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Administrative data

Description of key information

NOAEL (OECD 408, oral, rat): ≥ 1000 mg/kg bw/day

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records
Reference
Endpoint:
sub-chronic toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: GLP guideline study with acceptable restriction. Purity not reported.
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity in Rodents)
Deviations:
yes
Remarks:
Guideline not stated, purity not reported.
Qualifier:
according to
Guideline:
other: Commission of the European Communities CS/PM/2024, 2 April 1993
GLP compliance:
yes
Limit test:
no
Species:
rat
Strain:
other: Crl: CD(SD)BR (VAF plus)
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River (UK) Limited, Margate, England
- Age at study initiation: 5 to 6 weeks
- Weight at study initiation: males 141-176 g, females 112-148 g
- Fasting period before study: not applicable, feeding study
- Housing: groups of 5 by sex, in grid-bottomed stainless steel cages (Modular Systems, Kent, England), suspended over paper-lined trays
- Diet (e.g. ad libitum): Powdered diet (SQC Rat and Mouse Maintenance Diet No. 1, Ground Fine, Special Diets Services Limited, Witham, England), ad libitum (except for those periods of deprivation associated with laboratory investigations).
- Water (e.g. ad libitum): Mains water provided in polypropylene bottles, ad libitum (except for those periods of deprivation associated with laboratory investigations).
- Acclimation period: 12 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18-25
- Humidity (%): 28-48
- Air changes (per hr): air conditioned, not further specified
- Photoperiod (hrs dark / hrs light): 12/12
Route of administration:
oral: feed
Vehicle:
unchanged (no vehicle)
Details on oral exposure:
DIET PREPARATION
- Rate of preparation of diet (frequency): Diet mixes were formulated weekly.
- Mixing appropriate amounts with (Type of food): Powdered diet (SQC Rat and Mouse Maintenance diet No. 1, Ground Fine, Special Diets Services, Witham, England). A pre-mix was prepared at an appropriate concentration by mixing a weighed amount of test article with a small quantity of diet. This was then mixed with more diet in a rotary mixer and made up to a final quantity with the remaining blank diet in a double-cone blender. To prepare formulated diets appropriate quantities of the pre-mix were mixed with blank diet to make up to the final quantity in a double-cone blender. Formulated diets for males and females were mixed separately.
- Storage temperature of food: not reported
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
To determine the achieved concentration, samples of each diet (including that for the control group), prepared for weeks 1 and 13, were analysed for test article by the Sponsor using a previously validated method. The results are reported separately by the Sponsor.
The stability and homogeneity of test article diets prepared over the concentration ranges used on this study have been assessed by the Sponsor, as well, using the previously validated method.

The achieved dose levels were within 3% of nominal. All individual group values were within 15% of nominal.
Duration of treatment / exposure:
13 weeks
Frequency of treatment:
continuously in diet
Remarks:
Doses / Concentrations:
250, 500, 1000 mg/kg bw/day
Basis:
nominal in diet
No. of animals per sex per dose:
10
Control animals:
yes, plain diet
Details on study design:
- Dose selection rationale: Dose levels were selected by the Sponsor after examining preliminary work performed by Quintiles (Quintiles Study Number: CRC/01/C).
Positive control:
none
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Twice daily for mortality and morbidity, once daily for clinical signs; if required by clinical condition of an animal, monitoring was adjusted accordingly.
- Cage side observations included: Mortality, morbidity, clinical signs.

BODY WEIGHT: Yes
- Time schedule for examinations: On the day prior to dosing and then weekly thereafter.

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

OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: Two days prior to dosing and on Day 85.
- Dose groups that were examined: All animals before dosing, and control and high dose group on Day 85

HAEMATOLOGY: Yes
- Time schedule for collection of blood: Week 13
- Anaesthetic used for blood collection: No, blood was taken via tail vein puncture
- Animals fasted: Yes, overnight
- How many animals: All animals
- Parameters examined (in blood taken into EDTA anticoagulant): Erythrocyte count, hemoglobin concentration, leukocyte differential count, mean cell hemoglobin, mean cell hemoglobin concentration, mean cell volume, packed cell volume, platelet count, total leukocyte count.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: Week 13
- Animals fasted: Yes, overnight
- How many animals: All animals
- Parameters examined (in blood taken into lithium heparin anticoagulant): A/G ratio, alanine aminotransferase, albumin, alkaline phosphatase, aspartate aminotransferase, blood urea nitrogen, calcium, chloride, cholesterol, creatinine, glucose, phosphorus, potassium, sodium, total bilirubin, total protein. Coagulation tests (on blood taken into 3.2% aqueous trisodium citrate anticoagulant): activated partial thromboplastin time, fibrinogen, prothrombin time.

URINALYSIS: Yes
- Time schedule for collection of urine: Week 13
- Metabolism cages used for collection of urine: No data
- Animals fasted: Yes, overnight
- Parameters examined: Bilirubin, blood pigments, glucose, ketones, leukocytes, microscopic examination of sedimented deposit, nitrites, pH, protein, specific gravity, urobilinogen, volume.
Sacrifice and pathology:
GROSS PATHOLOGY: Yes; all animals were killed by CO2 asphyxiation, weighed and examined externally. The animals were then exsanguinated. The cranial, thoracic and abdominal cavities were opened and examined macroscopically. Any abnormalities were recorded with details of the location, colour, shape and size.

HISTOPATHOLOGY: Yes; with the exception of the eyes, optic nerves and testes, either whole organs or samples of the following tissues were preserved in neutral buffered formaldehyde. The eyes and optic nerves were fixed in Davidson's fluid and the testes were fixed in Bouin's fixative for 24 hours and then transferred to neutral buffered formaldehyde. Organs examined: adrenals, aorta, brain (3 sections), caecum, colon, duodenum, epididymides, eyes (incl. optic nerves), femur (incl. marrow) and joint, heart, ileum, jejunum, kidneys, liver, lungs (incl. mainstem bronchi), mesenteric lymph node, oesophagus, ovaries, pancreas, pituitary, prostate, rectum, salivary gland, sciatic nerve, seminal vesicles, site of mammary gland, skeletal muscle, skin, spinal cord (3 levels), spleen, sternum, stomach, submandibular lymph node, testes, thymus, thyroids, (incl. parathyroids), trachea, urinary bladder, uterus, vagina, all gross lesions. The aforementioned organs were examined from control and high dose animals and from all animals deceased or killed during the study; lungs and all gross lesions were examined from all animals. If target organs were identified in high dose animals they were examined in low and intermediate dose animals, as well.
Other examinations:
ORGAN WEIGHTS
Absolute and relative organ weights from all animals: adrenals, brain, heart, kidneys, liver, ovaries, pituitary, spleen, testes, thymus, thyroids; contralateral organs were weighed together.
Statistics:
Group means and standard deviations were calculated where appropriate. No analysis will be performed for variable for which the control group has less than 5 independent observations per group. In situations where the treated groups have fewer than 5 observations comparisons will be performed at the discretion of the statistician. Sexes will be analysed separately. If combination of sexes is required for a particular analysis (for example because of small group sizes), then the analysis will be adjusted for sex differences as well as treatment group, and a test performed for a sex by treatment interaction. Such an analysis will be supported by scientific or statistical rationale. The data will be examined prior to analysis for any obvious outlying observations, which will be excluded from the analysis, any obvious skew in the distribution, for which the data will be log transformed prior to analysis and also for a high incidence of tied data. If the proportion of ties in a data set exceeds 30% then the non-parametric methods outlined below will be deemed unsuitable. Any adhoc comparisons performed, other than those described below, will be performed using a suitable conservative comparison procedure.
Clinical signs:
effects observed, treatment-related
Description (incidence and severity):
unrelated to treatment
Mortality:
mortality observed, treatment-related
Description (incidence):
unrelated to treatment
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
unrelated to treatment
Food consumption and compound intake (if feeding study):
no effects observed
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
no effects observed
Haematological findings:
effects observed, treatment-related
Description (incidence and severity):
not toxicologically significant
Clinical biochemistry findings:
effects observed, treatment-related
Description (incidence and severity):
not toxicologically significant
Urinalysis findings:
effects observed, treatment-related
Description (incidence and severity):
unrelated to treatment
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Description (incidence and severity):
not toxicologically significant
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Description (incidence and severity):
unrelated to treatment
Histopathological findings: neoplastic:
no effects observed
Details on results:
CLINICAL SIGNS AND MORTALITY
Hairloss was noted in the treated animals, which is a common finding in animals of this strain and age and lacked any dose-relationship.

One mid dose female was killed in extremis on day 50, clinical signs included peribuccal swelling, teeth abnormalities and black periorbital staining. Histopathology revealed peribuccal ulceration. In view of the isolated nature of this finding it was considered to be unrelated to treatment.

BODY WEIGHT AND WEIGHT GAIN
Bodyweight and bodyweight gains were considered to be unaffected by treatment. Body weight gains were slightly reduced in all treated male groups, however these values were within 8% of controls and therefore considered not to be an effect of treatment. Female groups showed bodyweight gains within 3% of controls. The slight bodyweight loss noted in week 13 of the study was considered to be attributable to blood sampling procedures.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
Food consumption was unaffected by treatment and was similar in all groups.

OPHTHALMOSCOPIC EXAMINATION
There were no treatment-related findings at ophthalmoscopic examination.

HAEMATOLOGY
A non-dose-related increase in monocytes was apparent in all treated male groups. Group mean values for the low and the mid dose groups were within the expected background ranges. However, 5/10 males of the high dose group exceeded the normal range. Due to the small magnitude of this change and in the absence of any related pathological changes, this was considered to be without toxicological significance.

All treated females showed reduced activated partial thromboplastin times compared to controls; however, this was considered to be due to two animals in the control group having high values and not to any effect of the test substance.

CLINICAL CHEMISTRY
There were no changes considered to be of toxicological significance. The statistically significant values noted in several parameters (creatinine, albumin) were minor, and all group mean values were within the normal ranges found in this laboratory.

URINALYSIS
There were no changes attributable to treatment. The trace and small amounts of epithelial cells and casts noted were apparent throughout the dose groups, and in the absence of any supporting pathology this was considered to be unrelated to the test substance.

ORGAN WEIGHTS
A statistically significant reduction in absolute liver weights was observed in all treated male groups, and a statistically significant reduction in bodyweight-related liver weights was observed in males of the mid and high dose group. In the absence of corresponding histopathological findings this was considered not to be of toxicological significance.

A statistically significant reduction in absolute brain weight was apparent in all treated males. However, there was no effect on bodyweight-related brain weights, and therefore this finding was considered to be unrelated to treatment.

Body weight-related heart weights were statistically higher than in controls in all treated female groups. As this change was minor and lacked a dose-related manner, it was considered not to be of any toxicological significance.

GROSS PATHOLOGY
There were no treatment-related macroscopic findings.

HISTOPATHOLOGY: NON-NEOPLASTIC
There were no treatment-related microscopic findings. The small number of histopathological findings recorded were within the normal range of background alterations which may be seen in untreated rats of this age and strain.

HISTOPATHOLOGY: NEOPLASTIC (if applicable)
There were no neoplastic findings reported.
Dose descriptor:
NOAEL
Effect level:
>= 1 000 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: No adverse effects observed up to the highest dose tested.
Critical effects observed:
not specified

Conclusion:

The repeated daily administration of the test substancein the diet to the Crl:CD(SD)BR(VAF plus) strain for 13 weeks at dose levels of 250, 500 and 1000 mg/kg bw/day did not reveal any evidence of toxicity. Therefore, the NOAEL was determined to be 1000 mg/kg bw/day.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEL
1 000 mg/kg bw/day
Study duration:
subchronic
Species:
rat
Quality of whole database:
The available information comprises adequate, reliable (Klimisch score 1-2) and consistent studies, and is thus sufficient to fulfil the standard information requirements set out in Annex VIII-IX, 8.6, of Regulation (EC) No 1907/2006.

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

Oral

Subacute

There is one study available on the subacute oral toxicity of (Z)-N-octadecyldocos-13-enamide (CAS 10094-45-8) in female Holtzman rats via oral gavage, which was not performed according to a specific test guideline (Levenstein, 1963). During 5 consecutive days, 10 animals were daily administered the test substance in olive oil in 2 dose intervals of 5 mL total volume per gavage, amounting for a daily total dose of approx. 5000 mg/kg bw/day. During the treatment and a subsequent 20-day post-exposure recovery period, no mortalities and clinical signs of toxicity were noted. The animals showed a normal body weight gain during the entire study period. At sacrifice, no gross pathological abnormalities were noted in any of the treated animals. Based on the results of this study, the NOEL of the test substance in female rats was considered to be ca. 5000 mg/kg bw/day.

Subchronic

The subchronic oral toxicity of (Z)-N-octadecyldocos-13-enamide (CAS 10094-45-8) was investigated in male and female Crl: CD(SD)BR (VAF plus) rats in a GLP-conform study according to the requirements of the Commission of the European Communities CS/PM/2024 (2 April 1993) and similar to OECD 408 (Brownlie, 1998). Based on a preliminary dose-range finding study, the test substance was administered continuously for a period of 13 weeks to groups of 10 animals per sex at dietary dose levels of 250, 500 and 1000 mg/kg bw/day, respectively. A similar constituted control group received the plain diet. On Day 50 of the study, one female from the 500 mg/kg bw/day dose group was killed in extremis due to clinical signs including peribuccal swelling, teeth abnormalities and black periorbital staining. Histopathology of this animal revealed peribuccal ulceration, which in view of the isolated nature of this finding was considered to be unrelated to treatment. In treated animals, hair loss was noted among all dose groups, which, in the absence of any dose-response relationship, was not considered to be treatment-related, since it was reported to be a common finding in animals of this strain and age. Body weights as well as food and water consumption in treated animals were not significantly altered compared to those of controls. At the terminal ophthalmoscopic examination, no adverse findings on eyes attributable to treatment were noted. Clinical chemistry analysis revealed sporadic differences in some parameters which were not dose-related and within the normal range of control values, and thus not toxicologically relevant. At haematological analysis, a non-dose-related increase in monocytes was apparent in males of all treatment groups. However, group mean values for animals treated with 250 and 500 mg/kg bw/day were within the expected background ranges of the controls. Only in 5/10 males of the high dose group the normal range in the number of monocytes was exceeded, but this change was considered to be without toxicological significance due to the small magnitude and in the absence of any corresponding pathological changes. In urine, trace and small amounts of epithelial cells and casts were apparent throughout the dose groups, but in the absence of any supporting pathology this was considered to be unrelated to the test substance. Determination of organ weights revealed a statistically significant reduction in absolute liver weights in males of all treatment groups, whereas a statistically significant decrease in relative liver weights was only noted in males of the 500 and 1000 mg/kg bw/day dose group. In the absence of any corresponding histopathological findings, the changes in liver weight were considered to be non-adverse, and thus of no toxicological significance. All other statistically significant effects on organ weights (brain and heart) were not considered to be treatment-related, as they occurred in the absence of any histopathological findings, and were thus considered to be of no toxicological relevance. Gross necropsy and histopathological (neoplastic and non-neoplastic) examination, including male and female reproduction organs, did not reveal any pathological findings related to treatment with the test substance. Based on the overall effects of the study, a NOAEL of ≥ 1000 mg/kg bw/day for male and female rats was derived.


Justification for selection of repeated dose toxicity via oral route - systemic effects endpoint:
The selected study is the most adequate and reliable study with the longest duration and the lowest dose descriptor.

Justification for classification or non-classification

The available data on repeated dose toxicity of (Z)-N-octadecyldocos-13-enamide (CAS 10094-45-8) via the oral route do not meet the criteria for classification according to Regulation (EC) No 1272/2008 or Directive 67/548/EEC and are therefore conclusive but not sufficient for classification.