Sodium dimethyl 5-sulphonatoisophthalate

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:

2012-08-14 to 2012-09-25

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well documented guideline and GLP compliant study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2013

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.7 (Repeated Dose (28 Days) Toxicity (Oral))

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: OPPTS 870.3050 Repeated Dose 28-Day Oral Toxicity Study in Rodents, EPA Health Effects Test Guideline, June 2000

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Sodium dimethyl 5-sulphonatoisophthalate

EC Number:

223-578-8

EC Name:

Sodium dimethyl 5-sulphonatoisophthalate

Cas Number:

3965-55-7

Molecular formula:

C10H10O7S.Na

IUPAC Name:

sodium 3,5-bis(methoxycarbonyl)benzenesulfonate

Test material form:

other: solid

Details on test material:

- Name of test material: Sodium dimethyl 5-sulphantosiphthalate (SIM-Ester)

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Toxi-Coop Zrt. Cserkesz u. 90. H-1103 Budapest, Hungary
- Age at study initiation:
Male animals: 39 – 41 days old; Female animals: 39 – 41 days old
- Weight at study initiation: Male animals: 130 – 143 g Female animals: 102 – 118 g
- Housing: 2 or 3 animals of the sex/ cage
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C):22 ± 3
- Humidity (%): 30 - 70
- Air changes (per hr): 8 – 12 air exchanges / hour by central air-condition system.
- Photoperiod (hrs dark / hrs light): 12 hours daily, from 6.00 a.m. to 6.00 p.m.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: 0.5% Methylcellulose

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS:
The test item was formulated in the vehicle (0.5 % Methylcellulose) in concentrations of 200, 50 and 12.5 mg/mL. The application volume was 5 mL/kg bw.

VEHICLE:
- Justification for use and choice of vehicle (if other than water): 0.5 % aqueous methylcellulose was a suitable vehicle to facilitate formulation analysis for the test item.
- Lot/batch no.:N83746634

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Five samples were taken (from different places) from each concentration and measured on 2 occasions. Similarly, one sample was taken from the control solution and analyzed. All formulations proved to be homogeneous. Measured concentrations varied between 100 and 110 % of the nominal concentrations.
The suitability of the chosen vehicle and sufficient stability for the test item at the intended concentrations were analytically verified up front. SIM-Ester was stable for 4 hours at room temperature (recovery: 99 % and 108 % of nominal concentrations of ca. 1 mg/mL and ca. 200 mg/mL, respectively) and for three days in refrigerator (recovery: 98 % and 104 % of nominal concentrations of ca. 1 mg/mL and ca. 200 mg/mL, respectively).

Duration of treatment / exposure:

28 days

Frequency of treatment:

The test item was administered in a single dose by oral gavage on a 7 days/week basis, every day at a similar time (+/- 2 hours). Concurrent control animals were handled (only vehicle) in an identical manner to the test groups.

Doses / concentrations

Remarks:

Doses / Concentrations:
62.5, 250 and 1000 mg/kg bw/day
Basis:
actual ingested

No. of animals per sex per dose:

Group 1 (control): 10 (including 5 recovery animals) per sex
Group 2 (62.5 mg/kg bw/day): 5 per sex
Group 3 (250 mg/kg bw/day): 5 per sex
Group 4 (1000 mg/kg bw/day): 10 (including 5 recovery animals) per sex

Control animals:

yes, concurrent vehicle

Details on study design:

- Post-exposure recovery period in satellite groups: 14 days

Positive control:

no

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Once a day, after treatment at approximately the same time.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Animals were inspected for signs of morbidity and mortality twice daily (at the beginning and end of each day). Detailed clinical observations were made on all animals outside the home cage in a standard arena once, prior to the first exposure and once weekly thereafter.

SENSORY REACTIVITY: Yes
- During the last exposure week.

BODY WEIGHT: Yes
- Time schedule for examinations: All animals were weighed in the treatment period with an accuracy of 1 g on Days 0, 7, 14, 21 and 27. Furthermore, body weight was recorded during the recovery period with same accuracy on Days 34 and 41.

FOOD CONSUMPTION: Yes
- The food consumption was determined in the treatment phase with an accuracy of 1 g on Days 7, 14, 21 and 27 by reweighing the non-consumed diet, and it was determined by the same way during the recovery period on Days 34 and 41.

HAEMATOLOGY: Yes
- Time schedule for collection of blood: One day after the last treatment and on recovery animals at the end of recovery period.
- Anaesthetic used for blood collection: Yes (Isofluran anesthesia)
- Animals fasted: Yes, animals were food deprived for approximately 16 hours prior to blood collection.
- Hematology parameters:
WBC: White Blood Cell (leukocyte) count,
RBC: Red Blood Cell (erythrocyte) count,
HGB: Hemoglobin concentration,
HCT: Hematocrit (relative volume of erythrocytes),
MCV: Mean Corpuscular (erythrocyte) Volume,
MCH: Mean Corpuscular (erythrocyte) Hemoglobin,
MCHC:Mean Corpuscular (erythrocyte) Hemoglobin Concentration,
RET: Reticulocytes,
PLT: Platelet (thrombocyte) count,
NEU: Neutrophil,
LYM: Lymphocyte,
EOS: Eosinophil,
MONO: Monocyte,
BASO: Basophil.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: One day after the last treatment and on recovery animals at the end of recovery period.
- Animals fasted: Yes, animals were food deprived for approximately 16 hours prior to blood collection.
- Blood coagulation parameters:
APTT: Activated partial Thromboplastin Time,
PT: Prothrombin Time,
ALT: Alanine Aminotransferase activity,
AST: Aspartate Aminotransferase activity,
GGT: Gamma Glutamyltransferase activity,
ALP: Alkaline Phosphatase activity,
TBIL: Total Bilirubin concentration,
CREA: Creatinine concentration,
UREA: Urea concentration,
GLUC: Glucose concentration,
CHOL: Cholesterol concentration,
BAC: Bile acids,
Ca++: Calcium concentration,
Na+: Sodium concentration,
K+: Potassium concentration,
Cl-: Chloride concentration,
ALB: Albumin concentration,
TPROT: Total Protein concentration,
A/G: Albumin/globulin ratio.

NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: during the last exposure week
- Dose groups that were examined: all animals of all groups
- Battery of functions tested: Sensory reactivity to different types of stimuli (e.g. auditory, visual and proprioceptive), grip strength and motor activity

ESTRUS CYCLE: Yes
- Time schedule for examinations: Prior to necropsy, the estrus cycle of all females were determined by taking vaginal smears.

Sacrifice and pathology:

GROSS PATHOLOGY: Yes, on each animal one day after the last treatment or termination of the recovery period. After examination of the external appearance, the cranial, thoracic and abdominal cavities were opened and the appearance of the tissues and organs were observed, and any abnormality was recorded with details of the location, color, shape and size.

ORGAN WEIGHT: YES, recorded prior to preservation (wet weight).
liver, kidneys, testes, epididymides, uterus, thymus, spleen, brain and heart, prostate and seminal vesicles with coagulating glands as a whole, adrenals, ovaries. Paired organs were measured together.

HISTOPATHOLOGY: Yes (see table)

Statistics:

Statistical analysis was done for the following data:
- body weight,
- food consumption,
- hematology,
- blood coagulation- clinical chemistry,
- organ weight data.
The heterogeneity of variance between groups was checked by Bartlett’s homogeneity of variance test. Where no significant heterogeneity was detected a one-way analysis of variance (ANOVA) was carried out. If the obtained result was significant Duncan Multiple Range test was used to access the significance of inter-group differences. Where significant heterogeneity was found, the normal distribution of data by Kolmogorov-Smirnov test was examined. In case of not normal distribution, the non-parametric method of Kruskal-Wallis One-Way analysis of variance was applied. If there was a positive result, the inter-group comparisons were performed using Mann-Whitney U-test. The frequency of clinical signs, pathology and histopathology findings were calculated.
Results were evaluated in comparison with values of control group (i.e. control value).

Results and discussion

Results of examinations

Details on results:

CLINICAL SIGNS AND MORTALITY
No mortality occurred. There were no toxic signs related to the test item effect at the daily clinical observations. The behavior and physical condition of animals were considered to be normal at each dose level during the treatment and recovery periods. Grey color of stool was noted for male and female animals at 1000 and 250 mg/kg bw/day at the daily and detailed weekly clinical observations from Days 14, 15 or 21 up to the end of the treatment period and for three days in the recovery period.

BODY WEIGHT AND WEIGHT GAIN
There were no statistically or biologically significant differences between the control and test item treated groups in the mean body weight and body weight gain during the entire observation period (treatment and recovery periods).

FOOD CONSUMPTION
The daily mean food consumption was similar in the control and test item treated groups during the treatment and recovery periods.

HAEMATOLOGY
Hematological investigations did not reveal any test item related changes in the examined parameters.

CLINICAL CHEMISTRY
Clinical pathology examinations did not reveal any pathologic changes in the examined blood coagulation or clinical chemistry parameters.

FUNCTIONAL OBSERVATION BATTERY
Functional observation battery did not demonstrate treatment-related differences with respect to the controls in the behavior or in reactions to different type of stimuli at the end of the treatment period.

ORGAN WEIGHTS
There were no test item related changes in the examined organ weights at any dose level.

GROSS PATHOLOGY
Necropsy observations did not reveal any test item related macroscopic findings in male or female animals, at any dose level tested.

HISTOPATHOLOGY
Histological examination did not reveal any toxic or test item related lesions in the investigated organs.

Effect levels

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 signs of toxicity were noted.

Target system / organ toxicity

Critical effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

Under the conditions of the present study, Sodium dimethyl 5-sulphonatoisophthalate (SIM-Ester) caused no signs of toxicity in male or female Wistar rats after 28-days oral (gavage) administration at 1000mg/kg bw/day, 250 mg/kg bw/day or 62.5 mg/kg bw/day.