Sodium 2-(1-carboxylatoethoxy)-1-methyl-2-oxoethyl isooctadecanoate

Repeated dose toxicity: oral

Administrative data

Endpoint:

chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2006-06-02 to 2010-02-26

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 452 (Chronic Toxicity Studies)

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Reference substance 001

Cas Number:

25383-99-7

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 268611604
- Expiration date of the lot/batch: October 27 2007


STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: ambient temperature, in tightly sealed container

Test animals

Species:

rat

Strain:

Wistar

Remarks:

albino

Details on species / strain selection:

This strain was used because it is routinely used by the test facility for this type of studies.

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: colony maintained under SPF-conditions at Charles River (Sulzfeld, Germany)
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation: 6 weeks old
- Weight at study initiation: 128 to 203 g (mean 166 g) for males and from 115 to 152 g (mean 136 g) for females
- Housing: The animals were housed in macrolon cages (one rat/cage) with wood shavings as bedding material and shreds of paper as environmental enrichment in a controlled environment.
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: At arrival (males on 17 May 2006 and females on 24 May 2006), the animals were taken in their shipping boxes into an animal room (females in room number 05.7.12, males in room number 05.2.11+05.2.16), checked for overt signs of ill health and anomalies, and kept in quarantine. Their microbiological status was checked by the conduct of serology in samples taken from rats of the same shipment (the samples were collected on 17 [males] and 31 [females] May 2006). The serology results confirmed that the microbiological status of the animals was acceptable. On 31 May 2006, the females were transferred to room 05.2.11+05.2.16. The rats were acclimatized to the conditions in this room until initiation of treatment (males on 6 June 2006 and females on 15 June 2006).

DETAILS OF FOOD AND WATER QUALITY:
Until initiation of treatment, the rats received a cereal-based (closed formula) rodent diet (Rat & Mouse No. 3 Breeding Diet, RM3; pelleted) from a commercial supplier (SDS Special Diets Services, Witham, England). From the start of the treatment period, controls were kept on powdered RM3 diet without test substance and the animals of the test groups were kept on powdered RM3 diet containing the test substance. The feed was provided in stainless steel cans, covered by a perforated stainless steel plate to prevent spillage. The feed in the feeders was refreshed once per week and filled up when necessary.

Each cage was supplied with domestic mains tap-water suitable for human consumption (quality guidelines according to Dutch legislation based on EC Council Directive 98/83/EC). The water was given in polypropylene bottles, which were cleaned weekly and filled as needed.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20- 24 degrees
- Humidity (%): 40- 70%
- Air changes (per hr): 10 per hour
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: 2006-06-02 to 2007-06-07

Administration / exposure

Route of administration:

oral: feed

Details on route of administration:

This administration method was selected in accordance with the anticipated route of human exposure (the test substance is intended for use in food).

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

- DIET PREPARATION
- Rate of preparation of diet (frequency): once a month (on 2 June, 6 July, 3 August, 29 August, 27, September, 27 October, 20 November, and 20 December 2006, and 22 January, 19 February, 13 March, 16 April and 1 May 2007).
- Storage temperature of food: <-18 °C (in portions sufficient for one week, about 6 kg per portion for males and 5.25 kg for females)

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Analyses were conducted to confirm the stability of the test substance in the diet upon storage in the animal room for 7 days (in an open container) or in a freezer (<-18 °C) for at least 5 weeks (in a closed container). For this purpose, samples of the first batch of diets used in the toxicity study (control diet, low-dose, mid-dose and high-dose diet) were analysed a few days after the day of diet preparation (t=0) and after the different storage periods. The homogeneity of the test substance in the diet was examined by analysing five samples per concentration, taken at different locations in the feed container. The samples were taken from the first batch of diets used in the toxicity study. The content (achieved concentration) ofthe test substance was checked by analysis in six different batches of diets used in the toxicity study (batches 1, 2, 5, 8, 11 and 13).

Duration of treatment / exposure:

One year

Frequency of treatment:

7 days per week

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

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

Remarks:

Males and females fed diet with 0% test substance (control)

Doses / concentrations 2

Dose / conc.:

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

Remarks:

Males fed diet containing 1.25% (w/w) of test substance

Doses / concentrations 3

Dose / conc.:

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

Remarks:

Females fed diet containing 1.25% (w/w) of test substance

Doses / concentrations 4

Dose / conc.:

1 115 mg/kg bw/day (actual dose received)

Remarks:

Males fed diet containing 2.5% (w/w) of test substance

Doses / concentrations 5

Dose / conc.:

1 339 mg/kg bw/day (actual dose received)

Remarks:

Females fed diet containing 2.5% (w/w) of test substance

Doses / concentrations 6

Dose / conc.:

2 214 mg/kg bw/day (actual dose received)

Remarks:

Males fed diet containing 5% (w/w) of test substance

Doses / concentrations 7

Dose / conc.:

2 641 mg/kg bw/day (actual dose received)

Remarks:

Females fed diet containing 5% (w/w) of test substance

No. of animals per sex per dose:

30 males and 30 females per dose

Control animals:

yes, plain diet

Details on study design:

- Dose selection rationale: 5% of the test substance in the diet was selected as high-dose level to test the highest dose feasible and yet avoid nutritional problems.
- Rationale for animal assignment (if not random): About two weeks before the start of the treatment period (males on day -14, females on day -15), the rats were weighed and checked for overt signs of ill health and anomalies. After weighing, 120 rats/sex were allocated to the four experimental groups proportionately to body weight by computer randomisation (the animals of which the body weight deviated most from the mean were automatically eliminated).

Positive control:

None

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

DETAILED CLINICAL OBSERVATIONS: If necessary based on cage side observations
- Time schedule: daily

BODY WEIGHT: Yes
- Time schedule for examinations: The body weight of each animal was recorded at initiation of treatment (day 0), then weekly for the first 13 weeks, at the end of week 16 (day 112) and once every four weeks thereafter.

FOOD CONSUMPTION AND COMPOUND INTAKE:
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes. Food and water consumption were measured over 7-day periods, by weighing the feeders and drinking bottles, weekly for the first 13 weeks, in week 16, and once every four weeks thereafter (at the same intervals as the body weight measurements). The results were expressed in g per animal per day. Feed spillage was monitored by visual inspection. When substantial spillage was observed, spilled feed was collected, if feasible, and accounted for. A few animals repeatedly turned over their feeders. To prevent this, their feeders were made heavier. Spillage of feed or water was observed for a few animals from different groups but there was no increased spillage in the groups receiving the test substance.
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Not specified

OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: Ophthalmoscopic observations were made in all rats prior to the start of treatment (males on days -7 and -6, females on days -2 and -1) and in all animals of the control group and the high-dose group towards the end of the treatment period (males on day 358, females on day 357).
- Dose groups that were examined: control and high dose group at end of study

HAEMATOLOGY: Yes
- Time schedule for collection of blood: Week 3, week 13 and week 26, and termination
- Anaesthetic used for blood collection: Not specified
- Animals fasted: Yes
- How many animals: all survivors
- Parameters examined: red blood cells (RBC) including mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC), haemoglobin (Hb), packed cell volume (PCV), reticulocytes, total white blood cells (WBC), differential white blood cells (i.e. lymphocytes, neutrophils, eosinophils, basophils and monocytes), prothrombin time (PT), thrombocytes.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: Same 4 points as haematology
- Animals fasted: Yes
- How many animals: all surviving
- Parameters examined: alkaline phosphatase activity (ALP), aspartate aminotransferas eactivity (ASAT), alanine aminotransferase activity (ALAT), gamma glutamyl transferase activity (GGT), sorbitol dehydrogenase activity (SDH), 5'-nucleotidase activity (5'-ND), cholinesterase activity, bilirubin (total), bile acids (total), total protein, albumin, ratio albumin to globulin (calculated), glucose, cholesterol (total), phospholipids, triglycerides, creatinine, urea, inorganic phosphate (PO4), calcium (Ca), chloride (Cl), potassium (K), sodium (Na)

URINALYSIS: Yes
- Time schedule for collection of urine: week 2, 13, 26, 52
- Metabolism cages used for collection of urine: Yes
- Animals fasted: Yes
- Parameters examined: urine volume, density, appearance, semi-quantitative (dipstick measurements) and microscopy of the sediment

NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: first exposure, 12, 25, 51
- Dose groups that were examined: all
- Battery of functions tested: Functional Observational Battery (FOB) tests, including assessment of grip strength and sensory reactivity to stimuli of different types, and spontaneous motor activity measurements

IMMUNOLOGY: Primary indicators of immune toxicity derived from routine measurements were evaluated as an immunotoxicity screen. These routine tests included:
- haematology (e.g. total and differential white blood cell counts),
- clinical chemistry (e.g. total protein, albumin, albumin/globulin ratio, transaminases),
- body weight and organ weights (thymus, spleen),
- gross and microscopic examination of the lymphoid tissues (spleen, lymph nodes, thymus, Peyer's patches, bone marrow),
- microscopic examination of possible immune-related processes in non-lymphoid organs (e.g. mononuclear cell infiltrates in liver or kidneys).

Sacrifice and pathology:

GROSS PATHOLOGY: All animals were necropsied and gross observations recorded. The rats were sacrificed, after overnight fasting, by exsanguination from the abdominal aorta under CO2/O2 anesthesia. Liver, kidneys, adrenals, brain, heart, thymus, spleen, thyroid (with parathyroids), ovaries, uterus, testes, and epididymides weights were recorded for all animals.

HISTOPATHOLOGY: Tissues were fixed in a neutral aqueous phosphate-buffered 4% solution of formaldehyde, embedded in paraffin, sectioned, stained with haematoxylin and eosin, and examined microscopically. Tissues from all control and high-dose (5% sodium stearoyl lactylate or SSL) animals (and one low-dose (1.25%) female and one mid-dose (2.5%) female that were sacrificed early) and all gross lesions were examined histopathologically. The histopathological examination of the uterus and vagina was extended to all females of the low- and mid-dose groups (1.25 and 2.5% SSL) due to an observation of an increased incidence of endometrial stromal polyps in the high-dose group (5% SSL).

Collected and preserved tissues and organs included lungs, trachea/bronchi, brain, spinal cord, sublingual, submaxillary, and parotid salivary glands, thymus, heart, sternum with bone marrow, adrenals, liver, spleen, kidneys, thyroid/parathyroid, urinary bladder, ovaries and fallopian tubes, uterus, vagina, esophagus, ileum, cecum, prostate and seminal vesicles with coagulating glands, peripheral nerve (sciatic), stomach, duodenum, jejunum, colon, rectum, GALT (gut associated lymphoid tissue, including Peyer’s patches), mesenteric and mandibular lymph nodes, axillary lymph nodes, pancreas, pituitary, aorta, mammary gland, harderian gland, skin, nasal turbinates, skeletal muscle, femur with joint, epididymides, testes, eyes, exorbital lachrymal glands, Zymbal’s gland, and all gross lesions.

Other examinations:

Faeces were collected and analyzed in order to determine possible energy loss as exemplified by lower body weights, particularly in high-dose females. In treatment week 33–34, faeces were collected from 5 female rats/group over 3 consecutive days. Feces were pooled per animal and analysed for dry matter, crude protein (Kjeldahl method), crude fat (Weibull–stoldt method), and ash. The carbohydrate fraction and consumption and excretion of energy were calculated.

Statistics:

Statistic tests used for specific endpoints:
- Feed and water consumption: Dunnett’s multiple comparison test.
- Semi-quantitative urinary observations and urinary sediment measures: one-way analysis of variance (ANOVA) after checking for homogeneity of variances (Bartlett’s test) and normality of data distribution (Shapiro–Wilk test). If variances were not homogeneous or the data not normally distributed, the data were stepwise log or rank transformed prior to ANOVA. If effecthad p < 0.05, Dunnett’s multiple comparison test was used for intergroup comparisons with control.
- Body weight, organ weight and clinical pathology data: first tested for normal distribution (Shapiro–Wilk test) and homogeneity of variances (Bartlett’s test). A ‘‘best” transformation of the data was determined; the (transformed) data were then analysed to test for a dose-related trend. If present, the lowest dose level affected was identified using the Williams test for parametric data or the Shirley test for non-parametric data. If no statistically significant trend effect was identified, but the data showed non-homogeneity of group means in an F-ratio test, the data were analysed by Dunnett’s test (parametric) or Steel’s test (non-parametric) in order to identify significant differences from the control group.
- Body weight, organ weight, haematology, clinical chemistry and faecal excretion data also analysed via ANOVA.
- Incidence of histopathological changes: Fisher’s exact probability test
- FOB and MA parameters were analysed as follows:
1. continuous measures, one-way ANOVA, followed by Dunnett’s post-hoc group comparisons;
2. rank order data, Kruskal–Wallis analysis of variance;
3. categorical data, Pearson chi-square analysis;
4. motor activity/total distance moved, one-way ANOVA, followed by Dunnett’s post-hoc group comparisons;
5. motor activity/habituation of activity, repeated measures ANOVA.
- Levels of significance were set at p < 0.05 and p < 0.01.

Results and discussion

Results of examinations

Clinical signs:

no effects observed

Description (incidence and severity):

There were no treatment-related clinical signs. The signs observed occurred in only one or a few animals of a group or the incidences were distributed about equally between groups. Many of the ocular lesions occurred following blood collection from the orbital plexus.

Mortality:

mortality observed, non-treatment-related

Description (incidence):

- One male rat (number 240) of the high-dose group was humanely killed on day 28. On this day, the animal showed piloerection and an abdominal nodule. Between days 21 and 28, it showed weight loss and reduced food consumption whereas its water
consumption was relatively high. The animal showed several signs of renal pathology, including hydronephrosis and increased plasma levels of urea and creatinine.
- One female (number 91) of the low-dose group was humanely killed on day 315 when it was lethargic and pale and showed piloerection and haemorrhagic vaginal discharge. Between days 280 and 308, this animal showed weight loss and reduced food and water consumption.
- One female (number 147) of the mid-dose group was humanely killed on day 328 when it looked pale and showed haemorrhagic vaginal discharge. Before this day, the animal grew, ate and drank normally.
Gross and histopathological examinations showed that the untimely death of these 3 animals was not ascribed to treatment.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

From day 7, mean body weights of high-dose females were statistically significantly (ANOVA/Dunnett's test) lower than those of controls. The differences from controls were about 4-5% up to day 28 and generally about 6-7% thereafter. Trend analysis showed additional statistical significances in high-dose males and mid and low-dose females. However, the mean body weights in these groups were only slightly (about 3-4%) lower than in controls and not statistically significant upon analysis by ANOVA. Therefore, no toxicological significance was attached to these trend analysis results in high-dose males and low- and mid-dose females.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

High-dose males consumed somewhat less food than controls throughout the study. The difference from controls was generally statistically significant and most pronounced in the first week (12% on day 7, and about 4-6% thereafter). Food consumption of low and mid-dose males showed no appreciable difference from that of controls (a few statistically significant differences between the low- or mid-dose group and the control group were considered irrelevant).

In females, food consumption was statistically significantly decreased at all dose levels during the first eight weeks of the treatment period (dose-dependently; about 5% at the low-dose, 6-7% aI the mid-dose, and 10-12% at the high-dose). Thereafter, only the decreases in high-dose females generally remained statistically significant until the end of the study, whereas the decreases in mid-dose females were no longer statistically significant after day 196. Food consumption in low-dose females approached that of controls after week 8. Since the relative differences from controls were small, the lower body weight and feed consumption in high-dose females were not considered toxicologically significant.

Food efficiency:

not examined

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

effects observed, non-treatment-related

Description (incidence and severity):

High-dose females tended to drink less (about 7-10%) water than controls between days 42 and 168. Except for day 105-112, the differences from controls were not statistically significant. Water consumption of male rats showed no relevant differences between rats fed the test substance and controls. Water consumption data showed no consistent differences between the treated groups and the control group.

Ophthalmological findings:

no effects observed

Description (incidence and severity):

Ophthalmoscopic examination revealed no treatment-related ocular changes.

Haematological findings:

effects observed, non-treatment-related

Description (incidence and severity):

Haematology results showed lower (about 20%) mean values for total white blood cells and the absolute numbers of lymphocytes, eosinophils and basophils in high-dose males at the end of the treatment period. Eosinophils (percentage and absolute number) in high-dose males were also lower than in controls in week 13 and week 26. The observation of these lower white blood cell values at the highest dose level is suggestive of a relation with treatment. However, there were no treatment-related changes in the primary lymphoid organs bone marrow (morphology) and thymus (morphology and weight). Moreover, white blood cell values in high-dose males were within the physiological rangel. Therefore, the lower white blood cell values noted in high-dose males were considered not to be related to the ingestion of the test substance.

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

Evaluation of clinical chemistry parameters revealed statistically significant increases in ALKP, ALT, SDH and albumin/globulin ratio, and decreases in total protein, 5'-ND, plasma lipids (cholesterol, phospholipids, and, less consistently, triglycerides) and PO4 primarily at the mid- and high-dose levels (2.5 and 5%) in both sexes. However, these changes were of low magnitude and not accompanied by corroborative pathological conditions (e.g., damage to the liver, kidneys, thyroid, or intestines), so they were considered of no toxicological significance.

Other statistically significant differences in clinical chemistry parameters were sporadic across treatment group, sex, and/or time and were not ascribed to treatment.

Urinalysis findings:

effects observed, treatment-related

Description (incidence and severity):

Significant changes in urinalysis data were limited to a slight increase in pH in the high-dose (5%) group males (week 52) and mid- and high-dose (2.5 and 5%) group females (weeks 26 and 52). An isolated increase in urinary pH was considered not to be
of toxicological significance.

Behaviour (functional findings):

no effects observed

Description (incidence and severity):

Evaluation of information available from daily clinical observations, FOB and motor activity testing did not reveal any neurobehavioural effects from the test substance.

Immunological findings:

no effects observed

Description (incidence and severity):

Immunotoxicity screening by evaluation of relevant data from haematology, clinical chemistry, weights of thymus and spleen, and pathology did not reveal any primary indicator of immunotoxicity.

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

Organ weights showed no significant changes with the exception of slightly lower mean values for absolute and relative liver weight in males at all dose levels. The decreases in liver weights were only slight (5–10%), and not reflective of hepatotoxicity as corroborated by a lack of treatment-related pathological changes in the liver.

Gross pathological findings:

no effects observed

Description (incidence and severity):

Gross examination of the surviving animals did not reveal treatment-related changes.

Neuropathological findings:

no effects observed

Description (incidence and severity):

Evaluation of information available from daily clinical observations, FOB and motor activity testing, gross examination at necropsy, weight of the brain and routine microscopic examinations did not reveal any changes indicative of neurotoxic effects of the test substance.

Histopathological findings: non-neoplastic:

effects observed, non-treatment-related

Description (incidence and severity):

Microscopic examination of the organs and tissues revealed tumorous and nontumorous histopathological changes in all groups, including controls. The non-tumourous changes were of a type commonly observed in rats of this strain and age, and occurred only incidentally or at comparable or random incidences between the groups, including controls. Various tumours were observed in a few rats of all groups, including controls (i.e., cortical adenoma of the adrenal
gland [benign], lymphoma [malignant], hepatocellular adenoma [benign], adenocarcinoma in mammary gland [malignant], adenoma [benign] in the pituitary gland, adenocarcinoma [malignant] in the pituitary gland, C-cell adenoma [benign] and cystic follicular cell adenoma [benign] in the thyroid). These tumuors were considered not to be related to treatment because they were observed in a single or a few animals only and are known to occur spontaneously in older (1 year or older) rats of this strain and age.

The only noteworthy microscopic observation in this study was an increase in the incidence of endometrial stromal polyps, a benign uterine tumor, in mid- and high-dose (2.5 and 5%) females. The endometrial stromal polyps were observed in the uterus of one control, two low-dose (1.25%), six mid-dose (2.5%), and six high-dose (5%) females. The lesion varied from a macroscopically not detected small sessile nodule restricted to the endometrial wall to an oedematous (congested) polypoid mass protruding into the uterine lumen or through the cervix into the vagina as observed in two of the rats that were sacrificed prior to week 53. All polyps had a fibrovascular stroma with various amounts of collagen and were covered with cuboidal to columnar epithelium which was continuous with and similar with respect to oestrous cycle morphology to the surrounding lining endometrial epithelium. Some had a cystic appearance due to dilated endometrial glands. There were no observed hyperplasia of endometrial glands, increased mitotic activity, cellular atypia, or a relationship between dose level and the size of the mass. Altogether, the reported effects were considered not to be related to treatment.

Histopathological findings: neoplastic:

effects observed, non-treatment-related

Description (incidence and severity):

Microscopic examination of the organs and tissues revealed tumorous and nontumorous histopathological changes in all groups, including controls. The non-tumourous changes were of a type commonly observed in rats of this strain and age, and occurred only incidentally or at comparable or random incidences between the groups, including controls. Various tumours were observed in a few rats of all groups, including controls (i.e., cortical adenoma of the adrenal
gland [benign], lymphoma [malignant], hepatocellular adenoma [benign], adenocarcinoma in mammary gland [malignant], adenoma [benign] in the pituitary gland, adenocarcinoma [malignant] in the pituitary gland, C-cell adenoma [benign] and cystic follicular cell adenoma [benign] in the thyroid). These tumuors were considered not to be related to treatment because they were observed in a single or a few animals only and are known to occur spontaneously in older (1 year or older) rats of this strain and age. Therefore, the reported effects were considered not to be related to treatment.

Other effects:

effects observed, non-treatment-related

Description (incidence and severity):

Analysis of faeces: Compared with controls, the total amounts (in 3 days) of food consumed and faeces excreted were lower in high-dose females, whereas food consumption per kg body weight was not significantly affected.

Both the total amount of fat consumed and the faecal crude fat content were higher in high-dose females than in controls. In contrast, the amount of crude fat excreted in the faeces expressed as percentage of the amount of fat consumed ('proportion excreted') was significantly lower in the high-dose females. The faecal content of dry matter, protein, ash and carbohydrate showed no significant intergroup differences, whereas the total amounts of these constituents excreted and, to a lesser extent, their 'proportion excreted' were significantly lower in high-dose females than in controls.

The (calculated) total amount of energy consumed during the 3-day test period was about 10% lower in high-dose females than in controls. This difference was not statistically significant. The energy consumption per kg body weight per day was comparable between the groups fed SSL and controls. The faecal energy excretion (total in 3 days and kcal/kg body weight/day) was signhcantly lower in high-dose females than in controls.

These results do not indicate that the ingestion of diet containing tp to 5% SSL causes loss of energy in the faeces.

Effect levels

1

Key result

Dose descriptor:

NOAEL

Effect level:

2 641 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

female

Basis for effect level:

behaviour (functional findings)

body weight and weight gain

clinical biochemistry

clinical signs

food consumption and compound intake

gross pathology

haematology

histopathology: neoplastic

histopathology: non-neoplastic

immunology

mortality

neuropathology

ophthalmological examination

organ weights and organ / body weight ratios

urinalysis

water consumption and compound intake

2

Key result

Dose descriptor:

NOAEL

Effect level:

2 214 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male

Basis for effect level:

behaviour (functional findings)

body weight and weight gain

clinical biochemistry

clinical signs

food consumption and compound intake

gross pathology

haematology

histopathology: neoplastic

histopathology: non-neoplastic

immunology

mortality

neuropathology

ophthalmological examination

organ weights and organ / body weight ratios

urinalysis

water consumption and compound intake

Target system / organ toxicity

Key result

Critical effects observed:

no

Applicant's summary and conclusion

Conclusions:

The results of this study in Wistar rats did not reveal adverse effects of sodium stearoyl lactylate (SSL) upon administration in the diet at levels up to 5 % (w/w) for one year. Therefore, the No-Observed-Adverse-Effect Level (NOAEL) of SSL under the conditions of this study was set at 5% in the diet, the highest concentration tested. This dietary level was equivalent to 2214 and 2641 mg SSL/kg body weight/day in males and females, respectively.

Executive summary:

The toxicity of the test substance sodium stearoyl lactylate (SSL) was examined in Wistar rats fed diets containing 0, 1.25, 2.5, and 5% SSL for one year, equivalent to mean daily intakes of 558, 1115, and 2214 mg/kg/day in males and 670, 1339, and 2641 mg/kg/day in females, respectively. SSL was well tolerated at these dietary levels as evidenced by the absence of toxicologically significant changes in the general condition and appearance of the rats, survival, neurobehavioural endpoints, growth, feed and water intake, ophthalmoscopic examinations, haematology and clinical chemistry parameters, urinalysis, or necropsy findings. The occurrence of uterine endometrial stromal polyps was the only finding of potential significance. Given the frequent occurrence of these benign tumours in rats, wide variability in the reported incidence of this type of polyps in rats, the lack of statistical significance and lack of biological evidence to suggest a mechanism for the slightly greater incidence in the groups fed 2.5 and 5% SSL, it was concluded that the endometrial stromal polyps observed in females fed SSL were not related to treatment. The no observed adverse effect level (NOAEL) of SSL was placed at 5%, the highest dietary level tested (equivalent to 2214 mg/kg/day for males and 2641 mg/kg/day for females).