Bromo(hexahydro-2H-azepin-2-onato-N)magnesium

Repeated dose toxicity: oral

Administrative data

Endpoint:

sub-chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

03/2008 to 09/2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Bromo(hexahydro-2H-azepin-2-onato-N)magnesium

EC Number:

241-158-2

EC Name:

Bromo(hexahydro-2H-azepin-2-onato-N)magnesium

Cas Number:

17091-31-5

Molecular formula:

C6H10BrMgNO

IUPAC Name:

magnesium(2+) ion 2-oxoazepan-1-ide bromide

additive 1

Reference substance name:

ε-caprolactam

EC Number:

203-313-2

EC Name:

ε-caprolactam

Cas Number:

105-60-2

Molecular formula:

C6H11NO

IUPAC Name:

azepan-2-one

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 07072601
- Expiration date of the lot/batch: 26.07.2008

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature 20 ± 5 °C

Test animals

Species:

rat

Strain:

Wistar

Details on species / strain selection:

Wistar-Unilever

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Winkelmann GmbH, Gartenstraße 27, 33178 Borchen, Germany
- Age at study initiation: 5- 8 weeks
- Weight at study initiation: 141-166 g (females), 163-185 g (males)
- Diet (e.g. ad libitum): Maintenance diet rat/mouse, pellets, No. 1324 (Altromin GmbH & Co. KG, 32791 Lage), ad Jib.
- Water (e.g. ad libitum): Autoclaved community tap water, ad lib.
- Acclimation period: 8 days (males), 9 days (females)

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3°C
- Humidity (%): 30-70%
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The required amount of Bromo(hexahydro-2H -azepin-2-onato-N)magnesium is weighed into an appropriate vial on an analysis scale. Water is added up to the required volume. Stirring for 5 minutes. The test solutions were intended for an application volume of 4 ml per kg body weight. All preparation protocols for the test solutions were stored with the raw data.

Duration of treatment / exposure:

28 days

Frequency of treatment:

daily

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

63 mg/kg bw/day (nominal)

Doses / concentrations 2

Dose / conc.:

250 mg/kg bw/day (nominal)

Doses / concentrations 3

Dose / conc.:

1 000 mg/kg bw/day (nominal)

No. of animals per sex per dose:

5

Control animals:

yes, concurrent vehicle

Positive control:

no

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Once a week

BODY WEIGHT: Yes
- Time schedule for examinations: Once a week

FOOD EFFICIENCY:
- Group food consumption: Once weekly

NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: Once before application and once during the last exposure week
- Battery of functions tested: grip strength

Sacrifice and pathology:

HISTOPATHOLOGY: Yes

Gross lesions
Oesophagus
Trachea and thyroid
Stomach
Thymus
Liver
Spleen
Duodenum
Jejunum
Ileum (with peyer's p patches)
Cecum
Colon
Rectum
Lymph nodes (intestinal p area)
Kidney
Adrenals
Urinary bladder
Testes/ovary
Epididymides
Prostata/uterus
Heart
Lungs
Peripheral nerve
Bone marrow
Sternum
Spinal cord
Whole brain
Cerebrum
Cerebellum
Pons

Results and discussion

Results of examinations

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Observation of apathetic behaviour amongst male animals of the high dose group in the last two days of the in-life phase.
Elevated water consumption for both sexes, especially in the high dose group.
Increased weight gain in the high dose groups.
Increased liver and kidney weights in the male high dose group and increased liver weight in the female high dose group.

Mortality:

no mortality observed

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Female animals in the high dose group showed increased weight gain in comparison to the vehicle group.

Food efficiency:

not examined

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

Analysis of haematology and serum biochemistry showed normal results in most instances.

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

Mild effects were observed mainly in the high dose groups.

In the male animals, significant but weak changes in the data of the high dose group
emphasised a lowered creatinine and glutamic-oxaloacetic transaminase (GOT) level, as
well as an elevated level in chloride and cholesterol and a higher mean corpuscular volume
(MCV). In the medium dose group, chloride levels and MCV were also elevated. The low
dose group showed an elevated cholesterol level, as well. These parameters can be
indicators for an alteration of kidney function.

In the female high dose animals, creatinine levels were also lowered, whereas globulin,
chloride, alanine aminotransferase (GPT), and alkaline phosphatase levels were elevated.
Globulin levels were also elevated in the medium dose animals. These parameters can be
indicators for an alteration in liver function.

Although some significant changes were observed, none of the observed average data
points were overall extremely out of range for rats of this strain and age. Other biochemical
parameters and the blood cell counts showed no significant differences among the groups.

Urinalysis findings:

not examined

Behaviour (functional findings):

no effects observed

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

Increased weight gain in the high dose groups.
Increased liver and kidney weights in the male high dose group and increased liver weight in the female high dose group.

Gross pathological findings:

no effects observed

Neuropathological 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 (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

behaviour (functional findings)

body weight and weight gain

clinical biochemistry

clinical signs

gross pathology

haematology

histopathology: neoplastic

histopathology: non-neoplastic

mortality

neuropathology

organ weights and organ / body weight ratios

water consumption and compound intake

Target system / organ toxicity

Critical effects observed:

no

Applicant's summary and conclusion

Conclusions:

Detailed clinical signs, food consumption, motor activity, and reactivity to sensory stimuli
showed no abnormalities. On the last two days of the in-life phase, the male high dose
animals appeared apathetic.

Especially the female animals of the high dose group showed a significantly increased weight
gain in comparison to the vehicle groups. This effect was less pronounced in the other dose
groups. Water consumption was elevated in the test item groups of both sexes, particularly in
the high dose groups.

Of the hematology and serum biochemistry parameters, none were overall extremely out of
range for rats of this strain and age. In comparison to the vehicle groups, the animals of the
male high dose group showed lowered creatinine and GOT levels and elevated chloride and
cholesterol levels, as well as a higher mean corpuscular volume. The animals of the female
high dose group showed lowered creatinine and elevated globulin, chloride, GPT, and
alkaline phosphatase levels.

At necropsy, no treatment related changes were noted. The most noticable differences in
organ weights were an increased liver and kidney weight in the male high dose group and an
increased liver weight in the female high dose group.

Microscopically, there were no pathologic findings that are considered to be related to the
treatment with the test item.

The blood parameters, organ weights, and water consumption may point to an alteration of
liver and kidney function if the test item is administered at a high dose and over a longer
period of time, but under the conditions of this study, the repeated oral administration of the
test item Bromo(hexahydro-2H-azepin-2-onato-N)magnesium to Wistar-Unilever rats at dose
levels of 1.000, 250, and 63 mg/kg bodyweight for a treatment period of 28 days did not
produce any pathological evidence of a local or systemic toxicity of the test item.

Executive summary:

No evidence of a local or systemic toxicity of the test item was observed at levels of 1.000, 250, and 63 mg/kg bodyweight for a treatment period of 28 days.

The NOAEL was set to 1.000 mg/kg bw/day.