Neryl acetate

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

An oral diet repeated dose toxicity study combined with a reproduction/developmental toxicity screening test was conducted with NERYL ACETATE according to guideline OECD 422 and in compliance with GLP.

The NOAEL for systemic and reproductive / developmental toxicity was 7500 ppm, corresponding to 440 mg/kg bw/day for males, 471-547 mg/kg bw/day during the gestation period and 624-1080 mg/kg bw/day during the lactation period for reproductive females.

Link to relevant study records

Reference

Endpoint:

screening for reproductive / developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

30 April to 10 October 2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)

Deviations:

no

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Species:

rat

Strain:

Crj: CD(SD)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River (UK) Limited
- Age of F0 animals at study initiation: Approximately 10 weeks
- Weight at study initiation: Males: 338-383 g; Females: 207-259 g
- Housing: No. of animals per cage - Males: pre pairing and post pairing - up to 5 animals; Females: pre pairing - up to 5 animals; During pairing - one male and one female; Gestation - one female; Lactation: one female + litter. Toxicity phase and recovery phase - up to five animals of one sex. Cages comprised of a polycarbonate body with a stainless steel mesh lid. Solid (polycarbonate) bottom cages were used during the acclimatisation and treatment period with the exception of pairing periods. Grid bottomed cages comprising of polypropylene body were used during pairing.
- Diet: SDS VRF1 Certified powdered diet, ad libitum
- Water: Potable water from the public supply via polycarbonate bottles with sipper tubes, ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature: 19-23 °C
- Humidity: 40-70 %
- Air changes: Filtered fresh air which was passed to atmosphere and not recirculated.
- Photoperiod: 12 h dark / 12 h light

Route of administration:

oral: feed

Vehicle:

other: carrier diet, including corn oil

Details on exposure:

DIET PREPARATION
- Carrier diet: SDS VRF1 certified diet.
- Stabiliser: Corn oil (test material to corn oil ratio 5:1)
- Method of preparation: On each occasion of the preparation of the premix the required amount of test substance and corn oil were mixed together and stirred. The mixture was added to an equal amount of plain diet and stirred until visibly homogenous. This doubling up process was repeated until half of the final weight of premix was achieved or the mixture appeared dry. This mixture was then ground using a mechanical grinder after which it was made up to the final weight of the premix with plain diet. This premix was mixed in a Turbula mixer for 100 cycles to ensure the test substance was dispersed in the diet. Aliquots of the premix were then diluted with further quantities of plain diet to produce the required dietary concentrations. Each batch of treated diet was mixed for a further 100 cycles in a Turbula mixer.
For Control diet the corn oil was added directly to the diet and then prepared as indicated for the premix.
- Frequency of preparation: Weekly, however, preparations on some occasions were made in advance and stored frozen, but were used within the frozen stability period (22 days when stored frozen nominally -20 °C).
- Storage of preparation: Frozen (nominally -20 °C).

GROUPS
Groups 1, 2, 3 and 4: 0, 1000, 2500 and 7500 ppm, respectively

Details on mating procedure:

- Toxicity phase and recovery phase males were paired with reproductive phase females. Toxicity and recovery phase females were not paired for mating.
- M/F ratio per cage: 1:1 from within the same treatment groups
- Pairing commenced: After three weeks of treatment
- Length of cohabitation: Up to 3 weeks
- Proof of pregnancy: Presence of sperm within the vaginal smear and/or ejected copulation plugs referred to as Day 0 of pregnancy.
- Male/female separation: Day when mating evidence was detected.
- Pre-coital interval: Calculated for each female as the time between first pairing and evidence of mating.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Stability and homogeneity: Before commencement of treatment, the suitability of the proposed mixing procedures was determined and specimen formulations at 100 and 20000 ppm were analysed to assess the stability and homogeneity of the test substance in the diet matrix. Stability was confirmed as eight days at ambient temperature and 22 days when stored frozen. However, only one day ambient stability was used.
Achieved concentration: Samples of each formulation prepared for administration in Weeks 1 and 5 of treatment were analysed for achieved concentration of the test substance.

Duration of treatment / exposure:

Toxicity phase males were treated daily for three weeks before pairing, throughout pairing and up to necropsy after a minimum of five consecutive weeks.
Toxicity phase females were treated daily for a minimum of five consecutive weeks up to necropsy in Week 6.
Reproductive females were treated daily for three weeks before pairing, throughout pairing, gestation and until Day 6 of lactation.
High dose Recovery phase male and female rats were treated daily for a minimum of six consecutive weeks, followed by a 14 day period without treatment.

Frequency of treatment:

Continuously (fresh diet given daily). During the recovery period, all animals were given untreated diet (without corn oil).

Dose / conc.:

1 000 ppm

Remarks:

nominal in diet

Dose / conc.:

2 500 ppm

Remarks:

nominal in diet

Dose / conc.:

7 500 ppm

Remarks:

nominal in diet

No. of animals per sex per dose:

Reproduction phase: 10 females/dose for all dose groups
Toxicity phase : 5 animals/sex/dose for vehicle and high dose groups; 10 males/dose for 1000 and 2500 ppm dose groups; 5 females/dose for 1000 and 2500 ppm dose groups
Recovery phase: 5 animals/sex/dose for vehicle and high dose groups

Control animals:

other: control group was provided with the carrier diet, including corn oil

Details on study design:

- Dose selection rationale: Dose levels were selected in conjunction with the Sponsor following the completion of the dose range finder study (Study number OAD0022). In the dose range finding study the doses of 1500, 7500 or 15000 ppm were well tolerated (no mortality), no adverse clinical signs or macroscopic changes in organ appearance were detected at any dose level. Effects of treatment at 15000 ppm included initial body weight loss for the first few days of treatment in males and females, associated with lower food consumption, probably due to low palatability of the treated diet. In males, no effects on body weight and body weight gain were observed up to 7500 ppm but the overall bodyweight change in the high dose group was 23% lower compared to Control group. In females, body weight gain was lower than Control group at 7500 and 15000 ppm, especially during Days 1-7 and 15-22, leading to overall body weight gains 64% and 46% lower than Control group, respectively. The lower bodyweight gain observed in the mid dose group was mainly due to one female showing overall bodyweight loss during the treatment period (-3 g). However, even without this animal, the body weight gain in this group was only 50% of the Control group. Therefore, the high dose to be tested in the main study was considered to be 7500 ppm due to the toxicity observed in females. Then, the lower doses were spaced approximately by a 2.5 to 3-fold factor, i.e. 2500 and 1000 ppm.

- Rationale for animal assignment: Randomly allocated on arrival. Using the sequence of cages in the battery, one animal at a time was placed in each cage with the procedure being repeated until each cage held the appropriate number of animals. Each sex was allocated separately.

Positive control:

Not applicable

Parental animals: Observations and examinations:

CLINICAL OBSERVATIONS: Yes
- Time schedule: Animals were inspected visually at least twice daily for evidence of ill-health or reaction to treatment. Cages were inspected daily for evidence of animal ill-health amongst the occupant(s).
During the acclimatisation and recovery periods, observations of the animals and their cages were recorded at least once per day

NEUROBEHAVIOURAL EXAMINATION: Yes
Detailed physical examination and arena observations: Before treatment commenced and during each week of treatment and recovery, detailed physical examination and arena observations were performed on each adult animal.
- Time schedule:
- Sensory reactivity and grip strength: Sensory reactivity and grip strength assessments were performed on all recovery animals in Groups 1 and 4 and the five lowest numbered surviving toxicity phase males and females in Groups 2 and 3, during Week 6 of treatment.
- Motor activity:
During Week 6 of treatment, the motor activity of all recovery animals in Groups 1 and 4 and the five lowest numbered surviving toxicity phase males and females in Groups 2 and 3 was measured.

BODY WEIGHT: Yes
- Time schedule for examinations:
Toxicity and Recovery phase animals: Before feeding on the day that treatment commenced (Day 1), weekly thereafter and before necropsy.
Reproductive females: Before feeding on the day that treatment commenced (Day 1), weekly before pairing, on Days 0, 6, 13 and 20 after mating, on Days 1, 4 and 7 of lactation and before necropsy.

FOOD CONSUMPTION: Yes
- Time schedule for examinations:
Toxicity and recovery phase males and females: Daily. From these records the mean daily consumption per animal (g/rat/day) was calculated for each cage. Food consumption was not recorded for males during the period when paired for mating (Day 22 to 28). Food consumption recordings recommenced on Day 29.
- Reproductive phase females: Daily until paired for mating. From these records the mean daily consumption per animal (g/rat/day) was calculated for each cage.
Following pairing, on Days 0-5, 6-12 and 13-19 after mating and Days 1-3 and 4-6, of lactation. From these records the mean daily consumption (g/rat/day) was calculated for each animal.

HAEMATOLOGY AND CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood:
Haematology: Week 6 - Five lowest numbered toxicity phase males and females per group; Recovery Week 2 - All recovery phase animals
Clinical chemistry: Week 6 - Five lowest numbered toxicity phase males and females per group; Recovery Week 2 - All recovery phase males
- Animals fasted: Yes, Blood samples were collected after overnight withdrawal of food.
- Animals were held under light general anaesthesia induced by isoflurane. Blood samples were withdrawn from the sublingual vein.
- Haematology parameters: Haematocrit, Haemoglobin concentration, Erythrocyte count (RBC), Absolute reticulocyte count, Percentage reticulocyte count, Mean cell haemoglobin, Mean cell haemoglobin concentration, Mean cell volume, Red cell distribution width, Total leucocyte count, Differential leucocyte count: Neutrophils, Lymphocytes, Eosinophils, Basophils, Monocytes, Large unstained cells, Platelet count, Morphology: Anisocytosis, Macrocytosis, Microcytosis, Hypochromasia, Hyperchromasia, Prothrombin time and Activated partial thromboplastin time.
- Blood Chemistry parameters: Alkaline phosphatase (ALP), Alanine aminotransferase (ALT), Aspartate aminotransferase (AST), Gamma-glutamyl transpeptidase (gGT), Total bilirubin, Bile acids, Urea, Creatinine, Glucose, Total cholesterol, Triglycerides, Sodium (Na), Potassium (K), Chloride (Cl), Calcium (Ca), Inorganic phosphorus, Total protein, Albumin and Albumin/globulin ratio (A/G Ratio).

PARTURITION OBSERVATIONS AND GESTATION LENGTH:
- Duration of gestation: Time elapsing between the detection of mating and commencement of parturition.
- Parturition observations: From Day 20 after mating, females were inspected three times daily for evidence of parturition. The progress and completion of parturition was monitored, numbers of live and dead offspring were recorded and any difficulties observed were recorded.

Oestrous cyclicity (parental animals):

- Dry smears: Daily smears were taken for 15 days before pairing, using cotton swabs moistened with saline. Smears were subsequently examined to establish the duration and regularity of the oestrous cycle.
- Wet smears: After pairing with the male, daily smearing was continued using pipette lavage, until evidence of mating was observed.

Litter observations:

PARAMETERS EXAMINED
- Clinical observations: Examined at approximately 24 h after birth (Day 1 of age) and then daily thereafter for evidence of ill health or reaction to treatment; these were on an individual offspring basis or for the litter as a whole, as appropriate.
- Litter size: Daily records were maintained of mortality and consequent changes in litter size from Days 1-7 of age.
- Sex ratio: The sex ratio of each litter was recorded on Days 1, 4 and 7 of age.
- Individual offspring bodyweights: F1 offspring - Days 1, 4 and 7 of age.

Postmortem examinations (parental animals):

SACRIFICE
- Toxicity phase animals: Following completion of Week 6 investigations
- Reproductive phase females: Scheduled kill - Day 7 of lactation; Failing to produce viable litter - Day 25 after mating.
- Recovery phase animals: After at least 14 days without treatment.
- Method of sacrifice: F0 animals were killed by Carbon dioxide asphyxiation with subsequent exsanguination.

GROSS NECROPSY
- All adult animals were subject to a detailed necropsy. All external features and orifices were examined visually. Any abnormality in the appearance or size of any organ and tissue (external and cut surface) was recorded and the required tissue samples preserved in appropriate fixative. In addition the number of uterine implantation sites recorded.

HISTOPATHOLOGY / ORGAN WEIGHTS
For bilateral organs, left and right organs were weighed together.
Histology
Fixation: Tissues were routinely preserved in 10 % Neutral Buffered Formalin with the exception of Testes in modified Davidson’s fluid; Eyes In Davidson’s fluid.
Processing: Tissue samples were dehydrated, embedded in paraffin wax and sectioned at a nominal four to five micron thickness. For bilateral organs, sections of both organs were prepared. A single section was prepared from each of the remaining tissues required.
The five lowest numbered males and females in Groups 1 and 4 at scheduled termination.
Abnormalities only: All animals
- Routine staining: Sections were stained with haematoxylin and eosin; in addition samples of the testes were stained using a standard periodic acid Schiff (PAS) method.

Postmortem examinations (offspring):

SACRIFICE:
- F1 offspring scheduled kill: Day 7 of age
- Method of sacrifice: Intraperitoneal injection of sodium pentobarbitone

GROSS NECROPSY
- Offspring at scheduled termination: All F1 offspring were examined externally; any offspring found to be externally abnormal were also examined internally.
- Premature deaths (before Day 7 of age): Missing offspring and those grossly autolysed or grossly cannibalised could not be examined. All other offspring dying before Day 7 of age were subject to fresh macroscopic examination, where possible (external and internal); this also included an assessment for the presence of milk in the stomach, where this was possible.

Statistics:

See section "Any other information on materials and methods incl. tables”.

Reproductive indices:

Mating Performance and Fertility:
- Percentage mating = (Number animals mating / Animals paired) x 100
- Conception rate (%) = (Number animals achieving pregnancy / Animals mated) x 100
- Fertility index (%) = (Number animals achieving pregnancy / Animals pairing) x 100

Gestation length
- Gestation index (%) = (Number of live litters born / Number pregnant) x 100

Offspring viability indices:

Survival indices:
- Post-implantation survival index (%) = (Total number of offspring born / Total number of uterine implantation sites) x 100
- Live birth index (%) = (Number of live offspring on Day 1 after littering / Total number of offspring born) x 100
- Viability index (%) = (Number of live offspring on Day 7 after littering / Number live offspring on Day 1 after littering) x 100

Sex ratio:
- Percentage males = (Number of males in litter / Total number of offspring in litter) x 100

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Body weight gain during Week 1 of treatment was reduced in males and female receiving 7500 ppm with statistical significance.
Overall body weight gain in males was similar to Controls up to 2500 ppm and was lower but not statistically significantly at 7500 ppm.
Overall bodyweight gains in female were statistically significantly lower than Controls in all treated groups, but a dose response was not apparent.
Overall mean bodyweight gain during gestation and lactation was considered unaffected by treatment with Neryl Acetate up to 7500 ppm, when compared with Controls although isolated differences could be observed.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Overall food consumption for males and toxicity phase females receiving Neryl Acetate up to 7500 ppm was unaffected by treatment.
Overall food consumption for reproductive phase females was unaffected during the pre-pairing phase of treatment when compared with Controls.
Food intake was slightly but statistically significantly lower during Days 2-5 of lactation for females receiving 7500 ppm, leading to an overall reduction on food consumption of 20% when compared with Controls.

Food efficiency:

not specified

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

Statistically significantly lower group mean erythrocyte counts in males receiving 7500 ppm, and a slight but not statistically significant lower level for males receiving 2500 or 1000 ppm when compared with Controls.
Statistically significantly higher mean cell haemoglobin levels for males receiving 7500 ppm and slightly but statistically significant higher mean cell volume levels for males receiving 1000 ppm or above were observed.
Mean cell haemoglobin concentration was slightly but statistically significantly higher for females receiving 1000 ppm or above.
After 2 weeks of recovery haematological examinations were similar to that of the Controls. As a consequence these findings were considered to be of no toxicological significance.

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

effects observed, non-treatment-related

Description (incidence and severity):

All histological changes were considered to be unrelated to treatment.

Histopathological findings: neoplastic:

not examined

Other effects:

effects observed, treatment-related

Reproductive function: oestrous cycle:

no effects observed

Reproductive function: sperm measures:

not examined

Reproductive performance:

no effects observed

CLINICAL SIGNS AND MORTALITY (PARENTAL ANIMALS)
- There were no decedents in the study. Routine physical examination and arena observations did not reveal any abnormalities that were considered related to treatment with test item.

BODY WEIGHT (PARENTAL ANIMALS)
- Group mean bodyweight gain during Week 1 of treatment was reduced in males receiving 7500 ppm and females receiving 1000, 2500 and 7500 ppm when compared with Controls, with statistical significance being attained at 7500 ppm for both males and females. Bodyweight gain was slightly, but not statistically significantly lower during Weeks 4-5 for males receiving 2500 ppm and almost throughout treatment period for males receiving 7500 ppm when compared with Controls. Overall bodyweight gain in males was similar to Controls up to 2500 ppm and was lower but not statistically significantly at 7500 ppm (87% of Controls). Bodyweight gain was slightly, but not statistically significantly lower during Weeks 1-2, 3-4 and 4-5 for toxicity phase females receiving Neryl Acetate when compared with Controls, and overall bodyweight gains were statistically significantly lower than Controls in all treated groups, but a dose response was not apparent.
- Overall bodyweight change during the recovery period was slightly but not statistically significantly lower than Controls for males, and was higher for females (200% of Controls) that had received 7500 ppm, but no statistical significance was attained.
- During the first week of treatment (Weeks 0-1) bodyweight gain for reproductive phase females prior to pairing, was moderately but not statistically significantly lower for females receiving 7500 ppm when compared to Controls, resulting in the overall group mean bodyweight gain prior to pairing being slightly lower than Controls for this group. In the 2500 ppm group, 2 females had particularly low bodyweight gain prior to pairing but had normal bodyweight gain thereafter. When excluding those females from calculations, mean bodyweight gain of the group 2 reproductive phase females prior to pairing is similar to Controls (24 g vs. 26 g, for groups 2 and Controls, respectively). Therefore, it is considered that performance of females receiving 1000 or 2500 ppm was globally similar to Controls.
- Overall mean bodyweight gain during gestation and lactation was considered unaffected by treatment with Neryl Acetate up to 7500 ppm, when compared with Controls although isolated significant differences could be observed.

FOOD CONSUMPTION (PARENTAL ANIMALS)
- Overall food consumption for males and toxicity phase females receiving Neryl Acetate up to 7500 ppm was unaffected by treatment. Food intake was slightly lower on Day 1 of treatment for females receiving 7500 ppm when compared with Controls.
- Overall food consumption for reproductive phase females was unaffected during the pre-pairing phase of treatment when compared with Controls. Food intake was slightly lower on Day 1 of treatment for females receiving 7500 ppm when compared with Controls.
- Group mean food consumption on Day 0 of gestation was statistically significantly lower for females receiving 2500 or 7500 ppm when compared with Controls.
- Food intake was slightly but statistically significantly lower during Days 2-5 of lactation for females receiving 7500 ppm, leading to an overall reduction in food consumption of 20% when compared with Controls.

REPRODUCTIVE FUNCTION: ESTROUS CYCLE (PARENTAL ANIMALS)
- Oestrous cycles, pre-coital interval and mating performance and fertility were considered unaffected by treatment with Neryl Acetate, when compared with Controls.
- Two females receiving 2500 ppm had irregular cycles. One Control female and one female receiving 7500 ppm had a pre-coital interval of 13-16 days; all other animals had an interval of 1-4 days.

REPRODUCTIVE PERFORMANCE (PARENTAL ANIMALS)
- Gestation length was within the expected time frame 22-23 days for all animals; gestation length and gestation index were considered unaffected by treatment at any dose level.

ORGAN WEIGHTS (PARENTAL ANIMALS)
- Organ weights for males and toxicity phase females killed after 6 weeks of treatment indicated that the adjusted group mean kidney weights for animals that received 7500 ppm and the adjusted group mean liver weights for females that received 7500 ppm were slightly but statistically significantly higher than that of the Controls.
- Organ weights taken following the two week recovery period for animals that received 7500ppm, were similar to Controls indicating no persistent affects.
- Group mean unadjusted and adjusted organ weights for reproductive phase females killed on Day 7 of lactation were essentially similar to Controls, showing no adverse effects of treatment.

GROSS PATHOLOGY (PARENTAL ANIMALS)
- The macroscopic examination performed after the six weeks scheduled treatment period revealed no test substance related lesions. Macroscopic examination of reproductive female on Day 7 of lactation did not reveal any findings that could be attributed to treatment with test item.
The macroscopic examination performed after 2 weeks of recovery revealed no test substance related lesions. All findings were similar to the background of changes commonly seen in Sprague Dawley rats seen at these laboratories.

HISTOPATHOLOGY (PARENTAL ANIMALS)
- No treatment related changes were observed in rats up to 7500 ppm by dietary administration for five weeks.
- Seminiferous tubules were evaluated with respect to their stage in the spermatogenic cycle and the integrity of various cell types present within the different stages. No cell or stage specific abnormalities were noted.
- Minimal cortical tubular hypertrophy of kidney was observed in one male (4M No. 13) at 7500 ppm. This finding correlated with slight increase in the weight of kidneys. However, considering the single incidence in only one sex, its relationship to treatment is uncertain.
- An increase in the minimal multifocal aggregates of alveolar macrophages in the lung was observed in 4/5 females at 7500 ppm. One of the control females also had this finding. The aggregates of alveolar macrophages were mainly observed in the sub pleural locations or in the parenchyma away from terminal bronchioles, which are considered as common background finding in rats. The increase in the incidence in treated females alone is considered as incidental.

OTHER FINDINGS (PARENTAL ANIMALS)
Sensory reactivity and grip strength: There was no effect of test item on sensory reactivity or grip strength.
Motor activity: Motor activity was unaffected for females up to 7500 ppm, when compared to Controls and there were no clear effects on either rearing (high beam) or ambulatory (low beam) motor activity for males.
Haematology:
- Haematological examination during Week 6 of treatment revealed statistically significantly lower group mean erythrocyte counts in males receiving 7500 ppm, and a slight but not statistically significant lower level for males receiving 2500 or 1000 ppm when compared with Controls. Statistically significantly higher mean cell haemoglobin levels for males receiving 7500 ppm and slightly but statistically significant higher mean cell volume levels for males receiving 1000 ppm or above were observed. Mean cell haemoglobin concentration was slightly but statistically significantly higher for females receiving 1000 ppm or above. - Other inter-group differences from Controls were minor; neutrophil counts were higher for females receiving 7500 ppm when compared to Controls, but lacked a dose-relationship and was confined to one sex and was therefore considered due to normal biological variation.
- In Week 2 of recovery, haematological examinations of erythrocyte counts, mean cell haemoglobin and mean cell volume in males that received 7500 ppm and mean cell haemoglobin concentration, total leucocyte count and differential leucocyte count (neutrophils, lymphocytes, eosinophils, basophils, monocytes and large unstained cells) in females that received 7500 ppm were similar to that of the Controls.
Clinical chemistry:
- The biochemical examination of the blood plasma in Week 6 of treatment did not indicate any clear effects of treatment. When compared with the Controls, plasma levels of bile acids for males receiving 1000 ppm or above were slightly, but statistically significantly decreased, but no dose trend was apparent.
- All other inter-group differences from Controls were minor, were confined to one sex or lacked a dose-relationship. Such differences included minor, transient variations of some plasma electrolyte concentrations such as sodium levels in males and potassium levels in females receiving 7500 ppm; these values were considered fortuitous and were therefore considered of no toxicological importance.
- Review of bile acid levels in Week 2 of recovery revealed levels similar to Controls for males that received 7500 ppm. Group mean sodium levels in Week 2 of recovery were the same as Controls.

Key result

Dose descriptor:

NOAEL

Remarks:

systemic toxicity

Effect level:

7 500 ppm (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: No adverse effect observed up to the highest dose tested, corresponding to 440 mg/kg bw/day for males, 471-547 mg/kg bw/day during the gestation period and 624-1080 mg/kg bw/day during the lactation period for reproductive females.

Clinical signs:

no effects observed

Mortality / viability:

no mortality observed

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Group mean bodyweight on Days 1, 4 and 7 of age and mean bodyweight gain were lower in male (statistically significant lower bodyweight) and female (statistically significant lower bodyweight on Day 1 of age) offspring from parents treated at 7500 ppm when compared with Controls.
Male and female offspring bodyweights from parents that received 1000 or 2500 ppm were considered unaffected by treatment.

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Sexual maturation:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Histopathological findings:

no effects observed

Behaviour (functional findings):

not examined

Developmental immunotoxicity:

not examined

CLINICAL SIGNS (OFFSPRING)
There were no clinical signs observed for offspring that were considered related to treatment with test item.

LITTER SIZE, SURVIVAL INDICES AND SEX RATIO
- Litter size was not affected by treatment with test item. The number of females raising their litters to Day 7 of age was 9, 10, 10 and 10 for Control, 1000, 2500 and 7500 ppm respectively. One Control female (1F 100) was not pregnant.
- Group mean post implantation survival index, mean live birth index, and viability index were unaffected by treatment with test item.
- The mean percentage of males was statistically significantly higher than in Controls at 1000 or 7500 ppm but there was no dose response. No effect of treatment was inferred since the magnitude of difference from the ideal sex ratio of 50 % at 7500 ppm was similar to the magnitude of difference from 50 % in the Control group.

BODY WEIGHT (OFFSPRING)
- Group mean bodyweight on Days 1, 4 and 7 of age and mean bodyweight gain were lower in male (statistically significant lower bodyweight) and female (statistically significant lower bodyweight on Day 1 of age) offspring from parents treated at 7500 ppm when compared with Controls.
- Male and female offspring bodyweights from parents that received 1000 or 2500 ppm were considered unaffected by treatment.

GROSS PATHOLOGY (OFFSPRING)
Macroscopic examination of offspring that either died prematurely or at scheduled termination on Day 7 of age did not reveal any findings that could be attributed to treatment with test item.

Key result

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

7 500 ppm (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: No adverse effect observed up to the highest dose tested

Critical effects observed:

no

Key result

Reproductive effects observed:

no

Formulation analysis:

The mean concentrations were within applied limits of +10%/-15%, confirming the accuracy of formulation. The difference from mean values was <3 %, confirming precise analysis. Procedural recovery values remained within 94.2 and 100.8 %, confirming the continued accuracy of the method.

Achieved dose

Achieved intake of animals measured during the toxicity phase generally maintained the intended intervals between treatment groups. As anticipated, achieved intake was higher at the start of the treatment period and declined progressively as the animals matured.

Table 7.8.1/4: Achieved dosage for Toxicity and Recovery phase males

 

Level (ppm)	Achieved dosage (mg/kg bw/day)
	Mean	Range
1000	61	51-72
2500	150	129-175
7500	440	366-518

 

Table 7.8.1/5: Achieved dosage for Toxicity and Recovery phase females

 

Level (ppm)	Achieved dosage (mg/kg bw/day)
	Mean	Range
1000	65	55-71
2500	150	127-169
7500	465	436-495

Achieved intake of females measured throughout the treatment period, generally maintained the intended intervals between treatment groups. Achieved intake was relatively stable during gestation, but increased significantly during lactation, reflecting increasing food intake during this period of high physiological demand on the parent female.

Table 7.8.1/6: Achieved dosage for Reproductive phase females

 

Level (ppm)	Achieved dosage (mg/kg bw/day)
	Pre-pairing phase		Gestation	Lactation
	Average	Range	Range	Range
1000	67	63-70	65-80	98-151
2500	172	161-182	168-189	266-390
7500	484	483-484	471-547	624-1080

Conclusions:

The NOAEL for systemic and reproductive / developmental toxicity was 7500 ppm, corresponding to 440 mg/kg bw/day for males, 471-547 mg/kg bw/day during the gestation period and 624-1080 mg/kg bw/day during the lactation period for reproductive females.

Executive summary:

In a Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test conducted according to guideline OECD 422 and in compliance with GLP, groups of Crl:CD(SD) rats received NERYL ACETATE orally, via the diet, at concentrations of 1000, 2500 or 7500 ppm. Toxicity phase males were treated daily for three weeks before pairing, throughout pairing and up to necropsy after a minimum of five consecutive weeks. Toxicity phase females were treated daily for a minimum of five consecutive weeks up to necropsy in Week 6. Reproductive females were treated daily for three weeks before pairing, throughout pairing, gestation and until Day 6 of lactation. Five high dose Recovery phase male and female rats were treated daily for a minimum of five consecutive weeks, followed by a 14 day period without treatment. Recovery phase males were used for pairing with reproductive phase females, but recovery females were not paired. A similarly constituted Control group was assigned to each phase, and received the vehicle in untreated diet, throughout the same relative treatment period.

During the study, clinical condition, detailed physical and arena observations, sensory reactivity, grip strength, motor activity, body weight, food consumption, haematology, blood chemistry,oestrous cycles, pre-coital interval, mating performance, fertility, gestation length, organ weight and macroscopic investigations were undertaken for adult animals. Microscopic pathology investigations were undertaken for the first five Toxicity phase males and Reproductive and Toxicity phase females in Group 1 (Control) and Group 4 (7500 ppm). The clinical condition of offspring, litter size and survival, sex ratio and body weight were assessed, and macroscopic pathology investigations were undertaken. The F1 generation received no direct administration of the test substance; any exposure was in utero or via the milk.

The mean concentrations of the test item in formulations were within applied limits of +10%/-15%, confirming the accuracy of formulation. The difference from mean values was <3 %, confirming precise analysis. Procedural recovery values remained within 94.2 and 100.8 %, confirming the continued accuracy of the method.

Administration of the test item at dose levels of 1000, 2500 and 7500 ppm was well tolerated with no mortalities or effects that could be attributed to treatment on clinical condition, sensory reaction, grip strength, motor activity, oestrous cycles, macroscopic or microscopic pathology among the adult animals. In addition there were no effects on pre‑coital interval, mating performance, fertility, gestation length, offspring survival or development.

Mean achieved dosages during the pre-pairing phase were 61, 150 and 440 mg/kg bw/day for males and 65, 150 and 465 mg/kg bw/day for toxicity phase females and 67, 172 and 484 mg/kg/day for reproductive phase females receiving 1000, 2500 and 7500 ppm, respectively. For F0 females, the ranges of achieved dosages at 1000, 2500 and 7500 ppm were 65-80, 168-189 and 471-547 mg/kg bw/day during the gestation period and 98-151, 266-390 and 624-1080 mg/kg bw/day during the lactation period. 

Group mean bodyweight gain (Week 1 of treatment) was reduced in males receiving 7500 ppm and females receiving 1000, 2500 and 7500 ppm when compared with Controls; and overall bodyweight gain was statistically significantly lower than Controls in females, but a dose response was not apparent. Overall bodyweight change during the recovery period was slightly but not statistically significantly lower for males, but was significantly higher for females that had received 7500 ppm. Overall food consumption for males and toxicity phase females receiving NERYL ACETATE up to 7500 ppm was unaffected by treatment. Food intake was slightly lower on Day 1 of treatment for toxicity and reproductive females receiving 7500 ppm when compared with Controls. Group mean food consumption during early gestation was low for females receiving 2500 or 7500 ppm and during Days 2-5 of lactation for females receiving 7500 ppm, when compared with Controls.

Haematological examination during Week 6 of treatment revealed statistically significantly lower group mean erythrocyte counts in males receiving 7500 ppm, and a slight but not statistically significant lower level for males receiving 2500 or 1000 ppm when compared with Controls. Statistically significantly higher mean cell haemoglobin levels for males receiving 7500 ppm and slightly but statistically significant higher mean cell volume levels for males receiving 1000 ppm or above. Mean cell haemoglobin concentration was slightly but statistically significant higher for females receiving 1000 ppm or above. Haematological parameters examined in Week 2 of recovery were similar to that of the Controls.

The biochemical examination of the blood plasma in Week 6 of treatment did not indicate any clear effects of treatment. When compared with the Controls, plasma levels of bile acids for males receiving 1000 ppm or above were slightly, but statistically significantly decreased, but no dose trend was apparent. Review of bile acids levels in Week 2 of recovery revealed similar levels to Controls for males that received 7500 ppm.

Organ weights for males and toxicity phase females killed after 6 weeks of treatment indicated that the adjusted group mean kidney weights for animals that received 7500 ppm and the adjusted group mean liver weights for females that received 7500 ppm were slightly but statistically significantly higher than that of the Controls. Organ weights taken following the two week recovery period for animals that received 7500 ppm, were similar to Controls indicating no persistent effects. Group mean unadjusted and adjusted organ weights for reproductive phase females killed on Day 7 of lactation were essentially similar to Controls, showing no adverse effects of treatment.

Group mean offspring bodyweight on Days 1, 4 and 7 of age and mean bodyweight gain were slightly lower in male (statistically significant lower bodyweight) and female (statistically significant lower bodyweight on Day 1 of age), offspring from parents treated at 7500 ppm when compared with Controls, but their growth curves were essentially parallel to those of the Controls.

Therefore, the NOAEL for systemic and reproductive / developmental toxicity was 7500 ppm.

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

440 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

Recent GLP study conducted according to OECD Guideline No 422 without any deviation (Klimisch score = 1).

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

In a Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test conducted according to guideline OECD 422 and in compliance with GLP, groups of Crl:CD(SD) ratsreceived NERYL ACETATEorally, via the diet, at concentrations of 1000, 2500 or7500 ppm.Toxicity phase males weretreated dailyfor three weeks before pairing, throughout pairing and up to necropsy after a minimumof five consecutive weeks. Toxicity phase femaleswere treateddaily for a minimumof five consecutive weeksup to necropsy in Week 6.Reproductivefemales were treated daily for three weeks before pairing, throughoutpairing, gestation and until Day6of lactation.Five high dose Recovery phase male and female rats were treated daily for a minimumof five consecutive weeks, followed by a 14 day period without treatment. Recovery phase males were used for pairing with reproductive phase females, but recovery females were not paired.A similarly constituted Control group was assigned to each phase, and received the vehicle in untreated diet, throughout the same relative treatment period.

During the study, clinical condition,detailed physical and arena observations, sensory reactivity, grip strength, motor activity, body weight, food consumption, haematology, blood chemistry,oestrous cycles, pre-coital interval, mating performance,fertility,gestation length, organ weight and macroscopic investigationswere undertaken for adult animals. Microscopicpathology investigations were undertakenforthefirst five Toxicity phase males and Reproductive and Toxicity phase females inGroup 1 (Control) andGroup4 (7500 ppm). Theclinical condition of offspring, litter size and survival, sex ratio and body weight were assessed,and macroscopic pathology investigations were undertaken. The F1 generation received no direct administration of the test substance; any exposure wasin uteroor via the milk.

Administration of the test item at dose levels of 1000, 2500 and 7500 ppm was well tolerated with no mortalities or effects that could be attributed to treatment on clinical condition, sensory reaction, grip strength, motor activity, oestrous cycles, macroscopic or microscopic pathology among the adult animals. In addition there were no effects on pre‑coital interval, mating performance, fertility, gestation length, offspring survival or development.

Group mean bodyweight gain (Week 1 of treatment) was reduced in males receiving 7500 ppm and females receiving 1000, 2500 and 7500 ppm when compared with Controls; and overall bodyweight gain was statistically significantly lower than Controls in females, but a dose response was not apparent. Overall bodyweight change during the recovery period was slightly but not statistically significantly lower for males, but was significantly higher for females that had received 7500 ppm.Overall food consumption for males and toxicity phase females receiving NERYL ACETATE up to 7500 ppm was unaffected by treatment. Food intake was slightly lower on Day 1 of treatment for toxicity and reproductive females receiving 7500 ppm when compared with Controls.Group mean food consumption during early gestation was low for females receiving 2500 or 7500 ppm and during Days 2-5 of lactation for females receiving 7500 ppm, when compared with Controls.

Haematological examination during Week 6 of treatment revealed statistically significantly lower group mean erythrocyte counts in males receiving 7500 ppm, and a slight but not statistically significant lower level for males receiving 2500 or 1000 ppm when compared with Controls. Statistically significantly higher mean cell haemoglobin levels for males receiving 7500 ppm and slightly but statistically significant higher mean cell volume levels for males receiving 1000 ppm or above. Mean cell haemoglobin concentration was slightly but statistically significant higher for females receiving 1000 ppm or above. Haematological parameters examined in Week 2 of recovery were similar to that of the Controls.

The biochemical examination of the blood plasma in Week 6 of treatment did not indicate any clear effects of treatment. When compared with the Controls, plasma levels of bile acids for males receiving 1000 ppm or above were slightly, but statistically significantly decreased, but no dose trend was apparent. Review of bile acids levels in Week 2 of recovery revealedsimilar levels to Controlsfor males that received 7500 ppm.

Organ weights for males and toxicity phase females killed after 6 weeks of treatment indicated that the adjusted group mean kidney weights for animals that received 7500 ppm and the adjusted group mean liver weights for females that received 7500 ppm were slightly but statistically significantly higher than that of the Controls. Organ weights taken following the two week recovery period for animals that received 7500 ppm, were similar to Controls indicating no persistent effects. Group mean unadjusted and adjusted organ weights for reproductive phase females killed on Day 7 of lactation were essentially similar to Controls, showing no adverse effects of treatment.

Group mean offspring bodyweight on Days 1, 4 and 7 of age and mean bodyweight gain were slightly lower in male (statistically significant lower bodyweight) and female (statistically significant lower bodyweight on Day 1 of age), offspring from parents treated at 7500 ppm when compared with Controls, but their growth curves were essentially parallel to those of the Controls.

Effects on developmental toxicity

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no study available

Justification for classification or non-classification

No toxic effects were observed in a repeated dose toxicity study combined with a reproduction/developmental toxicity screening

until the highest dose tested, corresponding to 440 mg/kg bw/day for males, 471 -547 mg/kg bw/day during the gestation period and 624 -1080 mg/kg

bw/day during the lactation period for reproductive females.

Therefore NERYL ACETATE is not classified for reproduction toxicity according to CLP Regulation (EC) No 1272 /2008.