Registration Dossier

Toxicological information

Toxicity to reproduction

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Administrative data

Endpoint:
screening for reproductive / developmental toxicity
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
from 2011-11-21 to 2012-07-05
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study
Justification for type of information:
A combined 28-day toxicity study with the reproduction/developmental toxicity sreening test (OECD 422) by oral gavage with the reaction mass of potassium trifluoroacetate (TFAK) and potassium trifluoromethanesulphinate (TFSK) was identified and used as supporting study for the endpoint toxicity to reproduction.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012
Report Date:
2012

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Remarks:
2011-07-19
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Test material form:
liquid
Remarks:
aqueous solution
Details on test material:
Reaction mass of potassium trifluoroacetate and potassium trifluoromethanesulphinate / 911-467-3
Specific details on test material used for the study:
In this study, the dose-levels of the test item are expressed in terms of active material TFSK/TFAK. The analytical purity of the test substance was 37.9% (potassium triflinate 19% and potassium trifluoroacetate 19.8%) and ca. 61.4% water. In this study the test material was dosed at concentrations of 100, 300 and 1000 mg/kg based on active ingredient which corresponds to 50; 150 and 500 mg/kg potassium trifluoroacetate.

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source:Charles River Laboratories France, L’Arbresle, France. Crl CD® (SD) IGS BR, Caesarian Obtained, Barrier Sustained-Virus Antibody Free, (COBS-VAF®).
- Age at study initiation: the males were approximately 10 weeks old, the females were approximately 9 weeks old
- Weight at study initiation: males: a mean body weight of 383 g (range 359 g to 421 g), and female a mean body weight of 211 g (range: 186 g to 236 g).
- Fasting period before study:
- Housing: The animals were individually housed, except during pairing, in polycarbonate cages (UAR, 43.0 cm x 21.5 cm x 18 cm) with stainless steel lids, and containing autoclaved sawdust (SICSA, Alfortville, France).
Toward the end of gestation and during lactation with their litter, autoclaved wood shavings (SICSA Alfortville, France) was provided as nesting material, a few days before delivery and during the lactation period.
Nylabone was given as enrichment of the environment of the rats.
The cages were placed in numerical order on the racks.
- Diet (e.g. ad libitum): The animals had free access to SSNIFF R/M-H pelleted maintenance diet, batch No. 7055973 (SSNIFF Spezialdiäten GmbH, Soest, Germany) which was distributed weekly.
- Water (e.g. ad libitum): The animals had free access to bottles containing tap water (filtered with a 0.22 µm filter)
- Acclimation period: the animals were acclimated for a period of 5 days before the beginning of the treatment period.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 2°C
- Humidity (%): 50 ± 20%
- Air changes (per hr): about 12 cycles/hour of filtered, non-recycled air.
- Photoperiod (hrs dark / hrs light): 12h/12h (7:00 - 19:00)

IN-LIFE DATES: From:2011-11-24 To: 2012-01-24

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
water
Details on exposure:
PPREPARATION OF DOSING SOLUTIONS:
In this study, the dose-levels of the test item were expressed in terms of active material TFSK/TFAK. Since active material of the test item is the sum of 19% TFSK and 18.9% TFAK (total of 37.9%), the quantities of test item used for preparation of the dosage forms were corrected by a correction factor of 2.64.
The test item was administered as a solution in the vehicle. The test item was mixed with the required quantity of vehicle. The dosage formulations were prepared for 2 to 8 days (frequency based on the results of the stability study CIT/Study No. 38264 AHS). The dosage forms were stored and delivered at room temperature and protected from light (see § Study plan adherence).

VEHICLE
drinking water treated by reverse osmosis using an ELIX 5 apparatus
- Concentration in vehicle: 0, 100, 300 and 1000 mg/kg of active ingredient
- Amount of vehicle (if gavage): 5 mL/kg
Details on mating procedure:
- M/F ratio per cage:1/1
- Length of cohabitation: until mating occurs or 14 days
- Proof of pregnancy: vaginal plug or sperm in a vaginal lavage. referred to as day 0 of pregnancy
- After 14 days of unsuccessful pairing replacement of first male by another male with proven fertility.
- Further matings after two unsuccessful attempts: no
- After successful mating each pregnant female was caged (how): Alone
- Any other deviations from standard protocol: No
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
The High Performance Liquid Chromatography with UV detection (HPLC/UV) analytical method for the determination of Reaction mass of TFSK/TFAK in dosage form samples was validated at CIT prior to dosage form analysis. The analytical method was validated for concentration ranging from 2 to 200 mg/mL.

The concentration of the test item in samples of each control and test item dosage form prepared for use in weeks 1, 3 and 5 was determined. In addition, the concentration of the test item in a sample of the high-dose test item form prepared for use in week 2 was determined.

Acceptance criterion: measured concentration = nominal concentration ± 10%

The validation of the analytical method was conducted in CIT/Study No. 38263 VAA and precise details concerning the checked parameters, acceptance criteria and obtained results were documented in the corresponding validation report.

Each analytical sequence consisted of at least:
+ A blank sample (diluent only),
+ Ten standard samples at nominal concentration, prepared from two independent standard solutions,
+ Study samples prepared from aliquots of the dosage forms.
The standard samples bracketed the dosage form samples.
The blank sample was checked for the absence of chromatographic interference.
Duration of treatment / exposure:
Males were exposed for 38 days, i.e. 2 weeks prior to mating, during mating, and up to termination. Females were exposed for maximum 57 days, i.e. during 2 weeks prior to mating, during mating, during post-coitum, and during at least 4 days of lactation.
Frequency of treatment:
Once a day at approximately the same time
Doses / concentrationsopen allclose all
Dose / conc.:
100 mg/kg bw/day (nominal)
Remarks:
other: active ingredient
Dose / conc.:
300 mg/kg bw/day (nominal)
Remarks:
other: active ingredient
Dose / conc.:
1 000 mg/kg bw/day (nominal)
Remarks:
other: active ingredient
No. of animals per sex per dose:
10 animals per sex and per dose
Control animals:
yes, concurrent vehicle
Details on study design:
In a previous study (CIT/Study No. 38258 TSR), Reaction mass of TFSK/TFAK (batch No. SSK1278645) was given to rats (three/sex/group), by daily oral administration (gavage) for 2 weeks at 0, 150, 550 or 1000 mg/kg/day active ingredient. Ptyalism was observed in 2/3 males and in 1/3 females given 1000 mg/kg/day for 2 to 4 days during the second week of treatment. This clinical sign was attributed to the test item. Reflux at dosing was observed in 1/3 females given 500 mg/kg/day active ingredient on day 15. Soft feces, alopecia and scabs were noted in some animals; as these findings were isolated and/or without any dose relationship, they were considered as incidental.
Body weight and food consumption were considered to be unaffected by the treatment with the test item. On necropsy, there were no test item-related macroscopic post-mortem findings.
Therefore 1000 mg/kg/day, which is also the maximum recommended dose to be tested according to OECD Guideline No. 422, was selected as the high dose-level. The low-dose and mid-dose were selected using a ratio representing a three-fold interval (i.e. 100 and 300 mg/kg/day active ingredient).

Examinations

Parental animals: Observations and examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: once a day before the treatment period and at least twice a day during the treatment period

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Detailed clinical examinations were performed on all animals outside the home cage, in a standard arena, once before the beginning of the treatment period and then once a week until the end of the study.

BODY WEIGHT: Yes
- Time schedule for examinations:
+ males: on the first day of treatment (day 1), then once a week until sacrifice.
+ femelles: on the first day of treatment (day 1), then once a week until mated and on days 0, 7, 14 and 20 p.c. and days 1 and 5 p.p..
The body weight of female sacrificed on day 25 p.c. for no delivery was recorded the day of sacrifice, presented in the report but not including in the statistical evaluation.


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
The quantity of food consumed by each male was measured once a week, over a 7 day period, from the first day of treatment until the start of the pairing period.
The quantity of food consumed by each female was measured once a week, over a 7 day period, from the first day of treatment until the start of pairing period, during pregnancy at the intervals days 0-7, 7-14 and 14-20 p.c. and during lactation for interval days 1 5 p.p..
During the pairing period, the food consumption was measured neither for males nor females.
Food intake per animal and per day was calculated by noting the difference between the food given and that in the food-hopper the next time.

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

OPHTHALMOSCOPIC EXAMINATION: Yes pupillary reflex during the FOB test
- Dose groups that were examined: 5 males and 5 female per group

HAEMATOLOGY: Yes
- Time schedule for collection of blood: on the day of sacrifice
- Anaesthetic used for blood collection: Yes light isoflurane anesthesia
- Animals fasted: Yes for an overnight period of at least 14 hours
- How many animals: the first five males and the first five females to deliver from each group
- Parameters checked in table were examined.

CLINICAL CHEMISTRY: Yes / No / No data
- TTime schedule for collection of blood: on the day of sacrifice
- Anaesthetic used for blood collection: Yes light isoflurane anesthesia
- Animals fasted: Yes for an overnight period of at least 14 hours
- How many animals: the first five males and the first five females to deliver from each group
- Parameters checked in table were examined.

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: once at the end of the treatment period
- Dose groups that were examined: The first five males and the first five females to deliver
- Battery of functions tested:
+"touch escape" or ease of removal from the cage
+In the hand: fur appearance, salivation, lachrymation, piloerection, exophthalmos, reactivity to handling, pupil size (presence of myosis or mydriasis)
+ In the standard arena (2-minute recording): grooming, palpebral closure, defecation, urination, tremors, twitches, tonic and clonic convulsions, gait, arousal (hypo- and hyper-activity), posture, stereotypy, behavior, breathing, ataxia and hypotonia
+ The following parameter measurements, reflexes and responses were recorded:
 touch response,
 forelimb grip strength,
 pupillary reflex,
 visual stimulus response,
 auditory startle reflex,
 tail pinch response,
 righting reflex,
 landing foot splay,
 at the end of observation: rectal temperature.

OTHER:
+ at the end of observation: rectal temperature.
+Motor activity of all animals was measured once by automated infra-red sensor equipment over a 60-minute period
Oestrous cyclicity (parental animals):
The estrous cycle stage was determined from a fresh vaginal lavage (stained with methylene blue), each morning during the pairing period, until the females are mated.
Sperm parameters (parental animals):
No data
Litter observations:
Each live pup was identified individually on day 1 p.p., by subcutaneous injection of Indian ink.

Litter size
The total litter size and numbers of pups of each sex were recorded as soon as possible after birth. Any gross malformations in pups were noted.
The litters were observed daily in order to note the number of live, dead and cannibalized pups.

Clinical signs
The pups were observed daily for clinical signs or abnormal behavior.

Body weight
The body weight of each pup was recorded on days 1 and 5 p.p..
Postmortem examinations (parental animals):
SACRIFICE
GROSS PATHOLOGY: Yes
Parent animals:
A complete macroscopic post-mortem examination was performed on all parent animals. This included examination of the external surfaces, all orifices, the cranial cavity, the external surfaces of the brain and spinal cord, the thoracic, abdominal and pelvic cavities with their associated organs and tissues and the neck with its associated organs and tissues. The numbers of corpora lutea and implantation sites were also recorded for females sacrificed as scheduled on day 6 post partum and for female sacrificed on day 25 post-coitum due to no delivery. For apparently non-pregnant females the presence of implantation scars on the uterus was checked using the ammonium sulphide staining technique.
Pup examinations:
A macroscopic post-mortem examination of the principal thoracic and abdominal organs was performed on all pups showing relevant external abnormalities. No tissues were preserved.

HISTOPATHOLOGY: Yes (see table)
Postmortem examinations (offspring):
A macroscopic post-mortem examination of the principal thoracic and abdominal organs was performed on all found dead pups. Special attention was paid to whether the pup had fed (e.g. presence of milk in the stomach). No tissues were preserved.

GROSS NECROPSY
A macroscopic post-mortem examination of the principal thoracic and abdominal organs was performed on all pups showing relevant external abnormalities. No tissues were preserved.
Statistics:
see attached documents statistique.doc
Reproductive indices:
pre-implantation loss:
Number of corpora lutea - Number of implantation sites
_____________________________________________ x 100
Number of corpora lutea

post-implantation loss:
Number of implantation sites - Number of live pups
_____________________________________________ x 100
Number of implantations

mating index:
Number of mated animals
_____________________ x 100
Number of paired animals

fertility index:
Number of pregnant female partners
_______________________________ x 100
Number of mated pairs

gestation index:
Number of females with live born pups
________________________________ x 100
Number of pregnant females
Offspring viability indices:
live birth index:
Number of live born pups
_____________________ x 100
Number of delivered pups

viability index on day 4 post-partum:
Number of surviving pups on day 4 post-partum
_______________________________________ x 100
Number of live born pups

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

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
Haematological findings:
effects observed, treatment-related
Description (incidence and severity):
In males at 1000 mg/kg/day there was a minimal decrease in hemoglobin content (considered as minor toxicological significance).
Clinical biochemistry findings:
effects observed, treatment-related
Description (incidence and severity):
In males at 1000 mg/kg/day there was a minimal increase in inorganic phosphorus content and a light decrease in calcium content (considered as minor toxicological significance).
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Description (incidence and severity):
The test item administration induced minimal centrilobular hypertrophy of hepatocytes in males and females at 1000 mg/kg/day, and in males at 300 mg/kg/day.
This microscopic change correlated with increased liver weights.
This change was not considered to be adverse in view of the absence of associated degenerative microscopic findings or clinical pathology changes in liver enzyme activities.

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:
no effects observed
Reproductive performance:
no effects observed

Details on results (P0)

CLINICAL SIGNS AND MORTALITY
There were no unscheduled deaths and no clinical signs related to the treatment with the test item.

BODY WEIGHT AND WEIGHT GAIN
There were no effects on mean body weight or mean body weight change, either in males or females.

FOOD CONSUMPTION
There were no effects on food consumption.

HAEMATOLOGY
In males and at 1000 mg/kg/day active ingredient there was a minimal decrease in hemoglobin content (-10.2% vs. controls, p <0.01).
Taking into account the amplitude of the changes and in absence of relevant effect in other parameters, a relationship with the test item treatment was considered unlikely up to 300 mg/kg/day active ingredient and of minor toxicological significance at 1000 mg/kg/day active ingredient (males only)

CLINICAL CHEMISTRY
In males and at 1000 mg/kg/day active ingredient there was a minimal increase in inorganic phosphorus content (+13.4% vs. controls, p <0.05) and a light decrease in calcium content (-4.9% vs. controls, p<0.05).
Taking into account the amplitude of the changes and in absence of relevant effect in other parameters, a relationship with the test item treatment was considered unlikely up to 300 mg/kg/day active ingredient and of minor toxicological significance at 1000 mg/kg/day active ingredient (males only).
Other statistically significant differences (chloride, glucose and albumin) and were minimal, without any dose-level relationship and/or in one sex only. Therefore a treatment-related effect was considered unlikely.


NEUROBEHAVIOUR
There were no relevant differences in treated groups when compared with control group.

ORGAN WEIGHTS
The mean absolute and relative liver weights were increased in males treated at 300 or 1000 mg/kg/day active ingredient. These variations were statistically significant. Minimal, not statistically significant increases were also seen in females at 1000 mg/kg/day active ingredient. This increase correlated with microscopic changes observed in the liver.
There were statistically significant increases of the mean absolute and relative kidney weights in females treated at 1000 mg/kg/day active ingredient. In view of the low amplitude of the changes and the absence of microscopic correlates, these variations were considered to be of minor toxicological significance
Other organ weight changes were not considered to be related to the test item as they were small in amplitude, had no gross or microscopic correlates, and/or were not dose-related in magnitude

GROSS PATHOLOGY
There were no macroscopic changes attributed to the test item administration.
The few macroscopic findings noted had no histologic correlates or correlated with common histologic findings in control Sprague-Dawley rats, and were considered to be incidental.


HISTOPATHOLOGY: NON-NEOPLASTIC
The test item administration induced minimal centrilobular hypertrophy of hepatocytes in 4/5 males and 2/5 females at 1000 mg/kg/day active ingredient, and in 1/5 males at 300 mg/kg/day active ingredient. This microscopic change correlated with increased liver weights. This change was not considered to be adverse in view of the absence of associated degenerative microscopic findings or clinical pathology changes in liver enzyme activities.
In males given the test item at all dose-levels, the incidence and severity of hematopoiesis in the spleen were minimally increased compared to controls. This increased hematopoiesis may have been compensatory to the changes in red blood cell parameters.
There were no microscopic changes attributed to the test item administration in the male and female genital organs.
Other microscopic findings noted in treated animals were considered incidental changes, as they also occurred in controls, were of low incidence, had no dose-relationship in incidence or severity, and/or are common background findings for the Sprague-Dawley rat.

Effect levels (P0)

open allclose all
Dose descriptor:
NOEL
Remarks:
Parental toxicity
Effect level:
1 000 mg/kg bw/day (nominal)
Based on:
act. ingr.
Sex:
male/female
Basis for effect level:
other: Effects considered to be of minor toxicological significance
Remarks on result:
other: Histopathological observation: Centrilobular hepatocellular hypertrophy but not judged adverse (in view of the absence of associated degenerative microscopic findings or clinical pathology changes in liver enzyme activities).
Dose descriptor:
NOEL
Remarks:
Parental reproductive performance
Effect level:
1 000 mg/kg bw/day (nominal)
Based on:
act. ingr.
Sex:
male/female
Basis for effect level:
other: mating and fertility

Results: F1 generation

General toxicity (F1)

Clinical signs:
no effects observed
Mortality / viability:
no mortality observed
Body weight and weight changes:
no effects observed
Sexual maturation:
not examined
Organ weight findings including organ / body weight ratios:
not examined
Gross pathological findings:
no effects observed
Histopathological findings:
not examined

Details on results (F1)

VIABILITY (OFFSPRING)
There were no treatment-related effects on pup mortality

CLINICAL SIGNS (OFFSPRING)
There were no clinical signs in pups considered to be treatment-related

BODY WEIGHT (OFFSPRING)
There were no effects on mean body weight neither in male nor in female pups during the lactation period (day 1 or day 5 p.p.).

GROSS PATHOLOGY (OFFSPRING)
There were no treatment-related findings in found dead or pups sacrificed on day 5 p.p..

Effect levels (F1)

Dose descriptor:
NOEL
Generation:
F1
Effect level:
1 000 mg/kg bw/day (nominal)
Based on:
act. ingr.
Sex:
male/female
Basis for effect level:
other: Any treatment-related effect on pups at 1000 mg/kg/day

Overall reproductive toxicity

Reproductive effects observed:
no

Any other information on results incl. tables

The summary of mating datais presented in the following table:

 

Dose-level (mg/kg/dayactive ingredient)

0

100

300

1000

Number of animals paired (M + F)

10 + 10

10 + 10

10 + 10

10 + 10

Number of males mated

9

10

10

10

Number of females mated

10

10

10

10

Mean number of days taken to mate

3.6

3.0

2.0

3.4

Number of pregnant females

10

10

9

10

Male fertility index

90%

100%

100%

100%

Female fertility index

100%

100%

90%

100%

M: males; F: females.

 

The summary of delivery datais presented in the following table:

 

Dose-level (mg/kg/dayactive ingredient)

0

100

300

1000

Number of pregnant females

10

10

9

10

Number of females which delivered

10

10

9

10

Mean duration of gestation (days)

21.3

21.6

21.4

21.4

Mean number ofcorpora luteaper female

18.1

16.9

17.3

18.9

Mean number of implantation sites per female

17.2

15.7

15.9

15.8

Mean pre-implantation loss (%) per female

4.6

6.6

8.8

14.6

Mean number of pups delivered per female

15.0

13.7

15.0

14.1

Mean post-implantation loss (%)aper female

11.5

12.4

4.5

11.1

Viability index on day 4p.p.(%) per female

90.7

99.3

96.3

96.5

a: manually calculated, no statistics performed.

 

The number of pups found dead and the number of litters affected

Dose-level (mg/kg /dayactive ingredient)

0

100

300

1000

Number of pups found dead (litter)

5 (2)

1 (1)

5 (3)

2 (2)

Number of pups cannibalized (litter)

10 (3)

0

1 (1)

3 (2)

Number of pups prematurely sacrificed

0

0

0

0

 

 

The live birth, viability and lactation indexes

 

Dose-level (mg/kg/dayactive ingredient)

0

100

300

1000

Live Birth Index (%)

100

100

100

100

Viability Index (day 4p.p., %).

90.7

99.3

96.3

96.5

Lactation Index (day 5p.p., %)

99.3

100.

99.2

100

 

 

Macroscopicpost-mortemexamination of pups

Dose-level (mg/kg/dayactive ingredient)

0

100

300

1000

Dead pups

 

 

 

 

Number of pup examined (litter)

5 (2)

1 (1)

5 (3)

2 (2)

Autolysis

1 (1)

0

0

0

Stomach: absence of milk

1 (1)

1 (1)

3 (2)

2 (2)

Total pup dead observations

2 (1)

1 (1)

3 (2)

2 (2)

Schedule sacrificed pups

 

 

 

 

Number of pup examined (litter)

0

0

1 (1)

1 (1)

Cutaneous lesion

0

0

0

1 (1)

Total pup scheduled sacrifice observations

0

0

0

1 (1)

 

 

Applicant's summary and conclusion

Conclusions:
The test item, Reaction mass of TFSK/TFAK, was administered daily by gavage to male and female Sprague Dawley rats, for 2 weeks before mating, during mating, and (for females) throughout gestation and until day 5 post partum, at dose-levels of 100, 300 or 1000 mg/kg/day active ingredient (approximately 38 days for males and at maximum 57 days for females).
Slight but non adverse effects were observed in the liver from parent animals..
No effect on reproductive performance or reproductive organs was observed.
In pups, there were no treatment-related findings.
Based on the experimental conditions of this study:
- The No Observed Adverse Effect Level (NOAEL) for parental toxicity was considered to be 1000 mg/kg/day active ingredient,
- The No Observed Effect Level (NOEL) for reproductive performance (mating and fertility) was considered to be 1000 mg/kg/day active ingredient,
- The No Observed Effect Level (NOEL) for toxic effects on progeny was considered to be 1000 mg/kg/day active.
Executive summary:

The purpose of this study (OECD 422 , GLP), was to generate information concerning the effects of TFSK/TFAK on the possible health hazards likely to arise from repeated exposure over a relatively limited period of time. In addition it provides information on possible effects on male and female reproductive performance such as gonadal function, mating behavior, conception, development of the conceptus and parturition.

TFSK/ TFAK was administered to male rats for at least 38 days and to female rats for 14 days prior to pairing, through the pairing and gestation periods until the F1 generation reached day 4 post partum.

The following dose levels were applied:

Group 1: 0 mg/kg body weight/day (control group)

Group 2: 100 mg/kg body weight/day

Group 3: 300 mg/kg body weight/day

Group 4: 1000 mg/kg body weight/day

A dose volume of 5 mL/kg body weight with a daily adjustment to the actual body weight was used. Control animals were dosed with the vehicle alone (distilled water).

The following results were obtained:

In parent animals, in males and females, body weight and body weight gain were not considered to be affected by the treatment with the test item. At 300 and 1000 mg/kg/day a centrilobular hepatocellular hypertrophy was observed in some animals. This microscopic change correlated with increased liver weights. In view of the absence of associated degenerative microscopic findings or clinical pathology changes in liver enzyme activities this change was considered to be non adverse.

 

No effect on reproductive performance or parental reproductive organs was observed. In pups, the mean number of pups at first litter check and on day 4 post partum was not affected by the treatment with the test item. The sex ratio was also not affected, and weight development was not affected by the treatment with the test item. At necropsy of pups, no test item-related findings were noted.

 

Based on the experimental conditions of this study:

-         The No Observed Adverse Effect Level (NOAEL) for parental toxicity was considered to be 1000 mg/kg/day active ingredient (corresponding to 500 mg TFAK/kg/day),

-         the No Observed Effect Level (NOEL) for reproductive performance (mating and fertility) was considered to be 1000 mg/kg/day active ingredient (corresponding to 500 mg TFAK/kg/day),

-         the No Observed Effect Level (NOEL) for toxic effects on progeny was considered to be 1000 mg/kg/day active ingredient (corresponding to 500 mg TFAK/kg/day).