluation and the study integrity was not adversely affected.

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Strontium 4-chloro-2-[2-hydroxy-6-sulfonatonaphthalen-1-yl)diazenyl]benzoate

Cas Number:

474814-88-5

Molecular formula:

C17H9ClN2O6SSr

IUPAC Name:

Strontium 4-chloro-2-[2-hydroxy-6-sulfonatonaphthalen-1-yl)diazenyl]benzoate

Test material form:

solid: nanoform, no surface treatment

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

according to guideline

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

oral via gavage

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The concentrations analysed in the formulations of Group 2 (50 mg/kg bw/d), Group 3 (250 mg/kg bw/d) and Group 4 (1000 mg/kg bw/d) were in agreement with target concentrations (i.e. mean accuracies between 85% and 115%).
No test substance was detected in the Group 1 formulation (vehicle control).
The formulations of Group 2 and Group 4 were homogeneous (i.e. coefficient of variation ≤ 10%) (not determined for Group 3).

Duration of treatment / exposure:

28 days.

Frequency of treatment:

Once daily, 7 days per week, approximately the same time each day with a maximum of 4 hours difference between the earliest and latest dose.

Doses / concentrations

Doses / concentrations 1

Remarks:

Doses / Concentrations:
50 mg/kg bw/d
Basis:
actual ingested

Doses / concentrations 2

Remarks:

Doses / Concentrations:
250 mg/kg bw/d
Basis:
actual ingested

Doses / concentrations 3

Remarks:

Doses / Concentrations:
1000 mg/kg bw/d
Basis:
actual ingested

No. of animals per sex per dose:

5

Control animals:

yes, concurrent vehicle

Details on study design:

Doses are based on dose-range-finding

Examinations

Sacrifice and pathology:

Necropsy:
ORGAN WEIGHTS: Yes: Adrenal glands, Brain, Epididymides, Heart, Kidneys, Liver, Ovaries, Spleen, Testes, Thymus
Histopathology: yes
Gross Pathology: yes

Statistics:

- If the variables could be assumed to follow a normal distribution, the Dunnett-test1 (many-to-one t-test) based on a pooled variance estimate was applied for the comparison of the treated groups and the control groups for each sex.
- The Steel-test2 (many-to-one rank test) was applied when the data could not be assumed to follow a normal distribution.
- The exact Fisher-test3 was applied to frequency data.
All tests were two-sided and in all cases p < 0.05 was accepted as the lowest level of significance.

Results and discussion

Results of examinations

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

no effects observed

Behaviour (functional findings):

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

no effects observed

Effect levels

Dose descriptor:

NOAEL

Effect level:

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

Sex:

male/female

Basis for effect level:

other: no effects at highest tested dose level

Target system / organ toxicity

Critical effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

Treatment up to 1000 mg/kg/day was well tolerated; no toxicologically relevant changes in clinical signs or functional observations were noted, and body weight and food intake appeared unaffected by treatment. Blood analyses revealed a few changes which were considered not to represent an adverse effect on organ function, taking into account their slight nature and the absence of corroborative morphological changes. At the end of the treatment period, these changes included lower relative lymphocyte counts and lower prothrombine time (PT), higher relative L- reticulocyte counts and mean corpuscular haemoglobin concentration (MCHC), in males at 50 and/or 250 mg/kg/day, and lower methaemoglobin levels in females at 1000 mg/kg/day. At the end of the recovery period, these changes consisted of lower relative L-reticulocyte counts, and higher relative M-reticulocyte counts and relative monocyte counts in males at 1000 mg/kg/day.
No treatment-related toxicologically significant changes were noted in any of the remaining parameters investigated in this study (i.e. macroscopic examination, organ weights, and microscopic examination).
NOAEL = 1000 mg/kg/day.