Octadecene, reaction products with hexadecene, hydrogenated

Basic toxicokinetics

Administrative data

Endpoint:

basic toxicokinetics in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

28 November 2022 to 18 December 2022

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2023

Report date:

2023

Materials and methods

Objective of study:

absorption

distribution

excretion

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 417 (Toxicokinetics)

Version / remarks:

OECD Guidelines for Testing of Chemicals (No. 417, Toxicokinetics, Adopted: 22 July 2010)

Deviations:

yes

Remarks:

See "Any other information" for details

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Oligomerisation products of alpha-alkenes C16-18 (even numbered), hydrogenated, hydroisomerised

EC Number:

832-827-5

Cas Number:

2241366-04-9

Molecular formula:

Variable - UVCB

IUPAC Name:

Oligomerisation products of alpha-alkenes C16-18 (even numbered), hydrogenated, hydroisomerised

Test material form:

liquid

Details on test material:

Name: SynNova Base Oil
CAS number: 2241366-04-9
Batch/Lot number: TS20371/TS21270
Description: Liquid - water white colorless oil.
Purity: 100%
Expiry date: 25 February 2021/31 July 2021
Storage conditions: Controlled room temperature (15-25°C, ≤70% relative humidity)
Safety precautions: Routine safety precautions (gloves, goggles, face mask, lab coat) for unknown materials were applied to ensure personnel health and safety.

Specific details on test material used for the study:

No further details specified in the study report.

Radiolabelling:

no

Test animals

Species:

rat

Strain:

Wistar

Details on species / strain selection:

The Wistar rat as a rodent is one of the standard strains for toxicity studies.

Sex:

male

Details on test animals or test system and environmental conditions:

Species and strain: Han:WIST rats
Source: Toxi-Coop Zrt., H-1122 Budapest, Magyar Jakobinusok tere 4B
Hygienic level at supplier: SPF
Hygienic level during the study: Standard housing conditions
Number of groups: 2 groups, a control group treated with aqua purificata, and a test item treated group.
Number of animals: 8 male rats, 4 per dose group
Age of animals at start: Young adult rats, 8 - 9 weeks old
Body weight at the start: Did not exceed ± 20% of the mean weight at onset of treatment and were in the range of 265-287 g
Acclimatisation period: 17 days

Husbandry
Animal health: Only healthy animals were used for the test. The health status was certified by the Veterinarian.
Cage type: T3H polycarbonate
Housing / Enrichment: The animals were housed individually. During other than sampling periods, “SAFE 3/4-S-FASERN” certified wooden chips (batch number: 03027220608, expiry date: 08 June 2025 and 03027220329, expiry date: 29 March 2025) produced by J. Rettenmaier & Söhne GmbH & Co.KG (Holzmühle 1, D-73494 Rosenberg, Germany) and “Sizzle nest” nest material (batch number: SIZNEST00022W, expiry date: 05 August 2023) produced by LBS (Serving Biotechnology) Ltd. (Unit 20, Gatwick Business Park, Kennel Lane, Hookwood, Surrey, RH6 0AH, United Kingdom) were available to animals during the study. Copies of the Certificates of Analyses are archived with the raw data. During the urine and faeces collection periods, animals were kept in metabolic cages without bedding and nesting material, transformed with a special setting from their original type of cages. A standard T3H cage was equipped with a double-layer metal grid floor (with a stainless-steel mesh in-between), allowing the secure separation and collection of faeces and urine.
Lighting period: 12 hours daily, from 6.00 a.m. to 6.00 p.m.
Temperature: 20 – 24 °C (target: 22 ± 3 °C)
Relative humidity: 39 – 67 % (target: 30-70%)
Ventilation: 15-20 air exchanges/hour
The minimum and maximum temperature and relative humidity values were recorded daily during the study.

Food and water Supply
Animals received standard laboratory rat diet, ad libitum. The food is not considered to contain any contaminants that could reasonably be expected to affect the purpose or integrity of the study. The supplier provided an analytical certificate for the batch used, which is archived with the raw data.

Details of the diet used in the study were as follows:
Name: SM Rat/Mouse, Zucht + Haltung Ungarn, 15 mm / SM Rat/Mouse, Zucht + Haltung Ungarn, 10 mm, autoclavable
Manufacturer: ssniff Spezialdiäten GmbH (D-59494 Soest, Germany)
Batch number: 888 93498/101 95793
Expiry date: 28 February 2023 / 30 April 2023

Animals received tap water from the municipal supply, as for human consumption, from drinking bottles, ad libitum. Water quality control analysis and microbiological assessment are performed once per year by the laboratory of Veszprém County Government Office, Department of Public Health (Veszprém Megyei Kormányhivatal Népegészségügyi Főosztály, H-8200 Veszprém, József A. u. 36., Hungary). The quality control results are retained in the archives of NEXTREAT Laboratories.

Animal identification
Each animal were individually identified by unique numbers written on the tail with an indelible pen. The numbers were given on the basis of NEXTREAT Laboratories' master file, for each animal allocated to the study.
During the acclimation period, animals were identified by the master file numbers. After this period, a randomisation was performed based on the body weights and the selected animals received their final animal numbers, as follows:
The animal number consists of 4 digits, the first digit being the group number, and the last the animal number within the group.
The boxes were marked by identity cards, with information at least about study code, sex, dose group, cage number and individual animal numbers.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on exposure:

The test item was administered as supplied by the Sponsor, without using any vehicle.

Justification of the doses and route of administration
The dose levels were selected by the Sponsor in consultation with the Study Director, based on the results from an OECD 408, 90 days toxicity study with the aim of applying the highest non-toxic dose which may allow the identification of the test item from the urine, faeces and organs. The selected doses were the highest possible (limit) doses both in the acute and sub-acute phase of the study.
The oral route was selected as it is one of the possible routes of human exposure.

Duration and frequency of treatment / exposure:

Phase 1: a 2000 mg/kg bw single oral dose of the test item was administered to the animals by oral gavage
Phase 2: animals were administered by oral gavage for 14 consecutive days at the dose level of 1000 mg/kg bw

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

1 000 mg/kg bw/day (nominal)

Remarks:

Phase 2

Doses / concentrations 2

Dose / conc.:

2 000 mg/kg bw/day (nominal)

Remarks:

Phase 1

No. of animals per sex per dose / concentration:

4 males per group

Control animals:

yes, sham-exposed

Positive control reference chemical:

Not required for this study design.

Details on study design:

The dose levels were selected by the Sponsor in consultation with the Study Director, based on the results from an OECD 408, 90 days toxicity study with the aim of applying the highest non-toxic dose which may allow the identification of the test item from the urine, faeces and organs. The selected doses were the highest possible (limit) doses both in the acute and sub-acute phase of the study.

The oral route was selected as it is one of the possible routes of human exposure.

Details on dosing and sampling:

Dosing Procedure
Phase 1 (Day 0P1 followed by a 72 hours collection period):
Following an acclimation period of at least seventeen days, a 2’000 mg/kg bw single oral dose of the test item was administered to the animals by oral gavage, using a tipped gavage needle attached to a syringe. The first day of dosing of each animal was regarded as Day 0P1.A constant dose volume of 2.43 mL/kg bw was administered to all animals (calculated on the basis of the density of the test item). The actual volume administered was calculated and adjusted based on each animal’s most recent body weight.

Phase 2:
Following the last day of Phase 1, the animals were allowed to have a 3 days wash-out period, without any treatment. In phase two, animals were administered by oral gavage for 14 consecutive days at the dose level of 1’000 mg/kg bw in the same manner as detailed in the description of Phase 1, except that the administered dose volume was 1.22 ml/kg bw. The first day of dosing of each animal was regarded as Day 0P2.

IN-LIFE PROCEDURES
Clinical observations
Animals were inspected for signs of morbidity and mortality twice daily (at the beginning and end of each working day).
General clinical observations were made daily. Detailed clinical observations were made on all animals outside the home cage in a standard arena at the start of the pre-exposure, prior to the first dosing (Day 0P1, to allow for within-subject comparisons) and at least weekly thereafter, in the morning hours. Observation was performed on the skin, fur, eyes and mucous membranes, occurrence of secretions and excretions, autonomic activity (lacrimation, piloerection, pupil size, unusual respiratory pattern), circulatory and central nervous system (tremor, convulsion, muscular contractions, etc.), somatomotor activity and behaviour pattern (changes in exploratory behaviour, ordinary behaviour including changes in grooming, headshaking, gyration, etc., abnormal behaviour such as autophagia/self-mutilation, backward motion, abnormal vocalization, aggression, etc.), motor coordination, ambulatory abnormalities, changes in body position and posture (hunchback posture, etc.), gait, posture and response to handling and to environmental stimulation. Particular attention was directed to observation of tremors, convulsions, salivation, diarrhoea, lethargy, sleep and coma.

Body weight
Body weights of all animals were recorded with a precision of 1 g on the first and last day of the acute phase (Day 0P1 and Day 3P1), on the last day of wash out period, and weekly in the repeated dose phase (Day 0P2, Day 7P2 and on Day 14P2, prior to the scheduled necropsy).

Food consumption
The determination of food consumption was performed identically to the schedule of the body weight measurement. Daily food consumption was calculated.as the difference between the provided and the remaining, non-consumed food, both weighed with a precision of 1 g.

Urine and faeces collection
Phase 1:
Urine and faeces of the animals were collected in metabolic cages following the administration of the single dose, for 72 hours. The whole amount of excreta was taken in five fractions as follows:
• 0-6 hours post treatment
• 6-12 hours post treatment
• 12-24 hours post treatment
• 24-48 hours post treatment
• 48-72 hours post treatment

Phase 2:
Urine and faeces were collected as listed below:
• Day 0P2: 0-24 hours
• Day 6P2: 0-24 hours
• Day 13P2: 0-24 hours

The cage and all relevant surfaces of the metabolic cage were rinsed with the extractant used for the analysis of the test item (hexane). Volumes of collected urine and rinsing fluid, and weights of collected faeces were measured and recorded, and then transferred into suitable vessels. Vessels were labelled with the study code, the name of the matrix, and date and time of collection, and were stored at -20°C until analysis.

TERMINAL PROCEDURES
Terminal procedures
Necropsy and macroscopic examination was performed on all surviving animals, at the end of Phase 2 (Day 14P2). The animals were euthanized by exsanguination under pentobarbital anaesthesia. After the exsanguination, the following tissues/organs were separated (gloves were changed, and instruments were cleaned or changed between tissue samples):

• gastrointestinal tract from oesophagus to the rectum
• brain
• liver
• spleen

Tissue samples were weighed and taken into proper storage equipment, labelled with the study code, name and weight of the matrix, and date of collection stored frozen (approximately -20°C) until extraction.

Macroscopic examination
After exsanguinations, the external appearance was examined, all orifices, and the cranial, thoracic and abdominal cavities were opened and the appearance of the tissues and organs was observed macroscopically. Any abnormality was recorded with details of the location, colour, shape and size, as appropriate.

COLLECTION AND ANALYSIS OF SAMPLES
From each animal, individual samples were collected and these were treated as separate samples throughout the analytical procedure. All samples were weighed to the nearest of 1 mg.
The bioanalytical method has been validated in a GLP study at the Test Facility under study code N21001-927. Samples were subjected to a multi-step sample preparation procedure (including sample clean-up) followed by GC-FID analysis.

Collection, homogenization and storage of samples
At each sample collection time, faeces samples were collected from the animal cages, followed by the collection of urine. The cages were washed thoroughly with hexane which is then used for the extraction of the test item from the urine samples. Urine samples were processed immediately after collection.
The organs (spleen, brain, liver and gastrointestinal tract) were collected at the end of the study.

Samples other than urine were homogenized, and divided into two aliquots:
- back-up sample: an adequate portion of the homogenized sample was stored in freezer. The quantity of the back-up sample was chosen so that the test item analysis could be performed with this back-up sample in case of any potential discrepancies during the analysis of the sample.
- analysis sample: the remaining portion of the homogenized sample was subjected to sample preparation and analysis either immediately after collection or after storage at -20°C (as appropriate based on stability data observed during the bioanalytical method validation study)

Sample preparation
Samples were extracted with hexane followed by sample clean-up with 1/1 mixture of Florisil and diatomaceous earth adsorbent. The appropriate sample cleanup procedure was selected during a non-GLP bioanalytical method development study (N21001-927P), where the 1/1 mixture of Florisil and diatomaceous earth was proven not to adsorb the test item and remove it from the test media.

GC-FID analysis of the samples
Matrix-matched, internal standard calibration were applied with a minimum of 6 non-zero calibration solutions. Calibration curve was obtained by linear regression with weighting.
Together with the study samples, fresh recovery samples were prepared and analysed in order to follow daily measurement accuracy.
The results are given as mg (or µg) test item in 1 g of the sample (mg/g sample).

Statistics:

Not specified in the study report

Results and discussion

Main ADME results

Main ADME results 1

Type:

excretion

Results:

The near to complete amount (ca. 100%) of the applied test item was recovered from the stool of the animals.

Main ADME results 2

Type:

distribution

Results:

No test item could be detected in any of the organs analyzed in this study (gut, brain, liver, and spleen) under the conditions detailed in this report.

Main ADME results 3

Type:

absorption

Results:

No test item could be detected in any of the organs analyzed in this study (gut, brain, liver, and spleen) under the conditions detailed in this report.

Toxicokinetic / pharmacokinetic studies

Details on absorption:

No test item could be detected in any of the organs analyzed in this study (gut, brain, liver, and spleen) under the conditions detailed in this report.

Details on distribution in tissues:

No test item could be detected in any of the organs analyzed in this study (gut, brain, liver, and spleen) under the conditions detailed in this report. This corresponds with the results of the faeces analysis, so that the test item is not available for the organs, but remains in the gut and practically the whole amount is excreted with the faeces.

Transfer into organs

Key result

Observation:

no transfer detectable

Details on excretion:

Practically the total amount of the administered test item (ca. 100%) was recovered from the faeces, within 48 hours post-treatment. A negligible amount (In the urine, traces (less than 0.1% of the administered dose) of the test item were observed in case of animal Nr. 2001 in the samples collected from 0 to 24 hours post-treatment, and in case of animal Nr. 2004 in the sample collected from 0 to 6 hours post treatment.
The likely reason for the random appearance of test item traces in the urine is the contamination of the animal itself, and its urine by the faeces in situ in the metabolic cages, facilitated by the grooming activity of the animals. Oily compounds could be presented in the urine in case of pathological conditions such us renal injury, ketosis, dehydration or chyluria. None of these conditions were observed in this study, or in other repeated dose studies performed in the Test Facility with the same test item, therefore the internal origin of the test item in the urine is excluded.
Repeated dosage of the test item did not change the kinetic characteristics of the test item shown during the acute phase of the study. The near to complete amount of the applied test item could be recovered from the stool of the animals within 24 hours. Similarly to the acute phase, traces of the test item in the urine were found (less than 0.1% of the administered dose). For the same reason as detailed above (Acute Phase), internal origin of the test item in the urine is excluded.

Metabolite characterisation studies

Metabolites identified:

no

Remarks:

100% of substance was excreted without metabolisation.

Any other information on results incl. tables

RESULTS

Mortality

There was no mortality during the study.

 

Clinical observations

No clinical signs were observed in the study.

 

Body weight and body weight gain

The body weight or body weight gain of the animals developed as expected in this age and strain of animals, not test item related effects were noted when compared with the control.

 

Food consumption

No effect was noted on the food consumption of the animals.

Applicant's summary and conclusion

Conclusions:

In summary, acute, oral gavage administration of SynNova® Base Oil to male Hannover Wistar rats at the dose level of 2000mg/kg bw, followed by a 3 days washout period and subsequent daily oral gavage administration for 14 days at a dose level of 1000 mg/kg bw/day did not result in any mortality or clinical signs under the conditions of this study.

There was no test item-related effect in body weight, body weight gain and food consumption of the treated animals.

No remarkable internal or external observations related to the test item treatment were recorded for any of the animals during necropsy.

No test item could be detected in any of the samples of the control animals.

No test item could be detected in any of the organs analyzed in this study (gut, brain, liver, and spleen) under the conditions detailed in this report.

The near to complete amount (ca. 100%) of the applied test item was recovered from the stool of the animals.

Executive summary:

The aim of this study was to examine the toxicokinetic behaviour of the test item, based on OECD No. 417 guideline. It was performed in order to obtain information on the absorption, distribution and excretion of the test item administered by oral gavage to Wistar rats in an acute, and in a sub-acute, repeated-dose phase at 2 selected dose levels (acute dose: 2000mg/kg bw;14 days repeated-dose: 1000 mg/kg bw). Presence of the test item was examined in excreted urine and faeces, and in selected organs (brain, liver, spleen and content-free, gastrointestinal tract).

 

8 male Wistar rats were assigned to the Study and allocated to a control, and a dosed group. Dosed animals were given the pure test item without any vehicle by oral gavage in an acute phase once, at the dose level of 2000 mg/kg bw, and in a second, repeated dose phase daily for 14 consecutive days at the dose level of 1000 mg/kg bw/day. The animals assigned to the control group were treated with distilled water in the same manner.

 

Parameters monitored during the study included mortality and clinical observations, body weight, body weight gain and individual food consumption. Urine and faeces were collected for analysis at 5 occasions for 72 hours during the acute phase, and weekly at three occasions during 24 hours per occasion in the repeated dose phase.

 

Necropsy and macroscopic examination was performed on all animals at the end of Phase 2 (Day 14P2). The animals were euthanized by exsanguination under pentobarbital anaesthesia. After the exsanguination, gastrointestinal tract from oesophagus to the rectum, brain, liver and spleen were weighed, taken into PE falcon tubes and kept frozen until extraction. Samples were extracted, and concentration of the test item in the tissues was measured by GC-FID analysis.

 

In summary, acute, oral gavage administration of SynNova® Base Oil to male Hannover Wistar rats at the dose level of 2000mg/kg bw, followed by a 3 days washout period and subsequent daily oral gavage administration for 14 days at a dose level of 1000 mg/kg bw/day did not result in any mortality or clinical signs under the conditions of this study.

 

There was no test item-related effect in body weight, body weight gain and food consumption of the treated animals.

 

No remarkable internal or external observations related to the test item treatment were recorded for any of the animals during necropsy.

 

No test item could be detected in any of the samples of the control animals.

 

No test item could be detected in any of the organs analyzed in this study (gut, brain, liver, and spleen) under the conditions detailed in this report.

 

The near to complete amount (ca. 100%) of the applied test item was recovered from the stool of the animals.