Propanamide, 3-amino-2,2-dimethyl-

Repeated dose toxicity: oral

Administrative data

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP - Guideline Study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2005

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)

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Remarks:

ARC Seibersdorf research GmbH

Limit test:

no

Test material

Test material information

Constituent 1

Details on test material:

- Physical state: white solid
- Analytical purity: 98.4%
- Lot/batch No.: 0424
- Storage condition of test material: in refrigerator, storage in the dark but may be used under light.

Test animals

Species:

rat

Strain:

Fischer 344

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Winkelman GmbH, Borchen, Germany
- Age at study initiation: 6 weeks
- Mean weight at study initiation: males: 170.1 g, females: 127.2 g
- Fasting period before study: no
- Housing: group caging (2 or 3 animals of one group and one sex per cage), the first 3 animals of a group and the second 2 animals of a group are housed together
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): average of 21.9
- Humidity (%): avarage of 41.1
- Air changes (per hr): 12
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS:
Preparations of the test substance were made freshly every day shortly before the administration to the animals. Appropriate preparations were made to allow a uniform dose volume for all groups.

Analytical verification of doses or concentrations:

yes

Duration of treatment / exposure:

28 days

Frequency of treatment:

daily, 7 days/week

Doses / concentrations

Remarks:

Doses / Concentrations:
100, 316, 1000 mg/kg bw/day
Basis:
actual ingested

No. of animals per sex per dose:

5

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: The doses chosen are derived from and based on the results of the dose range finding study. Groups of 5 male and 5 female rats each were given 100 or 316 or 1000 mg test substance in 10 mL water orally once a day for 7 consecutive days. All animals survived until the terminal sacrifice. There were no treatment related observations in life; the body weights and the feed consumption were not notably affected. All animals were found to be grossly normal at post mortem examination. The high dose in the main study shall induce a clear toxicity, but no or at most isolated mortality. A dose of 1000 mg per kg b.w. will not be exceeded as high dose and is thus chosen as high dose. The low dose shall induce no toxic effect. It was set at 10 % of the high dose. The mid dose is interpolated geometrically.
- Rationale for selecting satellite groups: to observe the reversibility or persistence of the test substance induced lesions
- Post-exposure recovery period in satellite groups: 15 days

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: days: -1, 7, 14, 21, 27: all animals of all groups and days 35 and 41: all animals of the satellite groups

BODY WEIGHT: Yes
- Time schedule for examinations: day 1 to 28: once a week, all animals; days 35 and 42: satellite groups

FOOD CONSUMPTION: determined per cage in weekly intervals in all animals

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: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: day 29 from all animals except satellite groups; satellite groups: all animals on day 43
- Anaesthetic used for blood collection: Yes: slight ether anaesthesia
- Animals fasted: Yes
- How many animals: all

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: same as haematology
- Animals fasted: Yes
- How many animals: same as haematology

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: on day 27 and day 41
- Dose groups that were examined: all animals on day 27, on day 41 all animals of satallite groups
- Battery of functions tested: sensory activity / grip strength / motor activity

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes

Statistics:

Analysis of variance: used for all data with means and standard deviations determined
Scheffé test: used for comparison of more than two groups
t-test: all data with means and standard deviations determined, for comparison of two groups only
H-test of Kruskal and Wallis followed by the test of Nemenyi: used for counted events with scoring or in cases where the requirements for the analysis of variance were not fulfilled
χ2-test: used for counted events
Fisher's exact test: used for counted events, if the χ2-test was not applicable

Results and discussion

Results of examinations

Details on results:

CLINICAL SIGNS AND MORTALITY: There was no test substance related mortality, all animals survived until their scheduled sacrifice. Signs of reduced well-being were noted shortly after dosing in the high dosed animals. Otherwise no test substance related effects were noted.

BODY WEIGHT AND WEIGHT GAIN: The body weight gain of the high dosed recovery group males was significantly reduced in the first two weeks of dosing. No test substance related effects were noted in the body weights themselves or in the feed consumption.

HAEMATOLOGY & CLINICAL CHEMISTRY:
Platelet count (males) - high dose - significant increase
Lymphocytes (females) - high dose, after recovery - significant decrease
Alkaline phosphatase (females) - high dose, after recovery - significant increase
The changes in platelet count may be due to the test substance, while both the differences in lymphocyte count and in alkaline phosphatase are of equivocal relevance.

NEUROBEHAVIOUR: There were no differences between a dosed group and the corresponding control group noted at the functional observations or at the determinations of the grip strength. All observations made are in accordance with a normal behavioural pattern of the strain of rats used.

ORGAN WEIGHTS: There were no significant differences in the organ weights.

GROSS PATHOLOGY & HISTOPATHOLOGY: There were no significant differences nor any test substance related alterations noted.

OTHER FINDINGS: Satellite groups: There were a few scattered significant differences noted at the end of the satellite period. None of them can be attributed to the test substance, as to the lack of corresponding alterations at the end of the dosing period. None of the test substance related effects, noted during or at the end of the dosing period, persisted until the end of the recovery period.

Effect levels

1

Dose descriptor:

NOEL

Effect level:

316 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: no effects observed

2

Dose descriptor:

NOAEL

Effect level:

>= 1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: Marginally decreased body weight gain and isolated haematological alterations in the high dose treatment are considered as not adverse.

Target system / organ toxicity

Critical effects observed:

not specified