Registration Dossier

Administrative data

Endpoint:
sub-chronic toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1989-01-17 to 1989-02-13
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study

Data source

Referenceopen allclose all

Reference Type:
study report
Title:
Unnamed
Year:
1989
Report date:
1989
Reference Type:
study report
Title:
Unnamed
Year:
2001
Report date:
2001

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity Study in Rodents)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method B.7 (Repeated Dose (28 Days) Toxicity (Oral))
Deviations:
no
GLP compliance:
yes
Limit test:
yes

Test material

Constituent 1
Reference substance name:
10486-00-7
EC Number:
600-611-8
Cas Number:
10486-00-7
IUPAC Name:
10486-00-7
Constituent 2
Reference substance name:
Sodium perborate tetrahydrate
IUPAC Name:
Sodium perborate tetrahydrate
Details on test material:
-Physical state: Colourless crystals
-Purity: > 98 %
-Lot/batch No.: 10/10/88
-Stability under test conditions: Stable throughout the test according to Sponsor's information
-Storage condition of test material: Kept in closed container in a refrigerator
-Other: Solubility: 23 g/L (20°C); pH-value: 10.1 - 10.4 (2% solution, 20°C)

Test animals

Species:
rat
Strain:
other: Bor:WISW (SPFCpb)
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
-Source: Winkelmann, Borchen
-Age at study initiation: 7 weeks
-Weight at study initiation: males 139 - 173 g; females: 108 - 131 g
-Fasting period before study: no
-Housing: single in Macrolon cages type II
-Diet: ad lib.
-Water: ad lib.
-Acclimation period: 2 weeks

ENVIRONMENTAL CONDITIONS
-Temperature (°C): 20 - 22
-Humidity (%): 40 - 55
-Air changes (per hr): no data
-Photoperiod: 12 hrs dark /12 hrs light

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
other: 1 % aqueous tylose suspension
Details on oral exposure:
PREPARATION OF DOSING SOLUTIONS
Sodium Perborate Tetrahydrate was administered in a dose of 1000 mg/kg bw. The substance was suspended in a 1 % aqueous tylose suspension. The administration volume was 4.64 mg/mL kg bw, i.e. the content of the test item in suspension was 215 mg/mL. To prevent from sedimentation, the suspension was stirred during administration.

VEHICLE
-Justification for use and choice of vehicle: Tylose was used to achieve a uniform suspension
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Content and stability of the test item in the aqueous tylose suspension were examined by the Sponsor prior to the first administration. These results were found to be within acceptable limits.
Duration of treatment / exposure:
28 days
Frequency of treatment:
once daily (7 days per week)
Doses / concentrations
Remarks:
Doses / Concentrations:
1000 mg/kg b.w.
Basis:
other: actual (nominal) dose per kg bw
No. of animals per sex per dose:
5 m / 5 f
Control animals:
yes, concurrent vehicle
Details on study design:
Dose selection rationale:
The test item was administered orally during a dose-range finding study (23 days) at a dose of 1000 mg/kg bw/day. Only salivation was observed as clinical sign and two animals showed slight reddening of the glandular stomach. According to these findings a dose of 1000 mg/kg bw/day was selected for the definite study.

Post-exposure period: no

Rationale for selecting satellite groups: No recovery group selected
Positive control:
Not applicable

Examinations

Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
1 - 2 times daily incl. observations for mortality

DETAILED CLINICAL OBSERVATIONS: Yes
Daily check for clinical signs (behavioural changes, first occurrence, progress, intensity and duration of signs of toxicity)
Prior to study start and at termination: testing of reflexes (pain, pinna and corneal reflexes) as well as examinations of eyes, teeth, or hearing.

BODY WEIGHT: Yes
once weekly, starting with pre-study period

FOOD CONSUMPTION: Yes
once weekly

FOOD EFFICIENCY: No data

WATER CONSUMPTION: No data

OPHTHALMOSCOPIC EXAMINATION: Yes
prior to study start and at termination in all animals

HAEMATOLOGY: Yes
during week 4 in all animals
Anaesthetic used for blood collection: Yes (CO2 anaesthesia)
Animals fasted: no data
Parameters examined: RBC, Hct, Hb, WBC, MCH, MCHC, MCV, thrombocytes (platelets) and differential leucocyte count

CLINICAL CHEMISTRY: Yes
during week 4 in all animals
Animals fasted: no data
Parameters examined: Alanine aminotransferase, albumin, alkaline phosphatase, aspartate aminotransferase, BUN, Ca, Cl, CHE, CK, creatinine, gamma-glutamyltransferase, glucose, inorganic phosphorus, K, Na, total bilirubin, total cholesterol, total protein, triglycerides

URINALYSIS: Yes
during week 4 in all animals
Metabolism cages used for collection of urine: Yes
Animals fasted: no data
Parameters examined: bilirubin, glucose, haemoglobin, ketones, leucocytes, nitrite, osmolality, pH-value, protein, urobilinogen and microscopic sediment examination in animals whose urine state showed pathological changes in leucocytes, protein, or haemoglobin.
Sacrifice and pathology:
GROSS PATHOLOGY: Yes
all animals

HISTOPATHOLOGY: Yes
all animals
adrenal glands, bone (sternum), bone marrow smears, brain, caecum, colon, duodenum, heart, ileum, jejunum, kidneys, liver, lungs, ovaries, rectum, skin, spleen, stomach, testes
Statistics:
DUNNETT or STEEL-Test

Results and discussion

Results of examinations

Clinical signs:
effects observed, treatment-related
Mortality:
mortality observed, treatment-related
Body weight and weight changes:
effects observed, treatment-related
Food consumption and compound intake (if feeding study):
effects observed, treatment-related
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
no effects observed
Haematological findings:
effects observed, treatment-related
Clinical biochemistry findings:
effects observed, treatment-related
Urinalysis findings:
no effects observed
Behaviour (functional findings):
no effects observed
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Gross pathological findings:
effects observed, treatment-related
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Histopathological findings: neoplastic:
no effects observed
Details on results:
CLINICAL SIGNS AND MORTALITY
Salivation in almost all rats. Stilted gait, sunken sides and piloerection in one male. In 2 animals, piloerection during the last 4 days. No mortality.

BODY WEIGHT AND WEIGHT GAIN
Weight gain reduction in males at about 15 %

FOOD CONSUMPTION
Reduced in males up to 15 %

HAEMATOLOGY
Slight decrease of red blood cell parameters and increase of platelets in rats of both sexes. Decrease in white blood cell count in males due to reduction of absolute lymphocyte numbers.

CLINICAL CHEMISTRY
Possibly treatment-related changes present as reduction of total cholinesterase and protein (both sexes), albumin (males), cholesterol and calcium (females).

ORGAN WEIGHTS
Absolute organ weights of brain, heart, kidneys and testes were slightly reduced in males. Relative weights of adrenals were increased in males, relative liver weight was slightly increased in females.

GROSS PATHOLOGY
Reduced spleen size in treated males.

HISTOPATHOLOGY
NON-NEOPLASTIC: Mild test item-related reduction of the splenic parenchyma in males. Slight acanthosis and hyperkeratosis in the forestomach and hyperplasia of the fundic mucosa in males and females.

Effect levels

Dose descriptor:
NOAEL
Effect level:
< 1 000 mg/kg bw/day (actual dose received)
Sex:
male/female
Basis for effect level:
other: see 'Remark'

Target system / organ toxicity

Critical effects observed:
not specified

Any other information on results incl. tables

Dose level (mg/kg bw/day)

0

1000

Clinical signs (entire study)

Males / Females

 

salivation, piloerection

Body weights (g; group means at week 4)

Males

258.4

216.1*

Females

166.1

167.0

Food consumption (g/animal/d; group means during 4 weeks)

Males

19.7 - 20.8

16.2 - 18.1*/**

Females

14.4 - 14.8

13.8 - 14.7

Haematology (group means at week 4)

Males

 

 

Erythrocytes (pro pl)

6.94

6.05*

Haemoglobin (g/dL)

15.9

14.3*

Haematocrit (L/L)

0.449

0.384*

MCHC (g/dL)

35.4

37.3*

Platelets (pro nL)

1015

1175*

WBC (pro nL)

12.9

9.4*

Lymphocytes (pro nL)

11.36

8.19+

Females

 

 

Erythrocytes (pro pl)

6.60

5.71*

Haemoglobin (g/dL)

15.7

13.6*

Haematocrit

0.415

0.362*

Platelets (pro nL)

1020

1200*

Clinical chemistry (group means at week 4)

Males

 

 

Total bilirubin (umol/L)

2.68

3.42*

Total protein (g/L)

59.63

52.35*

AKP (IU/L)

445.52

311.30*

Creatinine (umol/L)

41.04

33.67*

Phosphorus (mmol/L)

3.09

3.42*

Cholinesterase (IU/L)

105.80

87.17*

Sodium (mmol/L)

144.0

142.6*

Albumin (g/L)

29.70

27.22*

Potassium (mmol/L)

6.63

7.51*

Females

 

 

Total protein (g/L)

63.08

56.44*

Cholesterol (mmol/L)

1.94

1.29*

Cholinesterase (IU/L)

382.04

310.50*

Calcium (mmol/L)

2.89

2.80*

AKP (IU/L)

338.79

227.12*

Organ weights (g; group means)

Males

 

 

Body weight at necropsy

249

206*

Brain (absolute)

1.73

1.58*

Heart (absolute)

1.11

0.92*

Kidney (left; absolute)

0.97

0.80*

Testis (left; absolute)

2.09

1.71*

Testis  (right; absolute)

2.11

1.74**

Adrenal (left; relative)

0.009

0.012*

Adrenal (right; relative)

0.008

0.011**

Females

 

 

Body weight at necropsy

157

159

Liver (relative)

4.44

4.87*

Macroscopic findings

Males

 

 

Spleen (reduced size)

0/5

2/5

Histopathology

Males

 

 

Spleen: reduction of parenchyma

0/5

5/5

Stomach

Akanthosis/Hyperkeratosis

Hyperplasia of fundic mucosa

 

 

0/5

0/5

 

4/5

5/5

Females

 

 

Stomach

Akanthosis/Hyperkeratosis

Hyperplasia of fundic mucosa

Subacute gastritis

 

1/5

0/5

0/5

 

4/5

4/5

1/5

 

 *5 % level (Dunnett-Test);**1 % level (Dunnett-Test);+5 % level (Steel-Test)

All H&E stained slides of the testes were re-examined. In addition to the routine light microscopic examination each of the 14 stages of the seminiferous epithelium was checked by careful examination of a representative number of seminiferous tubule cross sections in the respective cycle stage with the high power dry objective. Special attention was paid to possible toxic effects, e.g. degeneration of germ cells or sperm retention.

 

Groups

Control (5 males)

1000 mg/kg bw (5 males)

Focal tubular atrophy

 2/5

 3/5

 Inhibition of spermiation

 2/5

 5/5

 

The re-examination confirmed the initial examination, in which no significant toxicological findings were present at 1000 mg/kg bw in the testis.

A minimal inhibition of spermiation (stage IX and X tubules) was present occasionally in some tubules of treated animals but also in control rats. This finding was not considered as indicative for testicular toxicity, as it is a well-known spontaneous background findings in rats.

A minimal to slight focal tubular atrophy was present in control and treated rats. This finding is a frequent spontaneous finding in the rat strain used and thus not considered treatment-related.

Applicant's summary and conclusion

Conclusions:
The NOAEL of Sodium Perborate Tetrahydrate in rats after 4 weeks of oral (gavage) administration at a daily dose of 1000 mg/kg bw was slightly below 1000 mg/kg bw/d.
Executive summary:

A 4-week oral toxicity study with Sodium Perborate Tetrahydrate was performed as Limit test (one dose level of 1000 mg/kg bw/d) according to OECD Guideline 407.

The test item induced changes in body weight and food consumption, laboratory parameters and induced histopathological changes in the spleen (reduced parenchyma) and had irritating effects to the mucous membrane of the stomach.

Most of the functional changes were slight, within normal ranges and could be attributed to the histopathological changes. The target organs were identified as spleen and stomach.

A re-examination of the testes was requested by the Sponsor due to the well-known testicular toxicity of sodium borate and boric acid. The histopathological examination confirmed the original findings, i.e. there was no testicular toxicity in males.

It was concluded that the NOAEL for males or females was slightly below 1000 mg/kg bw/d.