Bis(2-dimethylaminoethyl)(methyl)amine

Repeated dose toxicity: oral

Administrative data

Endpoint:

sub-chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Start of experimental phase: December 16, 2015; Termination of the in-life phase: March 16, 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity Study in Rodents)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.26 (Sub-Chronic Oral Toxicity Test: Repeated Dose 90-Day Oral Toxicity Study in Rodents)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Bis(2-dimethylaminoethyl)(methyl)amine

EC Number:

221-201-1

EC Name:

Bis(2-dimethylaminoethyl)(methyl)amine

Cas Number:

3030-47-5

Molecular formula:

C9H23N3

IUPAC Name:

(2-{[2-(dimethylamino)ethyl](methyl)amino}ethyl)dimethylamine

Test material form:

other: liquid

Details on test material:

- Name of test material (as cited in study report): Pentamethyldiethylenetriamine
- Molecular formula (if other than submission substance):
- Molecular weight (if other than submission substance):
- Smiles notation (if other than submission substance):
- InChl (if other than submission substance):
- Structural formula attached as image file (if other than submission substance): see Fig.
- Substance type:
- Physical state: liquid
- Analytical purity: >98.5% (wt)
- Impurities (identity and concentrations):
- Composition of test material, percentage of components:
- Isomers composition:
- Purity test date:
- Lot/batch No.: 890051702
- Expiration date of the lot/batch:
- Radiochemical purity (if radiolabelling):
- Specific activity (if radiolabelling):
- Locations of the label (if radiolabelling):
- Expiration date of radiochemical substance (if radiolabelling):
- Stability under test conditions:
- Storage condition of test material: At +10°C to +25°C, to be stored in original packaging in a well-ventilated place.
- Other:

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Research Models and Servies Germany GmbH, Sandhofer Weg 7, 97633 Sulzfeld, Germany
- Age at study initiation: Males: 55 days, Females: 56 days
- Weight at study initiation: Males: 275.9 g - 310.6 g, Females: 200.7 g - 236.0 g
- Fasting period before study: no
- Housing: singly
- Diet (e.g. ad libitum): conventional laboratory diet ad libitum
- Water (e.g. ad libitum): drinking water ad libitum
- Acclimation period: 7 and 8 days for the male and female main study animals, respectively.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22°C ± 3°C (maximum range)
- Humidity (%): 55% ± 15% (maximum range)
- Air changes (per hr): 15 - 20 times
- Photoperiod (hrs dark / hrs light): 12 hrs dark / 12 hrs light

IN-LIFE DATES: From: December 16, 2015 (males) or December 17, 2015 (females) To: March 15, 2015 (males) or March 16, 2015 (females)

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: tap water

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS:
The test item formulations for administration were freshly prepared daily.
The test item was diluted in the tap water to the appropriate concentrations and was
administered orally at a constant administration volume of 2 mL/kg b.w. once daily
for 90 days.

DIET PREPARATION
- Rate of preparation of diet (frequency):
- Mixing appropriate amounts with (Type of food):
- Storage temperature of food:

VEHICLE
- Justification for use and choice of vehicle (if other than water):
- Concentration in vehicle: 5, 15, 50 mg/mL
- Amount of vehicle (if gavage): 2 mL/kg b.w./day
- Lot/batch no. (if required):
- Purity:

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The samples were analysed according to the analytical method (Titration with HCl, 1 M) for the determination of the test item in liquid formulation samples validated by LPT.
The measured actual concentrations of the test item-vehicle mixtures were between 98.5% and 103.4% of the nominal concentrations, indicating correctly prepared formulations.

Duration of treatment / exposure:

90 days

Frequency of treatment:

Once daily, 7 days each week for 90 days.

Doses / concentrations

Remarks:

Doses / Concentrations:
10, 30, 100 mg/kg b.w./day
Basis:
actual ingested

No. of animals per sex per dose:

10 animals per sex per group

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: based on the results of a 28-day dose-range-finding study (LPT Study No. 32467)
- Rationale for animal assignment (if not random): The rat is a commonly used rodent species for toxicity studies.
- Rationale for selecting satellite groups:
- Post-exposure recovery period in satellite groups:
- Section schedule rationale (if not random):

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: regularly throughout the working day from 7.30 a.m. to 4.30 p.m. On Saturdays and Sundays animals were checked regularly from 8.00 a.m. to 12.00 a.m. with a final check performed at approximately 4.00 p.m.
- Cage side observations checked in table were included. Cageside observations included skin/fur, eyes, mucous membranes, respiratory and
circulatory systems, somatomotor activity and behaviour patterns. The onset, intensity and duration of any signs observed were recorded.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: once before the first exposure (to allow for within-subject comparisons) and once a week thereafter, detailed clinical observations were made in all animals; in test week 13 these observations were performed prior to any laboratory investigations. These observations were made outside the home cage in a standard arena and at the same time, each time. Signs noted included changes in skin, fur, eyes, mucous membranes, occurrence of secretions and excretions and autonomic activity (e.g. lacrimation, pilo-erection, pupil size, unusual respiratory pattern).
Changes in gait, posture and response to handling as well as the presence of clonic or tonic movements, stereotypies (e.g. excessive grooming, repetitive circling) or bizarre behaviour (e.g. self-mutilation, walking backwards) were also recorded.

BODY WEIGHT: Yes
- Time schedule for examinations: at the time of group allocation, daily from the day of commencement of treatment up to and including test week 6 for dose adjustment, thereafter weekly always on the same day of the week throughout the experimental period

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption for each animal determined and mean weekly diet consumption calculated as g food/kg body weight/week: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No

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
- Time schedule for examinations:

OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: before first dosing and at the end of the dosing period.
- Dose groups that were examined: all dose group

HAEMATOLOGY: Yes
- Time schedule for collection of blood: At the end of test week 13 (before necropsy)
- Anaesthetic used for blood collection: Yes (Isoflurane)
- Animals fasted: Yes (overnight)
- How many animals: all animals
- Parameters examined: haemoglobin content (HGB), the number of erythrocytes (RBC), leucocytes (WBC), reticulocytes (Reti) and platelets (PCT), the haematocrit value (HCT), the relative and absolute differential blood count, the thromboplastin time (TPT), the activated partial thromboplastin time (aPTT), the mean corpuscular volume (MCV), the mean corpuscular haemoglobin (MCH) and the mean corpuscular haemoglobin concentration (MCHC).

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: At the end of test week 13 (before necropsy)
- Animals fasted: Yes (overnight)
- How many animals: all animals
- Parameters examined: bilirubin (total), cholesterol (total), creatinine, glucose, protein (total), triglycerides, urea in blood, calcium, chloride, potassium, sodium, the albumin/globulin ratio, alanine aminotransferase (ALAT), alkaline phosphatase (aP), aspartate aminotransferase (ASAT), and lactate dehydrogenase (LDH), Bile Acids, Albumin, Globulin.

URINALYSIS: Yes
- Time schedule for collection of urine: At the end of test week 13 (before necropsy)
- Metabolism cages used for collection of urine: Yes
- Animals fasted: Yes (overnight)
- Parameters examined: volume, pH, specific gravity, nitrite, protein, glucose, ketones, urobilinogen, bilirubin and haemoglobin,
microscopic examination of deposits (Epithelial cells, Leucocytes, Erythrocytes, Organisms, Further constituents (i.e. sperm, casts), Crystalluria)

NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: In test week 13 (before any blood sampling for laboratory examinations)
- Dose groups that were examined: all dose groups
- Battery of functions tested: sensory activity / grip strength / motor activity:

OTHER:

Sacrifice and pathology:

GROSS PATHOLOGY: Yes, in all animals of all dose groups
HISTOPATHOLOGY: Yes, restricted to groups 1 (vehicle control) and group 4 (high dose)

Statistics:

Multiple t-test based on DUNNETT, C. W.: Body weight / Food consumption / Haematology and coagulation / Clinical chemistry / Urinalysis / Relative and absolute organ weights
Exact test of R. A. FISHER: Histology
Student’s t-test: All numerical functional tests

Results and discussion

Results of examinations

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Mortality: 100 mg Pentamethyldiethylenetriamine/kg b.w./day: One (no. 64) of 10 male high dose animals died prematurely on test day 90. A reduction in body weight and a severely reduced food intake were noted during the week before death. Clinical signs: Males: No test item-related changes in behaviour or the external appearance were noted for the male rats at any tested dose level during the routine daily observations and the detailed weekly observations. Females: At the high dose level (100 mg Pentamethyldi-ethylenetriamine/kg b.w./day) 2 of 10 animals (nos. 73 and 74) showed piloerection, ptosis, a reduced motility and breathing sounds between test days 7 and 12. As no further changes in behaviour or the external appearance were noted after test day 12 for any animal of the high dose group the observations are considered as test item-related but not as adverse.

Mortality:

mortality observed, treatment-related

Description (incidence):

Mortality: 100 mg Pentamethyldiethylenetriamine/kg b.w./day: One (no. 64) of 10 male high dose animals died prematurely on test day 90. A reduction in body weight and a severely reduced food intake were noted during the week before death. Clinical signs: Males: No test item-related changes in behaviour or the external appearance were noted for the male rats at any tested dose level during the routine daily observations and the detailed weekly observations. Females: At the high dose level (100 mg Pentamethyldi-ethylenetriamine/kg b.w./day) 2 of 10 animals (nos. 73 and 74) showed piloerection, ptosis, a reduced motility and breathing sounds between test days 7 and 12. As no further changes in behaviour or the external appearance were noted after test day 12 for any animal of the high dose group the observations are considered as test item-related but not as adverse.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

100 mg Pentamethyldiethylenetriamine/kg b.w./day: reduced body weight for the males, marginally reduced body weight for the females

Food consumption and compound intake (if feeding study):

no effects observed

Water consumption and compound intake (if drinking water study):

no effects observed

Ophthalmological findings:

no effects observed

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

no effects observed

Behaviour (functional findings):

no effects observed

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

100 mg Pentamethyldiethylenetriamine/kg b.w./day: a slight reduction in the relative and the absolute kidney weights was noted for the male rats.

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

not examined

Details on results:

CLINICAL SIGNS AND MORTALITY
Mortality:
Males:
No test item-related premature death was noted for the male animals of the control group and the low and the intermediate dose group (10 or 30 mg test item/kg b.w./day).
At the high dose level (100 mg test item/kg b.w./day) one animal (no. 64) was found dead in the morning on test day 90. A moderate reduction in body weight by 16.2% (from 486.9 g on test day 85 to 408.2 g on test day 90) and a severely reduced food intake were noted for animal no. 64 during the last test week. No other signs of clinical toxicity were noted. Due to autolytic changes, the cause of death could not be determined during the histopathological examination. However, the death is considered as test item-related.
Females:
No test item-related premature death was noted for the female animals of the control group and the treatment groups (10, 30 or 100 mg test item/kg b.w./day).
However, one animal of the high dose group (no. 73) was prematurely sacrificed on test day 9, due to its poor condition (piloerection, ptosis, a reduced motility, breathing sounds and an abdominal position were noted). The histopathological examination revealed a meningitis that was considered as spontaneous and not test item-related.

Clinical signs:Cage-side observations (daily)
Males:
No test item-related changes were noted for the male animals of the low, the intermediate and the high dose group (10, 30 or 100 mg test item/kg b.w./day).
The following observations are considered as spontaneous and not test item-related, as they were only noted for 1 animal each:
Haemorrhagic urine was noted for the male animal no. 30 of the low dose group on 7 consecutive test days from test day 83 until the end of the study on test day 90.
Breathing sounds were noted for the male animal no. 61 of the high dose group on test day 57. The breathing sounds started immediately to 5 min after administration and disappeared between 6 and 24 h after administration.
Females
No test item-related changes were noted for the female animals of the low and in-termediate dose group (10, 30 mg test item/kg b.w./day).
However, at the high dose level (100 mg test item/kg b.w./day) 2 of 10 animals showed piloerection, ptosis, reduced motility and breathing sounds on test days 7 to 9 (no. 73) or 7 to 12 (no. 74).
As the observations were only temporary (no further signs of toxicity were noted for animal no. 74 after test day 12) and no further animals of the high dose group were affected, the observations were considered as test item-related but not adverse.
Beside the above listed observations an abdominal position was additionally noted for animal no. 73 on test day 9, leading to the sacrifice of this animal due to humane reasons on the same day. 'Mortality' the poor condition of animal no. 73 were caused by a not test item-related meningitis. In case of animal no. 73 the other observations (piloerection, ptosis, reduced motility and breathing sounds) could also be related to the observed meningitis.

Detailed clinical observations (weekly)
Males:
No test item-related changes were noted for the male animals of the low, the intermediate and the high dose group (10, 30 or 100 mg test item/kg b.w./day) during the detailed clinical observations, which were performed once weekly outside the home-cage.
The not test-item-related classified observations that were noted for animal no. 30 (haemorrhagic urine) and animal no. 61 (breathing sounds) were confirmed during the process of detailed clinical observations.
Females
No test item-related changes were noted for the female animals of the low, the intermediate and the high dose group (10, 30 or 100 mg test item/kg b.w./day) during the detailed clinical observations.
The afore-mentioned clinical observations in the form of piloerection, ptosis, reduced motility and breathing sounds that were noted for the high dose female animals nos. 73 and 74 were confirmed during the process of detailed clinical observations on test day 8.

BODY WEIGHT AND WEIGHT GAIN
Males:
No test item-related influence on body weight and body weight gain was noted for
the male animals from the low and the intermediate dose group (10 or 30 mg test
item/kg b.w./day).
At the high dose level (100 mg test item/kg b.w./day) a slight but noteworthy reduction
in body weight in comparison to the control group was firstly noted on test
day 57 (6.4% below the value of the control group, not significant). Thereafter,
the difference in body weight between the control group and the high dose group
slightly increased and reached a maximum at the end of the study on test day 90
(9.3% below the value of the control group; p ≤ 0.05). Statistically significant
reductions (at p ≤ 0.05) were noted on test days 78 and 90.
Accordingly, body weight gain from start (test day 1) to the end of the study on
test day 90 was reduced for the rats of the high dose group in comparison to the
rats of the control group and the rats of the low and the intermediate dose group
(see below):

Group / Dose level Body weight gain from test day 1 to 90 (males)
Group 1 (Control) + 80.4%
Group 2 (10 mg/kg) + 78.5%
Group 3 (30 mg/kg) + 73.5%
Group 4 (100 mg/kg) + 64.5% (Group 4 (100 mg/kg) = test item-related change)

Body weight at autopsy for the male rats of the high dose group was also accordingly
reduced (453.3 g in comparison to 486.1 g for the rats of the control group).

Females:
No test item-related differences in body weight and body weight gain were noted between the female animals of the control group and the low and intermediate dose groups (10 or 30 mg test item/kg b.w./day).
A marginal and statistically not significant reduction in body weight was noted for the female animals of the high dose group (100 mg test item/kg b.w./day) after the start of dosing (approx. 3% below the value of the control group; mostly due to animal no. 74 which also showed changes in behaviour and appearance on several test days between the first and second test week.
The marginal reduction in body weight that was noted for the female animals of the high dose group after the start of dosing showed no noteworthy effect on the value of body weight gain for the whole study period (see below).

Group / Dose level Body weight gain from test day 1 to 90 (females)
Group 2 (10 mg/kg) + 44.3%
Group 2 (10 mg/kg) + 42.7%
Group 3 (30 mg/kg) + 38.7%
Group 4 (100 mg/kg) + 39.0%


Body weight at autopsy also revealed no noteworthy differences between the fe-male animals of the control group and the treatment groups.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)

FOOD EFFICIENCY

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study)

OPHTHALMOSCOPIC EXAMINATION

HAEMATOLOGY

CLINICAL CHEMISTRY

URINALYSIS

NEUROBEHAVIOUR

ORGAN WEIGHTS: No test item-related differences were noted between the relative and the absolute organ weights of the male and female animals of the control group and the male and female animals of the low and intermediate dose groups (10 or 30 mg test item/kg b.w./day).A slight reduction in the relative and absolute weight of the kidneys were noted for the male animals of the high dose group (100 mg test item/kg b.w./day) (statistically significant for the right kidney). As no reduction of the kidney weights was noted for the female animals, the reduction noted for the kidney weights of the male rats is considered to be a secondary effect of the reduced body weight of the male rats of the high dose group.
Group /
Dose level Kidney weights of male animals
(% change in comparison to control)
Relative Absolute
left right left right
Group 2
(10 mg/kg) - 3.2 - 4.0 - 5.0 - 5.6
Group 3
(30 mg/kg) - 6.3 - 6.7 - 8.3 - 8.7
Group 4
(100 mg/kg) - 7.7 - 8.2 * - 14.2 - 14.6 *
*/**: p ≤ 0.05/0.01, Dunnett test or Student's t-test.

No test item-related differences between the control group and the treatment groups (10, 30 or 100 mg test item/kg b.w./day) were noted between the relative and the absolute organ weights of the female animals.

GROSS PATHOLOGY

HISTOPATHOLOGY: NON-NEOPLASTIC

HISTOPATHOLOGY: NEOPLASTIC (if applicable)

HISTORICAL CONTROL DATA (if applicable)

OTHER FINDINGS

Effect levels

Dose descriptor:

NOAEL

Effect level:

30 other: mg Pentamethyldiethylenetriamine/kg b.w./day

Sex:

male/female

Basis for effect level:

other: see 'Remark'

Target system / organ toxicity

Critical effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

Under the present test conditions the No-Observed-Adverse-Effect-Level (NOAEL) was 30 mg Pentamethyldiethylenetriamine/kg b.w./day for the male and female animals.

Executive summary:

The aim of this study was to obtain information on the toxicity of Pentamethyldiethylenetriamine administered daily by oral administration at doses of 10, 30 or 100 mg/kg b.w./day to CD® rats for 90 test days. At 100 mg Pentamethyldiethylenetriamine/kg b.w./day one of 10 male animals died prematurely on test day 90. No test item-related premature death was noted for the female animals. A reduction in body weight was noted for the male and female animals of the high dose group 100 mg Pentamethyldiethylenetriamine/kg b.w./day. The kidney weights of the male animals of the high dose group (100 mg Pentamethyldiethylenetriamine/ kg b.w./day were reduced. No test item-related effect was noted on the organ weights of the female animals. No test item-related changes in behavior or the external appearance were noted for the male animals. For the female animals changes in the form of piloerection, ptosis, a reduced motility and breathing sounds were noted for 2 of 10 animals. The observations disappeared after a few days and are not considered as adverse. No test item-related influence was noted on the food and drinking water consumption, the haematological and biochemical parameters, the urinary status, the eyes or optic region and the auditory acuity at any of the dose levels. No test item related changes were noted at macroscopic and histopathological inspection. Under the present test conditions the No-Observed-Adverse-Effect-Level (NOAEL) was 30 mg Pentamethyldiethylenetriamine/kg b.w./day for the male and female animals.