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Toxicological information

Repeated dose toxicity: oral

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Administrative data

Endpoint:
sub-chronic toxicity: oral
Type of information:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Study period:
1978
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Comparable to guideline study with acceptable restrictions.
Cross-reference
Reason / purpose:
reference to same study

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
1978

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity in Rodents)
Deviations:
yes
Remarks:
(no ophthalmology or neurobehavioural testing; slightly limited pathology examination; some details missing from report)
GLP compliance:
no
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent

Test animals

Species:
rat
Strain:
other: Wistar-SLC
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: no data
- Age at study initiation: 5 weeks
- Weight at study initiation: no data
- Fasting period before study: no data
- Housing: "cages" (no further details given)
- Diet (e.g. ad libitum): CE-2, made by Nihon Kurea, ad libitum
- Water (e.g. ad libitum): tap water, ad libitum
- Acclimation period: 1 week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 23 +/- 2
- Humidity (%): 60 +/- 5
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): no data

Administration / exposure

Route of administration:
oral: feed
Vehicle:
unchanged (no vehicle)
Details on oral exposure:
DIET PREPARATION
- Rate of preparation of diet (frequency): no data
- Mixing appropriate amounts with (Type of food): CE-2 solid food, made by Nihon Kurea
- Storage temperature of food: no data
Analytical verification of doses or concentrations:
not specified
Details on analytical verification of doses or concentrations:
no data
Duration of treatment / exposure:
90 days
Frequency of treatment:
continuously
Doses / concentrationsopen allclose all
Remarks:
Doses / Concentrations:
0, 0.2, 1.0, and 5.0%
Basis:
nominal in diet
Remarks:
Doses / Concentrations:
0, 169, 702, 3548 mg/kg bw/day (average)
Basis:
actual ingested
No. of animals per sex per dose:
11
Control animals:
yes, concurrent no treatment
Details on study design:
Post-exposure period: none
Positive control:
none

Examinations

Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily
- Cage side observations included: no data

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: daily

BODY WEIGHT: Yes
- Time schedule for examinations: Twice weekly

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):  Evaluated twice weekly
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes

FOOD EFFICIENCY: Evaluated  twice weekly
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: No data

WATER CONSUMPTION: Weekly

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: at 90 days
- Anaesthetic used for blood collection: Yes (pentabarbital) (except blood sugar sample, which was taken from the tail vein, apparently without anaesthetic)
- Animals fasted: No data
- How many animals: all
- Parameters checked: sugar, RBC and WBC (by microcell counter), Hb (by cyanomethaemaglobin method), Haemocrit (by capillary centrifugal separation method), platelet count (by platelet counter) and differential  count (i.e. % of WBC; by ointment sample: GIEMSA dye).

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: at 90 days
- Animals fasted: No data
- How many animals: all
- Parameters checked: Alkaline phosphatase activity, ALAT and ASAT (alanine and aspartate transaminase activities), total protein, albumin/globulin ratio, total cholesterol, urea nitrogen, sodium and potassium (using a Greiner electronic selective analyser II); glucose (using enzyme method: Tokyo Zoki Kagaku reagent).

URINALYSIS: Yes, in all animals
- Time schedule for collection of urine: at 90 days
- Metabolism cages used for collection of urine: No data
- Animals fasted: No data
- Parameters checked: pH, protein, sugar, ketone bodies, occult blood (using Labstix by Nihon Emusu)

NEUROBEHAVIOURAL EXAMINATION: No
Sacrifice and pathology:
ORGANS EXAMINED AT NECROPSY (MACROSCOPIC AND MICROSCOPIC)
Macroscopic: general examination
Organ weights: brain, hypophysis, thyroid, thymus, heart, liver,  kidney, spleen, adrenal, testes or ovaries.
Microscopic: the above mentioned organs plus stomach, pancreas, small &  large intestine, lymph gland, bone marrow.
Other examinations:
none
Statistics:
STATISTICAL METHODS: Student  t test.

Results and discussion

Results of examinations

Clinical signs:
no effects observed
Mortality:
no mortality observed
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
Reduced at 1% and 5%
Food consumption and compound intake (if feeding study):
effects observed, treatment-related
Description (incidence and severity):
Reduced at 1% and 5%
Food efficiency:
effects observed, treatment-related
Description (incidence and severity):
Increased at 1% and 5%
Water consumption and compound intake (if drinking water study):
no effects observed
Ophthalmological findings:
not examined
Haematological findings:
effects observed, treatment-related
Clinical biochemistry findings:
effects observed, treatment-related
Urinalysis findings:
no effects observed
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Description (incidence and severity):
Increased relative weight of several organs in males and females at 5%
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
no effects observed
Description (incidence and severity):
No significant dose-related effects
Histopathological findings: neoplastic:
not examined
Details on results:
CLINICAL SIGNS AND MORTALITY
No animals died during the study and clinical signs were unremarkable.

BODY WEIGHT AND WEIGHT GAIN
Reduced at 1% and 5%

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
Reduced at 1% and 5% (water consumption was also reduced at these dietary levels). Food loss due to spillage was frequently reported in these groups.

FOOD EFFICIENCY
Increased at 1% and 5%

HAEMATOLOGY
Haemoglobin was significantly reduced in top dose males (15.2 g/dl (SD +-0.5) compared to 15.9 g/dl (SD +-0.4) for controls). 
Eosinophils were significantly reduced at all dose levels in males but  this was not dose related (control 1.5%; low dose 0.6%; mid dose 0.2%;  high dose 0.6%).
White blood cell count was significantly increased in high-dose females (100/mm3: control 47 (SD +- 12.2); top dose 73.2 (SD +-16.2)). This was not accompanied by any significant changes in the  differential leucocyte count. There was no increase in WBC at the low and mid dose (mean values 45.2 and 45.5 respectively).

CLINICAL CHEMISTRY
See Table 1, below.
Alkaline phosophatase (AP) activity increased from 1%; Total protein increased at 1% and 5% in males and at 5% in females. At 5%, alanine aminotransferase activity increased (ALAT), albumin/globulin ratio (AG) increased, (in females) total cholesterol reduced and (in males) potassium increased.

URINALYSIS
No treatment-related changes

ORGAN WEIGHTS
See Table 2, below.
The most significant effects on organ weights were:
Increased relative weight of thyroid, liver and kidney in males and females at 5%.
Decreased absolute weight of brain in males and females at 5%.

At 5%:
Absolute brain & heart weights were decreased in males and females. 
Absolute lung, thymus and hypophysis weights were decreased in males. 
Absolute kidney and spleen  weights were decreased in males (this effect was seen in the mid-dose males as well). 
Absolute liver, kidney and thyroid weights were increased in females.
Relative lung and heart weights were increased in males. 
Relative liver, kidney, adrenal, thyroid and hypophysis weights increased in males (adrenal and thyroid effect also seen in mid-dose males).
Relative thyroid, kidney and liver weights increased in high-dose females (the liver and kidney were also significantly affected in mid-dose females).

No biologically signficant changes in either absolute or relative organ weights were observed at the low-dose level (0.2%).

GROSS PATHOLOGY
No treatment-related effects.
Blood was observed in the stomach of 1 female in each of the mid- and high-dose groups.  There were no other remarkable changes.

HISTOPATHOLOGY: NON-NEOPLASTIC
No significant treatment-related effects.  
Slight kidney changes such as hyaline casts, calculi and increased medullary connective  tissue were observed but these were not dose related. 
In the liver slight focal necrosis was observed in 1/5 low-dose females examined; there  were no histopathological changes in mid- or high-dose groups. 
No  abnormalites were observed in any other organs including the gonads.

Effect levels

Dose descriptor:
NOAEL
Effect level:
3 548 mg/kg bw/day (actual dose received)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: Average dose. Effects observed on body weight, food consumption and food efficiency were considered to be attributable to lower food consumption as a result of lack of palatability. Effects noted on clinical chemistry were not considered adverse.

Target system / organ toxicity

Critical effects observed:
not specified

Any other information on results incl. tables

ACTUAL DOSE RECEIVED BY DOSE LEVEL BY SEX: The dose levels were based on  the results of a 14 day preliminary study in which 

groups of rats  received 0.5, 1, 3 and 10% Dobanol 45 in the diet. As only the 10% level  showed any fatalities or signs of intoxiciation the 

dose levels for the  90 day study were set at 0.2, 1 and 5% in the diet. These are equivalent  to mean intakes (in mg/kg bw/day) of: 

males 171 (101 -317), females 167 108 -271 (0.2%); 

males 759  (488 -1301), females 736 (523 -1040) (1%); 

males 3626 (2660 -5659), females 3491 (2529 -4802) (5%)


Table 1 - Clinical chemistry: Significant changes from control are as shown below:

Dose        
 AP          ALAT          T-P          A/G         T-chol          K-
Males        
(KA-U)       (K-U)          (g/dl)                    mg/dl          mEq l
Control        
13.0         37.7          5.79          1.12          39.5          4.45
0.2%        
 13.7         46.0          5.93          1.09          40.5          4.66
1%        
  15.6**        36.5          5.94*          1.14          43.0          4.66
5%        
  16.4**        71.6**         5.52*          1.25**         42.2          4.93**
Females                                                
Control       
 12.9         35.3          5.78          1.12          52.1          4.45
0.2%        
 12.4         36.7          5.83         1.12         52.8           4.36
1%        
  15.5**        35.8          5.75          1.13        52.6           4.27
5%       
  19.8**        99.4**         5.55*          1.28**         42.7**          4.38

Table 2 - Organ weights: The more significant changes (either seen in both sexes or dose related) in relative organ weights

expressed in mg/100g (thyroid  & adrenal) or g/100g are shown in the table below. 

Dose         Brain         Thyroid     Testes     Liver       Kidney      Adrenal
Males        
Control        0.57         4.55         0.91         3.14         0.61         11.6
0.2%         0.57         4.72         0.90         3.09         0.59         12.3
1%         0.61**       5.07*       0.98*        3.30         0.62         13.0*
5%         0.71**       5.53**      1.12**      4.08**     0.71*        15.4**

Females                          Ovary                        
Control      0.93        6.05         31.8         2.89         0.61         26.1
0.2%         0.92        6.52         31.0         2.98         0.64         24.8
1%         0.96        6.79         32.0         3.12*        0.65**      26.0
5%         0.96        7.60**      36.8**      3.97**       0.70**      25.9



Applicant's summary and conclusion

Conclusions:
In a reliable study, conducted using a protocol similar to OECD guideline 408, male and female rats were fed diets containing 0, 0.2%, 1% or 5% Dobanol-45 (providing average intakes of 169, 747 or 3548 mg/kg bw/day, respectively) for 90 days. Effects seen at doses higher than 0.2% included increased liver enzyme activity (alkaline phosphatase and alanine aminotransferase) and increased relative weights of a number of organs, which is attributable to the reduced body weight due to lower food consumption as a result of lack of palatability. It is considered that the increases in hepatic enzymes are not adverse as there was no associated pathology. It is therefore concluded that the NOAEL is 3548 mg/kg bw/day, the highest dose tested.