Tricyclodecanedimethanol

Repeated dose toxicity: oral

Administrative data

Endpoint:

sub-chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

01 Feb 2013- 25 Oct 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted to OECD guidelines and in compiance with GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity Study in Rodents)

Deviations:

yes

Remarks:

Food consumption was recoreded for pre-treatment week. Method of analysis changed from HPLC to LC-MS/MS and LOD/LOQ not assessed. Any response form blank samples must be <20% lowest calibration standard.

GLP compliance:

yes (incl. QA statement)

Remarks:

Certificate of compliance issued by UK MHRA included in report

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

TCD Alcohol DM

IUPAC Name:

TCD Alcohol DM

Constituent 2

Reference substance name:

Tricyclodecanedimethanol

EC Number:

248-096-5

EC Name:

Tricyclodecanedimethanol

Cas Number:

26896-48-0

Molecular formula:

C12H20O2

IUPAC Name:

[3-(hydroxymethyl)tricyclo[5.2.1.0²,⁶]decan-8-yl]methanol

Test material form:

liquid: viscous

Details on test material:

- Name of test material (as cited in study report): TCD alcohol DM
- Substance type: Organic
- Physical state: clear, colourless very viscous liquid
- Analytical purity: 98%
- Lot/batch No.: 50000051564
- Expiration date of the lot/batch: 15 January 2014
- Storage condition of test material: Refrigerated in the dark

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: UK
- Age at study initiation: 41-47 days
- Weight at study initiation: Males = 133-173g: Females = 118-150g
- Housing: Cage: Polycarbonate body with a stainless steel mesh lid, changed at
appropriate intervals. Bedding: Wood based bedding which was changed at appropriate
intervals each week.
- Diet (e.g. ad libitum): Rat and Mouse No. 1 Maintenance Diet.
- Water (e.g. ad libitum): Potable water from the public supply. Non-restricted via polycarbonate bottles with sipper tubes.
- Acclimation period:12 days

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

IN-LIFE DATES: From: 07 May 2013 To: 28 Oct 2013

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

propylene glycol

Remarks:

+ ethyl acetate (w.w)

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS:

VEHICLE
- Concentration in vehicle:0, 50, 100, 200 mg/ml
- Amount of vehicle (if gavage): 5 ml/kg

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Homogeneity and stability assessed before commencement of treatment and test material found to be stable for >24h at 2-8 deg C and for 15 days at ambient temperature.

Duration of treatment / exposure:

13 weeks

Frequency of treatment:

Daily

No. of animals per sex per dose:

10 males and 10 females per treatment group

Control animals:

yes, concurrent vehicle

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice a day

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: twice daily

BODY WEIGHT: Yes
- Time schedule for examinations: weekly

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

OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: per-treatment and week 11

HAEMATOLOGY: Yes
- Time schedule for collection of blood: week 13
- Anaesthetic used for blood collection: Yes (isoflurane)
- Animals fasted: Yes
- How many animals: all
- Parameters checked: according to OECD 408

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: week 13
- Animals fasted: Yes
- How many animals: all
- Parameters checked: according to OECD 408

NEUROBEHAVIOURAL EXAMINATION: Yes
- Sensory reactivity and grip strength
- Touch response
- Huntingdon Life Sciences: PJJ0003
- Auditory startle reflex
- Tail pinch response
- Grip strength
- Motor activity

OTHER:
Sperm analysis: Immediately after scheduled sacrifice of each male, the left vas deferens, epididymis and testis was removed and the epididymis and testis were weighed.
-Analysis of: sperm motility, sperm morphology, sperm count

Oestrous cycles - vaginal smears

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes

Statistics:

All statistical analyses were carried out separately for males and females.
The following data types were analysed at each timepoint separately:
Body weight, using gains over appropriate study periods
Grip strength and motor activity
Haematology and blood chemistry
Oestrous cycles
Organ weights, absolute and adjusted for terminal body weight

Results and discussion

Results of examinations

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

There were three deaths during treatment. Female Nos. 132, 136 and 140 receiving 1000 mg/kg/day were despatched for welfare reasons on Day 12, 80 and 13 of treatment respectively. Clinical signs prior to despatch included; Female No. 132: decreased activity, laboured/shallow/slow breathing, râles (wet), sneezing and dark eyes. Female No. 136: excessive chewing, irregular/laboured breathing, râles (wet), piloerection, and prominent eyes. Female No. 140: decreased activity, laboured/shallow breathing, râles (wet), piloerection, elevated gait and distended abdominal area. Macroscopic examination revealed abnormal contents (gas) and/or distension of the caecum, colon, ileum, jejunum, stomach and/or incomplete lung collapse in each of these animals with no direct histopathologic correlate. In addition, histopathological examination revealed: No. 132, minimal haemorrhage that correlated to dark, multilobular, diffuse areas of the lungs and minimal apoptosis of the thymus correlating to dark thymus areas; No. 136, small spleen within no microscopic correlate, minimal lung and bronchi perivascular cell infiltrate and inflammation, minimal apoptosis of the thymus correlating to dark thymus areas; No. 140, minimal apoptosis and decreased cellularity of the thymus with no macroscopic correlate and a small spleen with slight white pulp atrophy observed microscopically.

Mortality:

mortality observed, treatment-related

Description (incidence):

There were three deaths during treatment. Female Nos. 132, 136 and 140 receiving 1000 mg/kg/day were despatched for welfare reasons on Day 12, 80 and 13 of treatment respectively. Clinical signs prior to despatch included; Female No. 132: decreased activity, laboured/shallow/slow breathing, râles (wet), sneezing and dark eyes. Female No. 136: excessive chewing, irregular/laboured breathing, râles (wet), piloerection, and prominent eyes. Female No. 140: decreased activity, laboured/shallow breathing, râles (wet), piloerection, elevated gait and distended abdominal area. Macroscopic examination revealed abnormal contents (gas) and/or distension of the caecum, colon, ileum, jejunum, stomach and/or incomplete lung collapse in each of these animals with no direct histopathologic correlate. In addition, histopathological examination revealed: No. 132, minimal haemorrhage that correlated to dark, multilobular, diffuse areas of the lungs and minimal apoptosis of the thymus correlating to dark thymus areas; No. 136, small spleen within no microscopic correlate, minimal lung and bronchi perivascular cell infiltrate and inflammation, minimal apoptosis of the thymus correlating to dark thymus areas; No. 140, minimal apoptosis and decreased cellularity of the thymus with no macroscopic correlate and a small spleen with slight white pulp atrophy observed microscopically.

Body weight and weight changes:

no effects observed

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):

Week 13 : when compared with the controls, a statistically significant reduction in activated partial thromboplastin time in males which was dose-related and females receiving 500 or 1000 mg/kg/day (not statistically significant)

Clinical biochemistry findings:

no effects observed

Behaviour (functional findings):

no effects observed

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

high absolute and body weight-adjusted liver weights in males and females at 500 or 1000 mg/kg/day; high body weight-adjusted kidney weight in males with a dose-relationship and females given 1000 mg/kg/day apparent

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Changes seen in nasal turbinates related to teatment

Histopathological findings: neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Changes related to treatment with TCD Alcohol DM were seen in the nose/turbinates.

Details on results:

Findings comprised of inflammatory exudate in the lumen of the nasal cavity and nasopharynx, degeneration/regeneration/inflammatory cell infiltration of the epithelium and deformity/fusion of turbinates. They were considered treatment related in all groups of both sexes.
Minimal findings, although not including turbinate changes, were seen in a single control female.
Changes of an uncertain relationship to treatment with TCD Alcohol DM were seen in the stomach.
Stomach - Epithelial hyperplasia of the non-glandular stomach was seen in occasional animals of both sexes given 500 and 1000 mg/kg/day and a single male given 250 mg/kg/day. In addition, a single case of erosion was seen in the non-glandular region of the stomach of a female given
1000 mg/kg/day. The low numbers affected and lack of consistency between the two sexes made this finding have an uncertain relationship to treatment.
All other microscopic findings were considered to be incidental and unrelated to treatment with TCD Alcohol DM.

No effects on sperm motility, morphology or concentration were observed after treatment at doses up to 1000 mg/kg/day.

Effect levels

Dose descriptor:

NOAEL

Effect level:

1 000 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: highest dose tested

Target system / organ toxicity

Critical effects observed:

not specified

Any other information on results incl. tables

There were three deaths during treatment. Female Nos. 132, 136 and 140 receiving 1000 mg/kg/day were despatched for welfare reasons on Day 12, 80 and 13 of treatment respectively.

Clinical signs prior to despatch included;

Female No. 132: decreased activity, laboured/shallow/slow breathing, râles (wet), sneezing and dark eyes.

Female No. 136: excessive chewing, irregular/laboured breathing, râles (wet), piloerection, and prominent eyes.

Female No. 140: decreased activity, laboured/shallow breathing, râles (wet), piloerection, elevated gait and distended abdominal area.

Macroscopic examination revealed abnormal contents (gas) and/or distension of the caecum, colon, ileum, jejunum, stomach and/or incomplete lung collapse in each of these animals with no direct histopathologic correlate.

In addition, histopathological examination revealed:

No. 132, minimal haemorrhage that correlated to dark, multilobular, diffuse areas of the lungs and minimal apoptosis of the thymus correlating to dark thymus areas;

No. 136, small spleen within no microscopic correlate, minimal lung and bronchi perivascular cell infiltrate and inflammation, minimal apoptosis of the thymus correlating to dark thymus areas;

No. 140, minimal apoptosis and decreased cellularity of the thymus with no macroscopic correlate and a small spleen with slight white pulp atrophy observed microscopically.

Microscopic findings were seen in the nose and comprised of inflammatory exudate in the lumen of the nasal cavity and nasopharynx, degeneration/regeneration/inflammatory cell infiltration of the epithelium and, deformity/fusion of turbinates. The microscopic changes in the nose/turbinates in two of the decedents (No. 132, 140) were of a severity to conclude that they were the factor responsible for the death whereas in the remaining animal (No. 136) these findings were not of a severity to be certain as to the cause of death. Similar findings in the nose/turbinates were also seen in terminal animals.

Applicant's summary and conclusion

Conclusions:

It was concluded, that for the assessment of systemic toxicity, oral administration of octahydro-4,7-methano-1H-indenedimethanol (TCD Alcohol DM), an industrial chemical intermediate, to RccHan™;WIST (Han Wistar) rats at dose levels of 250, 500 and 1000 mg/kg/day for 13 weeks the no-observed-adverse-effectlevel (NOAEL) in this study was considered to be 1000 mg/kg/day, and there were no adverse effects noted on the male and female reproduction organs, oestrous cycle, and sperm parameters.

It is acknowledged that adverse treatment related changes with TCD Alcohol DM were seen in the nose/turbinates of all treated groups of both sexes. Nasal findings comprised of inflammatory exudate in the lumen of the nasal cavity and nasopharynx,
degeneration/regeneration/inflammatory cell infiltration of the epithelium and deformity/fusion of turbinates. This pathology was considered to
be secondary to retrograde aspiration of material from the oropharynx into the nasopharynx and nasal cavity, this is considered to be a local effect, associated with the route of administration of this formulation and as such has been excluded from the assessment of systemic toxicity.

Executive summary:

The systemic toxic potential of TCD Alcohol DM, to Han Wistar (RccHanTM:WIST) rats by oral gavage administration was assessed over a period of 13 weeks. Three groups, each comprising ten males and ten females, received TCD Alcohol DM at doses of 250, 500 or 1000 mg/kg/day. A similarly constituted control group received the vehicle, 16% (w/w) ethylacetate in propylene glycol, at the same volume dose as the treated groups.

During the study, clinical condition, detailed physical and arena observations, sensory reactivity, grip strength, motor activity, body weight, food consumption, ophthalmoscopy, haematology (peripheral blood), blood chemistry, oestrous cycles, sperm analysis, organ weight, macropathology and histopathology investigations were undertaken.

Results:

Three females receiving 1000 mg/kg/day were killed for welfare reasons an say 12, 13 and 80 due to marked breathing impairment. Clinical signs prior to despatch included laboured/ shallow/irregular/slow breathing, räles (wet), decreased activity, piloerection, elevated gait, excessive chewing and distended abdomen. Macroscopic examination revealed abnormal contents (gas) and/or distension of the caecum, colon, ileum, jejunum, stomach and/or incomplete lung collapse in each of these animals with no direct histopathologic findings but associated with the histopathological changes in the nasal turbinates detailed in the following paragraph. The following section includes additional macropathology and histopathological examination findings: No. 132, minimal haemorrhage that correlated to dark, multilobular, diffuse areas of the Jungs and minimal apoptosis of the thymus correlating to dark thymus areas; No. 136, small spieen within no microscopic correlate, minimal lung and bronchi perivascular cell infiltrate and inflammation, minimal apoptosis of the thymus correlating to dark thymus areas; No. 140, minimal apoptosis and decreased cellularity of the thymus with no macroscopic correlate and a small spieen with slight white pulp atrophy observed microscopically.

Microscopic findings were seen in the nose and comprised of inflammatory exudate in the lumen of the nasal cavity and nasopharynx, degeneration/regeneration/inflammatory cell infiltration of the epithelium and, deformity/fusion of turbinates. The microscopic changes in the nose/turbinates in two of the decedents (No. 132, 140) were of a severity to conclude that they were the factor responsible for the death whereas in the remaining animal (No. 136) these findings were not of a severity to be certain as to the cause of death. Similar findings in the nose/turbinates were also seen in terminal animals.

Signs associated with dosing included räles and rapid breathing in individual animals at 500 or 1000 mg/kg/day during treatment. It is considered that this sign is predominately related to the dosing procedure and potential reflux of the formulation, rather than a systemic effect of treatment. Similar signs have been observed at physical examination in a few treated animals.

There were no treatment-related findings at the sensory reactivity, grip strength or motor activity investigations. Oestrous cycles were also considered unaffected by treatment.

 Body weight change and food consumption was unaffected by treatment with TCD Alcohol DM.

There were no treatment-related ophthalmoscopic findings.

During Week 13 of treatment haematological investigations revealed a shortening of activated partial thromboplastin times in males receiving 250, 500 or 1000 mg/kg/day and to a lesser degree in females receiving 500 or 1000 mg/kg/day. In addition, blood chemistry examination revealed slightly high alkaline phosphatase activities in males receiving 1000 mg/kg/day, although in the absence of any change in associated parameters (ALT and AST), the significance of this is unclear and also slightly high cholesterol concentration in these males.

Organ weight changes that were considered to be related to treatment were high absolute and body weight-adjusted liver weights in males and females at 500 or 1000 mg/kg/day, and high body weight-adjusted kidney weight in males with a dose-relationship apparent (absolute kidney weights were also slightly high) and females given 1000 mg/kg/day. In addition, there were high body weight-adjusted spieen weights in males given 1000 mg/kg/day.

There was no effect of treatment an sperm motility, morphology or concentration. There were no treatment-related macroscopic findings.

Treatment related microscopic changes were seen in the nose/turbinates of all treated groups. Findings comprised of inflammatory exudate in the lumen of the nasal cavity and nasopharynx, degeneration/regeneration/inflammatory cell infiltration of the epithelium and deformity/fusion of turbinates. In addition, epithelial hyperplasia of the non-glandular stomach was seen in occasional animals of both sexes given 500 and 1000 mg/kg/day and a single male given 250 mg/kg/day. A single case of erosion was seen in the non-glandular region of the stomach of a female given 1000 mg/kg/day, although these changes were of an uncertain relationship to treatment with TCD Alcohol DM.

Conclusion:

It was concluded, that for the assessment of systemic toxicity, oral administration of TCD Alcohol DM, an industrial chemical intermediate, to RccHanTM;WIST (Han Wistar) rats at dose levels of 250, 500 and 1000 mg/kg/day for 13 weeks the no-observed-adverse-effect-level (NOAEL) in this study was considered to be 1000 mg/kg/day.

It is acknowledged that adverse treatment related changes with TCD Alcohol DM were seen in the nose/turbinates of all treated groups of both sexes. Nasal findings comprised of inflammatory exudate in the lumen of the nasal cavity and nasopharynx, degeneration/regeneration/inflammatory cell infiltration of the epithelium and deformity/fusion of turbinates. This pathology was considered to be secondary to retrograde aspiration of material from the oropharynx into the nasopharynx and nasal cavity, this is considered to be a local effect, associated with the route of administration of this formulation and as such has been excluded from the assessment of systemic toxicity.