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Toxicological information

Repeated dose toxicity: oral

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Administrative data

Endpoint:
sub-chronic toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study without detailed documentation
Justification for type of information:
Succinic acid may be used as an analogue for alkylsuccinic acid as this is the potentially biologically cative part of the molecule.
Dicarboxylic acids are naturally occurring metabolic products of fatty acid oxidation, and are rapidly beta-oxidised. A category approach for short-medium chain dicarboxylic acids, including malonic acid and succinic acid, has been validated and used by various bodies including the Cosmetics Ingredient Review Panel and the European Food Safety Authority.The study was carried out to provide a comparison between the LLNA and GPMT tests, rather than to investigate the properties of the test materials, nevertheless it follows standard OECD guidelines and was carried out in accordance with GLP.

Data source

Reference
Reference Type:
review article or handbook
Title:
Unnamed
Year:
2003
Report Date:
2002

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: crystalline
Specific details on test material used for the study:
Test substance: disodium succinate hexahydrate (CAS No. 6106-21-4), Nippon Shokubai Co., Ltd., Purity 99.9%, Lot No. 9P01B

Test animals

Species:
rat
Strain:
Crj: CD(SD)
Sex:
male/female

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
water
Duration of treatment / exposure:
Exposure period : Males; for 52 daysFemales; from 14 days before mating to day 4 of lactation
Frequency of treatment:
Once daily
Doses / concentrationsopen allclose all
Dose / conc.:
0 mg/kg bw/day (nominal)
Remarks:
vehicle: distilled water
Dose / conc.:
100 mg/kg bw/day (nominal)
Dose / conc.:
300 mg/kg bw/day (nominal)
Dose / conc.:
1 000 mg/kg bw/day (nominal)
No. of animals per sex per dose:
12 animals/sex/dose
Control animals:
yes, concurrent vehicle

Examinations

Sacrifice and pathology:
Hematological, blood biochemical, and histopathological examinations were performed in both sexes, and urinalysis was conducted in males.

Results and discussion

Results of examinations

Clinical signs:
effects observed, treatment-related
Description (incidence and severity):
Loosening of stool was observed in 1 and 4 males in the 100 and 1000 mg/kg groups and 1 female in the 1000 mg/kg group, respectively. This finding was a mild one and not accompanied by dirty hair in any group. One male in the 100mg/kg group and 1 female in the 1000 mg/kg group showed this finding in 1 day only, but 3 males except one male in the 1000 mg/kg group showed this finding in 3 to 4 days. In addition, for males, there were alopecia in 2 and 3 animals in the 300 and1000 mg/kg groups, eschar in 1 and 2 animals in the 300 and 1000 mg/kg groups, ocular discharge in 1 animal each in the 300 and 1000 mg/kg groups, nasal discharge in 2 animals each in the 300 and 1000 mg/kg groups and salivation in 1 animal in the 1000 mg/kg group, respectively. For females, there was alopecia in 1, 2, 3 and 1 animals in the control, 100, 300 and 1000 mg/kg groups, eschar in 1 animal each in the 100 and 1000 mg/kg groups and salivation in 1 animal in the 1000 mg/kg group,respectively.
Mortality:
no mortality observed
Description (incidence):
No deaths were found in any groups.
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
no effects observed
Haematological findings:
no effects observed
Clinical biochemistry findings:
effects observed, treatment-related
Description (incidence and severity):
In males, sodium showed high values in the 300 and 1000 mg/kg groups compared with the control group. In addition, chloride showed high values in the 300 mg/kg group, which was a slight and insignificant change. Also, total bile acid showed low values in the 1000 mg/kg group. The values in the control group, however, scattered large, and those of most animals in the 1000 mg/kg group were within the scatter in the control group. In females, creatinine showed high values in the 300 mg/kg group, which was a change not related to the dose. In the 1000 mg/kg group, urea nitrogen showed high values.
Urinalysis findings:
effects observed, treatment-related
Description (incidence and severity):
There was moderate occult blood in 1 of 5 animals in the 300 mg/kg group and severe one in 1 of 5 animals in the 1000 mg/kg group. The protein of 300 mg/dL or more were observed in 1 of 5 animals in the 300 mg/kg group and 2 of 5 animals in the 1000 mg/kg group. In addition, the yellowbrownish urine was observed in 2 of 5 animals in the 1000 mg/kg group, which were the changes within the normal values. Also, the abnormally high volumes of 24-hour urine were observed in 1 animal each in the 100 and 300 mg/kg groups, but there was no intergroup difference in the results of urine volume and urinary osmotic pressure in the animals excepting these 2 animals.
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Description (incidence and severity):
In males, absolute adrenal weight showed significantly high values in the 1000 mg/kg group compared with the control group.In females, there was no significant difference in any organ determined between the treatment groups and the control group.
Gross pathological findings:
effects observed, non-treatment-related
Description (incidence and severity):
In males, red patches in the liver were observed in 1 animal in the 300 mg/kg group, white patches/region in the liver, deverticulum in the small intestine and hypertrophy of the testis in 1 animal each in the 1000 mg/kg group and nodes of the epididymis in 2 animals in the 1000 mg/kg group. In females, adhesion of the spleen was observed in 1 animal in the control group, black patches in the glandular stomach in 2 and 1 animals in the 300 and 1000 mg/kg groups, white patches in the liver in 1 animal in the 300 mg/kg group and yellow patches, hypophysial cyst and alopecia in 1 animal each in the 1000 mg/kg group, respectively.
Histopathological findings: non-neoplastic:
no effects observed
Description (incidence and severity):
In males, atrophy of the seminiferous tubule was observed in 1 animal in the 300 mg/kg group and dilation of the seminiferous tubule in 1 animal in the 1000 mg/kg group. Dilation of the seminiferous tubule was hemilaterally observed, and no abnormality was observed in the cells constituting the seminiferous epithelium. Spermatic granuloma in the epididymis was observed in 2 animals in the 1000 mg/kg group but not observed in other treatment groups. Necrosis of the liver was observed in 1 animal in the 1000 mg/kg group. No gastric finding was observed in all groups including the control group. Lymphocytic infiltration in the prostate was observed in 4and 1 animals in the control group and the 1000 mg/kg group, respectively. Prostatitis was observed in 1 animal in the 1000 mg/kg group. In the animal showing prostatitis, there were the findings of pyelitis and accompanied proliferation of transitional epithelium in the kidney and the findings of lymphocytic infiltration and proliferation of transitional epithelium in the urinary bladder. Other findings were those also observed in the control group or solitary occurrence.In females, necrosis of the mucosa in the glandular stomach were observed in 2 and 1 animals in the 300 and 1000 mg/kg groups, focal necrosis of the liver in 1 animal in the 1000 mg/kg group and necrosis of the liver in 1 animal in the 300 mg/kg group. In addition, proliferation of lymphatic tissues in the small intestine was observed in 1 and 4 animals in the control group and the 1000 mg/kg group, respectively. Other histopathological findings observed were those also observed in the control group or in a few animals only.For the testis in the control group and the 1000 mg/kg group, the number of seminiferous epithelial cells in the seminiferous tubule in the stage VIII was determined. As a result, the numbers of spermatogonia (type A), spermiocytes in the preleptotene stage, spermiocytes in the pachytene stage, round spermatids and Sertoli's cells showed no differences compared with the control group.

Effect levels

open allclose all
Dose descriptor:
NOAEL
Effect level:
100 mg/kg bw/day (nominal)
Based on:
test mat.
Remarks:
equivalent to 60 mg/kg disodium succinate
Sex:
male
Basis for effect level:
clinical biochemistry
urinalysis
Dose descriptor:
NOAEL
Effect level:
300 mg/kg bw/day (nominal)
Based on:
test mat.
Remarks:
equivalent to 180 mg/kg disodium succinate
Sex:
female
Basis for effect level:
clinical biochemistry

Target system / organ toxicity

Key result
Critical effects observed:
yes
Lowest effective dose / conc.:
100 mg/kg bw/day (nominal)
System:
urinary
Organ:
not specified
Treatment related:
yes
Dose response relationship:
yes
Relevant for humans:
not specified

Applicant's summary and conclusion

Conclusions:
Based on the higher levels of urinary protein in males and blood urea nitrogen in females, the NOAEL of disodium succinate hexahydrate for repeated dose toxicity was considered to be 100 mg/kg bw/day for male rats and 300 mg/kg bw/day for female rats (100 and 300 mg of disodium succinate hexahydrate are equivalent to 60 and 180 mg of disodium succinate , respectively).
Executive summary:

In a combined repeated dose toxicity study with the reproduction/developmental toxicity screening test [OECD TG 422], Crj: CD (SD) IGS rats were given disodium succinate hexahydrate by gavage at 0, 100, 300, or 1,000 mg/kg bw/day. Males were dosed for 52 days from day 14 before mating and females were dosed from day 14 before mating to day 4 of lactation throughout the mating and pregnancy period. Blood urea nitrogen levels were increased in females at 1,000 mg/kg bw/day. Higher levels of urinary protein were found in one and two of the five males at 300 and 1,000 mg/kg bw/day, respectively, whereas no animals with these high levels were found in the control and 100 mg/kg bw/day groups. These findings suggest adverse effects of this compound on the kidney. Therefore, the NOAEL of disodium succinate hexahydrate for repeated dose toxicity was considered to be 100 mg (equivalent to 60 mg of disodium succinate)/kg bw/day for male rats and 300 mg (equivalent to 180 mg of disodium succinate)/kg bw/day for female rats.