Sodium (3-hydroxy-2-pentylcyclopentyl)acetate

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:

from 2003-12-02 to 2004-09-02

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study, according to OECD guideline 407

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity Study in Rodents)

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Mexoryl SBO

IUPAC Name:

Mexoryl SBO

Details on test material:

- Name of test material (as cited in study report): Mexoryl SBO

Test animals

Species:

rat

Strain:

other: Sprague-Dawley, Crl CD (SD) IGS BR

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories France, l'Arbresle, France
- Age at study initiation: approximately 8 weeks old
- Weight at study initiation: 264-312 g males, 169-209 g females
- Housing: in suspended wire-mesh cages: two rats of the same sex and group
- Diet (e.g. ad libitum): A04 C pelleted maintenance diet, batch Nos. 30925, 31021 and 31118 (SAFE, Villemoisson, Epinay-sur-Orge, France), ad libitum, except fasting periods
- Water (e.g. ad libitum): tap water, ad libitum
- Acclimation period: 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22±2
- Humidity (%): 50±20
- Air changes (per hr): approximately 12 cycles/hour of filtered, non-recycled air
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

CMC (carboxymethyl cellulose)

Remarks:

0.5% of aqueous solution

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS:
The test item was administered as a suspension in the vehicle. The test item was mixed with the required quantity of vehicle in order to achieve the concentrations of 10, 30 and 100 mg/mL and then homogenized using a magnetic stirrer. The test item dosage forms were prepared daily (stability up to 4 hours) and stored at room temperature.

VEHICLE
- Concentration in vehicle: 10, 30 and 100 mg/mL
- Amount of vehicle (if gavage): 10 mL/kg/day
- Lot/batch no. (if required): 101K0185

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Diluted samples of dosage form were analyzed by reverse phase chromatography with MS detection (LC-MS, negative mode) after ionisation using an Electro-Spray Interface (ESI). One dilution was prepared for each sample, and one injection was performed for each final dilution. The test item peak area was determined for each sample and the corresponding concentration was calculated using the equation obtained from the calibration data. All the results are expressed as mg/mL of Mexoryl SBO.

Duration of treatment / exposure:

28 days

Frequency of treatment:

daily

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 100, 300 and 1000 mg/kg/day
Basis:
actual ingested

No. of animals per sex per dose:

10

Control animals:

yes, concurrent vehicle

Details on study design:

- Rationale for animal assignment (if not random): the required number of animals (40 males and 40 females) was selected according to body weight and clinical condition and allocated to groups (by sex), according to a computerized stratification procedure, so that the average body weight of each group was similar.

Examinations

Observations and examinations performed and frequency:

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

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: once a week

BODY WEIGHT: Yes
- Time schedule for examinations: once before allocation of the animals to groups, on the first day of treatment, and then once a week until the end of the study.

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: No data

OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: before beginning of the treatment period and at the end of the treatment period (week 4)
- Dose groups that were examined: control and high-dose groups

HAEMATOLOGY: Yes
- Time schedule for collection of blood: in week 5
- Anaesthetic used for blood collection: Yes (isoflurane)
- Animals fasted: Yes
- How many animals: all
- Following parameters were examined:
in peripheral blood: erythrocytes (RBC), hemoglobin (HB), mean cell volume (MCV), packed cell volume (PCV), mean cell hemoglobin concentration (MCHC), mean cell hemoglobin (MCH), thrombocytes (PLAT), leucocytes (WBC), differential white cell count with cell morphology, neutrophils (N), eosinophils (E), basophils (B), lymphocytes (L), monocytes (M), reticulocytes (RETIC), prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB).
in bone marrow: bone marow differential cell count.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: in week 5
- Animals fasted: Yes
- How many animals: all
- Following parameters were examined: sodium (Na+), potassium (K+), chloride (Cl-), calcium (Ca++), inorganic phosphorus (I.PHOS), glucose (GLUC), urea (UREA), creatinine (CREAT), total bilirubin (TOT.BIL), total proteins (PROT), Albumin (ALB), albumin/globulin (A/G), total cholesterol (CHOL), triglycerides (TRIG), alkaline phosphatase (ALP), aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT).

URINALYSIS: Yes
- Time schedule for collection of urine: in week 5
- Metabolism cages used for collection of urine: Yes
- Animals fasted: Yes
- Following parameters were examined:
quantitative parameters: volume, pH, specific gravity.
semi-quantitative parameters: proteins (PROT), glucose (GLUC), ketones (CETO), bilirubin (BILI), nitrites (NITR), blood (BLOOD), urobilinogen (UROB), cytology of sediment, leucocytes (WBC), erythrocytes (RBC), cylinders (CYLIN), magnesium ammonium phosphate crystals (AMM.PH), calcium phosphate crystals (CAL.PH), calcium oxalate crystals (CAL.OX.), cells (CELLS).
qualitative parameters: appearance (APP), color (COLOR)

NEUROBEHAVIOURAL EXAMINATION: No data

Sacrifice and pathology:

GROSS PATHOLOGY: Yes (see table 1)
HISTOPATHOLOGY: Yes (see table 1)

Statistics:

The sequence used for the statistical analyses of body weight, food consumption, hematology, blood bichemistry, urinalysis and organ weight data is presented in the Figure 1.

Results and discussion

Results of examinations

Clinical signs:

no effects observed

Description (incidence and severity):

except ptyalism, observed in 6/10 males and 7/10 females given 1000 mg/kg/day by gavage, during the last week of the study.

Mortality:

no mortality observed

Description (incidence):

except ptyalism, observed in 6/10 males and 7/10 females given 1000 mg/kg/day by gavage, during the last week of the study.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

Slightly higher body weight gain was recorded in males treated by oral route, without dose-relationship.

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not specified

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

not specified

Ophthalmological findings:

no effects observed

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

Slightly lower erythrocyte count, hemoglobin and mean cell hemoglobin concentrations as well as higher mean cell volume were noted at the end of the treatment period in males given 1000 mg/kg/day.

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

The only treatment-related difference consisted of slightly higher triglyceride level in animals given 1000 mg/kg/day.

Urinalysis findings:

no effects observed

Behaviour (functional findings):

not specified

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

Higher liver weights were noted in animals given 1000 mg/kg/day.

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

Liver enlargement was noted in 2/10 males and 1/10 females given 1000 mg/kg/day.

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Liver changes consisted of hepatocellular hypertrophy among animals given 1000 mg/kg/day.

Histopathological findings: neoplastic:

not specified

Details on results:

CLINICAL SIGNS AND MORTALITY
No unscheduled death occured during the study. No relevant clinical signs were noted, except ptyalism, observed in 6/10 males and 7/10 females
given 1000 mg/kg/day by gavage, during the last week of the study. This sign, commonly noted when a test item is administered by gavage, was not considered as an adverse effect.

BODY WEIGHT AND WEIGHT GAIN
Slightly higher body weight gain was recorded in males treated by oral route, without dose-relationship. This slight effect was not considered as an adverse effect.

OPHTHALMOSCOPIC EXAMINATION
There were no treatment-related ophthalmological findings.

HAEMATOLOGY
Slightly lower erythrocyte count, hemoglobin and mean cell hemoglobin concentrations as well as higher mean cell volume were noted at the end of the treatment period in males given 1000 mg/kg/day.

CLINICAL CHEMISTRY
The only treatment-related difference consisted of slightly higher triglyceride level in animals given 1000 mg/kg/day.

URINALYSIS
Lower urinary pH value was noted in animals given 300 and 1000 mg/kg/day. Since there were no other associated findings this effect was not considered as toxicologically significant.

ORGAN WEIGHTS
Higher liver weights were noted in animals given 1000 mg/kg/day.

GROSS PATHOLOGY
Liver enlargement was noted in 2/10 males and 1/10 females given 1000 mg/kg/day by oral route.

HISTOPATHOLOGY: NON-NEOPLASTIC
Liver changes consisted of hepatocellular hypertrophy among animals given 1000 mg/kg/day.

Effect levels

Key result

Dose descriptor:

NOAEL

Effect level:

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

Based on:

test mat.

Sex:

male/female

Basis for effect level:

gross pathology

histopathology: non-neoplastic

organ weights and organ / body weight ratios

Target system / organ toxicity

Key result

Critical effects observed:

yes

Lowest effective dose / conc.:

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

System:

hepatobiliary

Organ:

liver

Treatment related:

yes

Dose response relationship:

no

Relevant for humans:

not specified

Applicant's summary and conclusion

Conclusions:

No adverse effects were observed at 100 and 300 mg/kg/day. At 1000 mg/kg/day, ptyalism was observed in both sexes and some hematological (lower erythrocyte count, hemoglobin and mean cell hemoglobin concentrations and higher mean cell volume) and blood biochemical (higher triglyceride level) changes were noted. Microscopic examination showed hepatocellular hypertrophy in males and females, correlating with higher liver weights and liver enlargement among these animals.
Consequently, under the experimental conditions of the study, taking into account the slight change in the hemoglobin concentration in females given 300 mg/kg/day, the No Observed Adverse Effect Level (NOAEL) by oral route is considered as 300 mg/kg/day.

Executive summary:

The objective of this GLP and OECD guideline 407 conform study was to evaluate the potential toxicity of the test item Mexoryl SBO, following daily oral (gavage) administration to rats for 4 weeks. The oral route was selected since it is presumed to ensure an absorption at least equal to that expected from percutaneous absorption of the test item in man. Three treated groups of 10 male and 10 female Sprague-Dawley rats received the test item daily, by gavage at the dose-level of 100, 300 or 1000 mg/kg/day. One additional group of 10 males and 10 females received the vehicle alone (0.5 % aqueous carboxymethylcellulose) under the same experimental conditions (i.e. by gavage) and acted as oral control group. The animals were checked daily for mortality and clinical signs. Body weight and food consumption were recorded once a week. Ophthalmological examinations were carried out before and at the end of the treatment period. Hematological and blood biochemical investigations and urinalysis were performed at the end of the treatment period. On completion of the treatment period, the animals were killed and submitted to a full macroscopic post-mortem examination. Designated organs were weighed and selected tissue specimens were preserved. A microscopic examination was performed on selected tissues from animals of all the control and high-dose groups (groups 1 and 4) and on all macroscopic lesions (all groups). No unscheduled death occurred during the study. No relevant clinical signs were noted. Slightly higher body weight gain was recorded in males treated by oral route, without dose-relationship. This slight effect was not considered as an adverse effect. The food consumption was considered to be unaffected by treatment with the test item. There were no treatment-related ophthalmological findings. Slightly lower erythrocyte count, hemoglobin and mean cell hemoglobin concentrations as well as higher mean cell volume were noted at the end of the treatment period in males given 1000 mg/kg/day. The only treatment-related difference consisted of slightly higher triglyceride level in animals given 1000 mg/kg/day. Lower urinary pH value was noted in animals given 300 and 1000 mg/kg/day. Since there were no other associated findings this effect was not considered as toxicologically significant. Higher liver weights were noted in animals given 1000 mg/kg/day. Liver enlargement was noted in 2/10 males and 1/10 females given 1000 mg/kg/day. Liver changes consisted of hepatocellular hypertrophy among animals given 1000 mg/kg/day. Under the experimental conditions of the study, taking into account the slight change in the hemoglobin concentration in females given 300 mg/kg/day, the No Observed Adverse Effect Level (NOAEL) by oral route is considered as 300 mg/kg/day.