p-toluic acid

Repeated dose toxicity: oral

Administrative data

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2004

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: Guideline for the 28-Day Repeated Dose Toxicity Test in Mammalian Species (Chemical Substance Control Law of Japan)

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

p-toluic acid

EC Number:

202-803-3

EC Name:

p-toluic acid

Cas Number:

99-94-5

Molecular formula:

C8H8O2

IUPAC Name:

4-methylbenzoic acid

Test material form:

solid: crystalline

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Lot no. 10206
- Expiration date of the lot/batch:
- Purity test date:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material:
- Stability under test conditions:
- Solubility and stability of the test substance in the solvent/vehicle:
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium:

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing:
- Preliminary purification step (if any):
- Final dilution of a dissolved solid, stock liquid or gel:
- Final preparation of a solid:

FORM AS APPLIED IN THE TEST (if different from that of starting material)

OTHER SPECIFICS:

Test animals

Species:

rat

Strain:

Crj: CD(SD)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Chemicals Evaluation and Research Institute (CERI) Tokyo
- Females (if applicable) nulliparous and non-pregnant: [yes/no]
- Age at study initiation:
- Weight at study initiation:
- Fasting period before study:
- Housing:
- Diet (e.g. ad libitum):
- Water (e.g. ad libitum):
- Acclimation period:

DETAILS OF FOOD AND WATER QUALITY:

ENVIRONMENTAL CONDITIONS
- Temperature (°C):
- Humidity (%):
- Air changes (per hr):
- Photoperiod (hrs dark / hrs light):

IN-LIFE DATES: From: To:

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

CMC (carboxymethyl cellulose)

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

28 days

Frequency of treatment:

Daily

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

100 mg/kg bw/day (actual dose received)

Doses / concentrations 2

Dose / conc.:

300 mg/kg bw/day (actual dose received)

Doses / concentrations 3

Dose / conc.:

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

No. of animals per sex per dose:

Ten males and ten females were assigned to the control and high dose groups; five males and five females - to the low and middle dose groups.

Control animals:

yes, concurrent vehicle

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: no data
- Cage side observations checked in table [No.?] were included.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Clinical signs during the administration (28 days) and recovery (14 days) periods were recorded

BODY WEIGHT: Yes
- Time schedule for examinations: Body weight was measured three times at first week, then twice a week, including the days of termination of administration and recovery periods, and then at necropsy

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 / No / Not specified
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes / No / Not specified

FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: Yes / No / Not specified

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): Yes / No / Not specified
- Time schedule for examinations:

OPHTHALMOSCOPIC EXAMINATION: Yes / No / Not specified
- Time schedule for examinations:
- Dose groups that were examined:

HAEMATOLOGY: Yes
- Time schedule for collection of blood: Hematological and biochemical blood tests were performed on the samples obtained prior to necropsy.
- Anaesthetic used for blood collection: Yes (identity) / No / Not specified
- Animals fasted: Yes / No / Not specified
- How many animals:
- Parameters checked in table [No.?] were examined.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood:
- Animals fasted: Yes / No / Not specified
- How many animals:
- Parameters checked in table [No.?] were examined.

URINALYSIS: Yes / No / Not specified
- Time schedule for collection of urine:
- Metabolism cages used for collection of urine: Yes / No / Not specified
- Animals fasted: Yes / No / Not specified
- Parameters checked in table [No.?] were examined.

NEUROBEHAVIOURAL EXAMINATION: Yes / No / Not specified
- Time schedule for examinations:
- Dose groups that were examined:
- Battery of functions tested: sensory activity / grip strength / motor activity / other:

IMMUNOLOGY: Yes / No / Not specified
- Time schedule for examinations:
- How many animals:
- Dose groups that were examined:
- Parameters checked in table [No.?] were examined.

OTHER:

Sacrifice and pathology:

GROSS PATHOLOGY: Yes. Five males and five females were sacrificed and necropsied at the end of administration period (Day 29) and those from the control and high dose groups - at the end of recovery period (Day 43). The weight of the brain, thymus, heart, liver, kidneys, spleen, testes, adrenals, epididymis was measured. These organs from the control and high dose groups underwent histopathological examination by hematoxylin-eosin staining in addition to the lung, trachea, stomach, small and large intestine, prostate, seminal vesicle, ovary, uterus, vagina, urinary bladder, thyroids, femur, bone marrow, mesenteric and mandibular lymph nodes and spinal cord.

HISTOPATHOLOGY: Yes

Statistics:

Statistical analysis was conducted using Dunnett's test, Student's t-test, Aspin-Welch's t-test, chi square test and Mann-Whitney U-test.

Results and discussion

Results of examinations

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Food intake was significantly increased in female 1000 mg/kg bw/day group on Day 8, and thereafter a trend of food intake increase was observed during the administration period. No treatment-related changes in food intake were noticed in male groups during the administration period and in both sex groups during the recovery period.
Although the measuring water consumption was not conducted, apparent decreased volume of water in the bottled reservoir was observed in the cage-side macroscopic inspection.

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Description (incidence and severity):

No remarkable difference was observed in clinical signs, body weight and necropsy of all male and female rats even in the group treated with the highest dose.

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:

no effects observed

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

Slight and statistically insignificant decrease in platelet count was found in the female group at 1000 mg/kg bw/day. No other hematological changes were detected in either sex group.

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

not examined

Behaviour (functional findings):

no effects observed

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

no effects observed

Description (incidence and severity):

Histopathological examination did not show any difference between the control and 1000 mg/kg bw/day groups.

Gross pathological findings:

no effects observed

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

not examined

Effect levels

1

Key result

Dose descriptor:

NOEL

Effect level:

300 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

clinical signs

2

Key result

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:

clinical signs

Target system / organ toxicity

Key result

Critical effects observed:

no

Applicant's summary and conclusion

Conclusions:

Under the conditions of this 28 day repeat dose study it was determined NOEL 300 mg/kg bw; NOAEL (male) > 1000 mg/kg bw.