Registration Dossier

Administrative data

Endpoint:
sub-chronic toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
March - July 1983
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Comparable to guideline study under GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1983
Report Date:
1983

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 nerobehavioral tests were made, no purity of the test item was reported, 4-week recovery period in the control and high-dose group
GLP compliance:
yes
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material : BMDBM
- Physical state: solid

Test animals

Species:
rat
Strain:
other: Füllinsdorf Albino-SPF
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Füllinsdorf
- Age at study initiation: 6-8 weeks
- Weight at study initiation: 158-190g (males), 130-147g (females)
- Housing:2 animals per cage
- Diet (e.g. ad libitum): NAFAG No. 850, restricted (feeding study)
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24
- Humidity (%): 45-65
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 1983-03-08 To: 1983-07-07

Administration / exposure

Route of administration:
oral: feed
Vehicle:
unchanged (no vehicle)
Details on oral exposure:
DIET PREPARATION
- Rate of preparation of diet (frequency): The test article was sifted to remove clots and mixed with the rat diet. The mixtures were freshly prepared each week (2.5 kg diet + test article for each male dose group; 2 kg diet + test article for each female dose group).
- Mixing appropriate amounts with (Type of food): NAFAG No. 850 (pulverized)
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Samples of mixtures for analysis were taken during week 2 and week 13.
Duration of treatment / exposure:
91-94 days
Half the animals of the control and of the high-dose group were observed for further 30 days without treatment.
Frequency of treatment:
daily
Doses / concentrations
Remarks:
Doses / Concentrations:
0, 200, 450, and 1000 mg/kg bw/day
Basis:
nominal in diet
No. of animals per sex per dose:
12 rats per sex per dose group
Control animals:
yes, plain diet
Details on study design:
- Rationale for animal assignment: random table
- Post-exposure recovery period: 30 days
Positive control:
no positive control substance was used

Examinations

Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: continuously

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: weekly

BODY WEIGHT: Yes
- Time schedule for examinations: weekly

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes

FOOD EFFICIENCY:
- 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

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No

OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: at week 13
- Dose groups that were examined: only high-dose group (1000 mg/kg bw/day)

HAEMATOLOGY: Yes
- Time schedule for collection of blood: during weeks 2, 6, and 14
- Anaesthetic used for blood collection: Yes (N2O)
- Animals fasted: No data
- How many animals: all
- Parameters checked in table 1 were examined.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: during weeks 2, 6, and 14
- Animals fasted: No data
- How many animals: all
- Parameters checked in table 1 were examined.

URINALYSIS: Yes
- Time schedule for collection of urine: during week 5 and 13
- Metabolism cages used for collection of urine: Yes
- Animals fasted: Yes
- Parameters checked in table 1 were examined.

NEUROBEHAVIOURAL EXAMINATION: No
Sacrifice and pathology:
GROSS PATHOLOGY: Yes (see table 2)
HISTOPATHOLOGY: Yes (see table 2)
Statistics:
Results of haematology and blood chemistry:
Dunn test (Technometrics 1964, 6: 241-52):Multiple comparisons, control versus all treated groups. Error rate = 0.1.

Body weights:
Growth rate (Rao, Biometrics 1958, 14: 1-17)
Adjusted organ weights (Trieb et al., Toxicol. Appl. Pharmacol. 1976, 35: 531-42)
Jonckheere test (Biometrika 1954, 41: 133-45)
U-test (Siegel, Monoparametric statistics 1956)

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:
no effects observed
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
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Histopathological findings: neoplastic:
no effects observed
Details on results:
CLINICAL SIGNS AND MORTALITY
Treatment-related deaths did not occur. Two female rats (450 mg/kg/day; 1000 mg/kg/day) died as a result of anaesthesia and taking of blood samples.
Clinical signs were loss of hair, excitation, and crusted eye. The symptoms were distributed among the test groups as summarised in table 3. With one exception all symptoms had a slight intensity. These symptoms are normally found in animals used fort his study.
They were not considered to be treatment-related.

BODY WEIGHT AND WEIGHT GAIN
The weight development of all groups took a normal course throughout the study with the exception of the male group treated with 450 mg/kg/day. In this group, 4 rats did not receive their diet as a result of a blockage of the feed containers for some days. In this study, there was no influence of the test article butyl methoxydibenzoylmethane (BMDBM) on the body weight development.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
The feed consumption of males and females treated with 200 mg/kg bw/day was slightly higher than that of the control animals whereas males and females treated with 450 and 1000 mg/kg bw/day consumed less feed than control animals. These observations can be correlated with the body weight development.
The compound intakes are listed in table 4 and were all slightly higher than the intended dose.

OPHTHALMOSCOPIC EXAMINATION
No findings were observed in eyes of control rats and rats treated with 1000 mg/kg bw/day.

HAEMATOLOGY
All mean values of haematologic parameters were within the normal limits for rats in this laboratory at weeks 2 and 6, but at week 14, the mean RBC and Hb values of females treated with 1000 mg/kg bw/day nearly lay at the lower limit and were clearly lower than the mean RBC and Hb values of the female control group. The trend refering to the RBC decrease in the female group treated with 1000 mg/kg bw/day already occurred at week 6.
The RBC decrease in females treated with 1000 mg/kg bw/day was considered to be related to treatment.

CLINICAL CHEMISTRY
The mean values of parameters of clinical chemistry listed in table 6 minimally laid outside of the physiological range for rats in this laboratory. These findings were considered to be treatment-related but not systematizable.

A few particular values clearly juted out from the physiological range (AST in 1 animal of the control group, GLDH in 1 animal of the low-dose and in 2 animals of the high-dose group). These observations were not considered to be of toxicological importance.

URINALYSIS
Urinalysis results were similar in treated and control groups.

ORGAN WEIGHTS
With the exception of liver weights, all organ weights laid within the physiological range for rats in this laboratory. Mean relative liver weights of male rats treated with 1000 mg/kg bw/day as well mean absolute and mean relative liver weights of female rats treated with 200 mg/kg bw/day approached the upper limit of normal (table 7). Mean absolute and mean relative liver weights of female rats treated with 450 and 1000 mg/kg bw/day laid above of the physiological range.
These observations can be correlated with the slight increase in size of hepatic parenchyma cells in female rats treated with 1000 mg/kg bw/day (the lower dose groups were not examined).
The described increase of liver weights were considered to be related to treatment.
After a treatment-free period of 4 weeks, liver weights of male and female rats formerly treated with 1000 mg/kg bw/day were comparable with liver weights of control rats.

GROSS PATHOLOGY
Necropsy findings were sporadic and consisted of bladder concrement and renal and ovarian cysts.
These observations were accidental findings which were not considered to be related to treatment.

HISTOPATHOLOGY:
The histopathological changes are summarized in table 8.
With the exception of the slight increase in size of hepatic parenchyma cells, all other changes were not considered to be of toxicological importance. The incidence, degree, and group distribution of these changes did not show any effect of the treatment with BMDBM on a cellular structure of the examined organs and tissues.


The oral administration of BMDBM when given for 13 weeks caused a slight reduction of red blood cells in female rats treated with 1000 mg/kg/day. The quantity of reticulocytes was normal and the bone marrow was unchanged. The reason for the erythrocytes reduction was not detected.
The absolute and relative liver weights were higher in male rats treated with 1000 mg/kg/day and in all female dose groups than those in the control groups. In addition, a hepatocellular hypertrophy appeared in female rats treated with 1000 mg/kg/day (the lower dose groups were not examined). These findings were signs of an intensification of hepatic function which was interpreted as a process of adaptation because the liver weights of high dosed males and females were normalized after a treatment-free period of 4 weeks.
In all probability, the petty shifts of concentration of plasma proteins have connexion with the process of adaption.

Effect levels

open allclose all
Dose descriptor:
NOAEL
Effect level:
450 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male/female
Dose descriptor:
LOAEL
Effect level:
1 000 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: Significant incresed liver weights and reduced Hb and RBC in the females of the 1000 mg/kd bw/day dose group.

Target system / organ toxicity

Critical effects observed:
not specified

Any other information on results incl. tables

Table 3: Clinical observations made during the oral administration of butyl methoxydibenzoylmethane (BMDBM) to rats over 90 days.

Symptom

Control

BMDBM [mg/kg bw/day]

200

450

1000

Loss of hair

1F

2F

-

2F

Exitation

-

1F

2M

1M

Crusted eye

-

-

1F

1M

F: female, M. male

 

Table 4: Compound intake during the oral administration of butyl methoxydibenzoylmethane (BMDBM) to rats over 90 days.

Intended dose
[mg/kg bw/day]

Mean compound intake [mg/kg bw/day]

Males

Females

0

0.00

0.00

200

204.27

202.64

450

459.34

247.73

1000

1019.32

1012.75

 

Table 5:Selected haematology findingsmade during the oral administration of butyl methoxydibenzoylmethane (BMDBM) to female rats over 90 days.

 

Control

BMDBM [mg/kg bw/day]

200

450

1000

Red blood cell count (Mio./µL)

Week 2

7.55±0.30

7.29±0.28

7.38±0.39

7.38±0.34

Week 6

8.28±0.16

8.03±0.34

7.96±0.32

7.88±0.17

Week 14

8.38±0.10

8.29±0.29

8.15±0.30

7.77±0.20

Hemoglobin (g/dL)

Week 2

15.7±0.6

15.1±0.8

15.2±0.9

15.0±0.6

Week 6

16.5±0.4

15.7±0.5

15.7±0.3

15.6±0.5

Week 14

16.0±0.2

15.5±0.6

15.4±0.7

14.3±0.2

 

Table 6: Selected clinical chemistry findingsmade during the oral administration of butyl methoxydibenzoylmethane (BMDBM) to rats over 90 days

Test group [mg/kg bw/day]

Sex

Parameter

Week

Change

1000

Males

Potassium

6

Increased

1000

Males

Albumin [%]

6

Increased

1000

Males

Albumin [g/L]

6

Increased

1000

Males

Albumin/globulin

6

Increased

1000

Females

Albumin [%]

6

Increased

450, 1000

Females

alpha-Globulin 3 [%]

6

Decreased

450, 1000

Females

alpha-Globulin 3 [g/L]

6

Decreased

1000

Females

Albumin/globulin

6

Increased

1000

Females

Albumin [%]

14

Increased

200, 450, 1000

Females

beta-Globulin 3 [%]

14

Decreased

200, 450, 1000

Females

beta-Globulin 3 [g/L]

14

Decreased

1000

Females

Albumin/globulin

14

Increased

 

Table 7: Absolute liver and liver-to-brain ratios of rats fed butyl methoxydibenzoylmethane (BMDBM) over 90 days

 

Control

BMDBM [mg/kg bw/day]

200

450

1000

Males

Absolute [g]

15.557±2.153

16.198±2.517

16.836±1.820

17.263±2.363

Relative [g/ 100g bw]

6.04±0.73

6.40±0.71

6.77±0.50

7.46±0.87 *

Males (4 weeks recovery)

Relative [g/ 100g bw]

6.17±0.54

 

 

6.36±0.43

Females

Absolute [g]

8.517±0.847

10.312±1.203

10.900±0.723

11.101±2.107

Relative [g/ 100g bw]

5.42±0.45

6.60±0.63##

7.26±0.47 **

8.59±0.74 **

Females (4 weeks recovery)

Relative [g/ 100g bw]

5.73±0.34

 

 

6.25±0.60

* P<0.05 (Jonckheere test)

** P<0.01 (Jonckheere test)

##P<0.01 (U-test)

 

Table 8: Number of animals with gross, non-neoplastic, or neoplastic lesions at end of dosing period.

SEX

males

females

DAILY DOSE
(mg/kg bw/day)

0

1000

0

1000

NUMBER OF ANIMALS EXAMINED

6

6

6

6

Heart

Non-neoplastic lesion:

 

 

 

 

Myocardial necrosis, slight

1

 

 

 

Multifocal lympho-histiocytic infiltration

of the interstice, minimal to slight

5

5

5

5

Small accumulation of inflammatory cells within of the ventricle, minimal

1

 

1

 

Small focus of cartilage, minimal

1

2

 

 

Neoplastic lesion:

 

 

 

 

Lung

Non-neoplastic lesion:

 

 

 

 

Small atelectatic region, minimal

1

 

 

1

Small focus of inflammatory cells in the interstice, minimal

 

 

1

1

Diffuse infiltration of inflammatory cells in the connective tissue, minimal

 

 

 

1

Trachea

Non-neoplastic lesion:

 

 

 

 

Desquamation of epithelial cells, minimal

1

 

 

 

Liver

Non-neoplastic lesion:

 

 

 

 

Lympho-histiocytic infiltration of portal tracts with altered bile ducts, minimal to moderate

3

6

6

6

Multifocal infiltration of the parenchyma by mainly lymphocytes and histiocytes, minimal to moderate

6

6

4

6

Focal necroses in the parenchyma, minimal to moderate

1

3

1

2

Increased fat content, minimal to slight

2

 

 

 

Slight increase in size of hepatic parenchyma cells

 

 

 

6

Pancreas

Non-neoplastic lesion:

 

 

 

 

Area with increase of connective tissue and loose infiltration by inflammatory cells and destruction

of the exocrine parenchyma, minimal to moderate

1

2

 

1

Perivascular accumulation of lymphocytes, minimal

 

 

3

 

Kidney

Non-neoplastic lesion:

 

 

 

 

Subcapsular lympho-histiocytic infiltration, minimal

 

1

 

 

Perivascular lympho-histiocytic infiltration, minimal

1

1

 

3

Lympho-histiocytic infiltration with necrosis of epithelium of renal tubules, minimal

1

2

1

 

Nephrocalcinosis, minimal

 

 

3

3

Thyroid

Non-neoplastic lesion:

 

 

 

 

Desquamation of epithelial cells, minimal to moderate

6

4

4

4

Thyroid of recovery animals

Non-neoplastic lesion:

 

 

 

 

Desquamation of epithelial cells, minimal to slight

2

5

5

3

Adrenal gland

Non-neoplastic lesion:

 

 

 

 

Focal infiltration by mainly lymphocytes, minimal

1

2

1

3

Testis

Non-neoplastic lesion:

 

 

 

 

Damage of the germinal epithelium, moderate to severe

 

1

 

 

Bone

Non-neoplastic lesion:

 

 

 

 

Epiphyseal plate with an irregula region, minimal

 

 

1

1

 

Applicant's summary and conclusion

Conclusions:
Under the conditions of this study, the NOAEL was considered to be 450 mg/kg/day. A significant increase in absolute and relative liver weight was observed in female rats at 450 and 1000 mg/kg bw/day and in male rats at 1000 mg/kg bw/day. Furthermore, a decrease in RBC and Hb was observed in female animals at 1000 mg/kg bw/day.
Executive summary:

The UV-A filter butyl methoxydibenzoylmethane (BMDBM) was administered as feed admix during 13 weeks. Four test groups each consisting of 12 rats per sex were formed. The animals received 0, 200, 450, and 1000 mg active ingredient per kg body weight per day. Mortality, general symptoms, and body weights were recorded. Haematology and clinical chemistry determinations were performed. All rats were autopsied. Organs and tissues of the control rats and rats treated with 1000 mg/kg bw/day were microscopically examined.

Deaths related to treatment did not occur throughout the test period. Two female rats died as a result of anaesthesia. Treatment-related clinical symptoms were not observed. The treatment with BMDBM did not have an effect on the weight development and feed consumption. The number of red blood cells was decreased in female rats treated with 1000 mg/kg bw/day. The results of the urinalysis were normal. No findings were observed in eyes of control rats and rats treated with 1000 mg/kg bw/day. No treatment-related necropsy findings were seen. The liver weights of male rats treated with 1000 mg/kg bw/day and of females treated with 200, 450, and 1000 mg/kg bw/day were higher than those of the control groups. The liver weight increase in the animals treated with 200 mg/kg bw/day could be attributed to their higher body weight compared to the control animals, but the effect in the higher dose groups must be considered as related to treatment. After a treatment-free period of 4 weeks, the high dosed male and female rats had a normal liver weight. With the exception of hepatic parenchyma cells which became hypertrophic in females treated with 1000 mg/kg bw/day, no histopathological changes were considered to be related to treatment.

Under the conditions of this study, the maximum oral dose level producing no toxic effect (NOAEL) was considered to be 450 mg/kg/day. The increase of liver weights as well the increase of hepatic parenchyma cells were interpreted as a process of liver adaption to treatment.