4-Piperidinone, 2,6-diethyl-2,3,6-trimethyl-1-(1-phenylethoxy)-

Repeated dose toxicity: oral

Administrative data

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2007 / 2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Performed accoring to OECD and EEC-guidelines under GLP

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)

Test material

Test material information

Constituent 1

Details on test material:

Identification: TKA 40270 (CGPS 345)

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

Animals: Rat, HanRcc: WIST(SPF)
Rationale: Recognized by international guidelines as a recommended rodent test system.
Breeder: RCC Ltd
Laboratory Animal Services
Wölferstrasse 4
4414 Füllinsdorf / Switzerland

Number of Animals: Group 1: 10 males and 10 females
Group 2: 5 males and 5 females
Group 3: 5 males and 5 females
Group 4: 10 males and 10 females
Reserve animals:
Group 10: 1 male and 1 female
These were removed from the study during the
acclimatization period.
Age (at Delivery): Ca. 7 weeks
Body Weight Range
(at Acclimatization): Males: 178 to 206 g (mean 196 g)
Females: 130 to 148 g (mean 140 g)
Identification: Cage card and individual animal number (ear tattoo).
Acclimatization: Under test conditions after health examination. Only
animals without any visible signs of illness were
used.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

TKA 40270 (CGPS 345) was administered daily by oral gavage to SPF-bred Wistar rats of both sexes at dose levels of 60, 200 and 600 mg/kg body
weight/day for a period of 28 days. A control group was treated similarly with the vehicle, corn oil, only. A
dose volume of 5 mL/kg was administered.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Several application formulations were prepared and representative analytical samples were
collected and dispatched to the analytical laboratories internally. The test item concentrations
were determined by HPLC coupled to an UV detector and quantified with the area under the
peak.

Duration of treatment / exposure:

28 days

Frequency of treatment:

Daily

Doses / concentrations

Remarks:

Doses / Concentrations:
60, 200 and 600 mg/kg body weight/day for a period of 28 days.
Basis:
other: nominal in corn oil

No. of animals per sex per dose:

Number of Animals:
Group 1 (control): 10 males and 10 females
Group 2 (60 mg/kg/day): 5 males and 5 females
Group 3 (200 mg/kg/day): 5 males and 5 females
Group 4 (600 mg/kg/day): 10 males and 10 females

Control animals:

yes, concurrent vehicle

Details on study design:

The test substance was administered daily by oral gavage to SPF-bred Wistar rats of both sexes at
dose levels of 60, 200 and 600 mg/kg body weight/day for a period of 28 days.
A control group was treated similarly with the vehicle, corn oil, only.
A dose volume of 5 mL/kg was administered.
The groups comprised 5 animals per sex which were sacrificed after 28 days of treatment.
Additional 5 rats per sex and group were used at 0 and 600 mg/kg. These animals were treated
for 28 days and then allowed a 14-day treatment-free recovery period after which they were
sacrificed.
Clinical signs, outside cage observation, food consumption and body weights were recorded
periodically during pretest, the treatment and recovery periods. Functional observational battery,
locomotor activity and grip strength were performed during week 4.
At the end of the dosing and the treatment-free recovery period, blood samples were withdrawn
for hematology and plasma chemistry analyses. Urine samples were collected for urinalyses. All
animals were killed, necropsied and examined post mortem. Histological examinations were
performed on organs and tissues from all control and high dose animals, and all gross lesions
from all animals.
From the animals of the low and middle dose groups, the livers, spleens and thyroid glands were
examined to establish a no-effect level.

Positive control:

No

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Daily
- Cage side observations checked in table [No.?] were included.


DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: day 4 to 28


BODY WEIGHT: Yes
- Time schedule for examinations: Before treatment, day 4, and 15 to 28


FOOD CONSUMPTION AND COMPOUND INTAKE :
- 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:
- 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: Yes


WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): Yes
- Time schedule for examinations: day 4 to 8


OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: 28 day
- Dose groups that were examined: No test item-related changes of toxicological relevance were noted at any dose leve



HAEMATOLOGY: Yes
- Time schedule for collection of blood: daily
- Anaesthetic used for blood collection: Yes (identity)
- Animals fasted: No data
- How many animals: 5 per sex per group


CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood:
- Animals fasted: No data



URINALYSIS: Yes
- Time schedule for collection of urine:
- Metabolism cages used for collection of urine: Yes


NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations:
- Dose groups that were examined:
- Battery of functions tested: grip strength

Sacrifice and pathology:

Histological examinations were performed on organs and tissues from all control and high dose animals, and all gross lesions
from all animals.
From the animals of the low and middle dose groups, the livers, spleens and thyroid glands were
examined to establish a no-effect level.

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:

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:

no effects observed

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

no effects observed

Details on results:

Oral administration of TKA 40270 (CGPS 345) to Wistar rats at doses of 60, 200 and
600 mg/kg/day, for 28 days did not induce test item-related deaths nor relevant clinical signs
during daily and weekly observations. The functional observational battery (week 4) did not
reveal any relevant changes. Food consumption was unaffected and no test item-related changes
of toxicological relevance in the hematology or urinalysis parameters at any dose level.
Test item-related reductions in the body weight development were seen in both sexes treated
with 200 mg/kg/day and 600 mg/kg/day. Changes in clinical biochemistry parameters, indicative
of changes in liver metabolism, were considered to be largely metabolic and adaptive in nature,
and were largely reversible by the end of the recovery period.
These findings were evident in females at 200 mg/kg/day and both sexes at 600 mg/kg/day and
correlated with organ weight changes and histopathological findings in the liver. Liver weight
changes were seen in males and females at all dose levels, and macroscopically observed liver
enlargement was associated with increased centrilobular hepatocellular hypertrophy. This latter
liver finding, minimal in severity, was noted in only two males at the end of the 2-week recovery
period, which was considered to be indicative of reversibility.
Kidney weights were increased in males at 200 mg/kg/day and 600 mg/kg/day without any
relevant histopathological correlate.
Furthermore, increased extramedullary hemopoiesis in the spleen and increased follicular cell
hypertrophy in the thyroid gland were observed in males and females treated at 200 and
600 mg/kg/day and were largely reversible after the recovery period.
Based on the results of this study, the no-observed-effect-level (NOEL) was below the lowest dose tested (60 mg/kg/day). However, considering the nature and reversibility of the findings noted, the no-observed-adverse-effect-level (NOAEL) was established at 600 mg/kg body weight/day.
.

Effect levels

Dose descriptor:

NOAEL

Effect level:

600 mg/kg bw/day (actual dose received)

Sex:

male/female

Basis for effect level:

other: liver effects

Target system / organ toxicity

Critical effects observed:

not specified