Naphthalenesulfonic acid, butyl-, Me derivs., sodium salts

Endpoint summary

Description of key information

No data is available on the product Naphthalenesulfonic acid, methyl, butyl, sodium salt (ANS B) (C7-alkyl naphthalene sulfonate) itself. Evaluation is based on read-across to the comparable C7-alkyl naphthalene sulfonate ANS IP.

The combined repeated dose oral toxicity and reproduction/ developmental toxicity screening test with ANS IP (Naphthalenesulfonic acid, bis(1-methylethyl)-,methyl derivs., sodium salt)in male and female Wistar rats with dose levels of 30, 200, and 500/700 mg/kg body weight resulted to a NOAEL for general toxicity of 30 mg/kg bw/day. The only observed effects at 200 mg/kg bw consisted a slight lower BW in males compared to control (-6%), and an some increased effects in stomach upon histopathological examinations in males.

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

sub-chronic toxicity: oral

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

2017-04-21 to 2018-mm-dd

Reliability:

1 (reliable without restriction)

Justification for type of information:

See chapter 13 for support for read-across within the category of Alkyl Naphthalene Sulfonates (ANS).

Qualifier:

according to guideline

Guideline:

OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)

Deviations:

yes

Remarks:

Based on stability data (Eurofins Munich study no. 166362) the test item and control formulations were prepared at least once every ten days and stored at room temperature and the repetition of homogeneity measurement in the main study was not necessary.

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

Test System
Species/strain: healthy Wistar rats, Crl: WI(Han) (Full Barrier)
Source: Charles River, 97633 Sulzfeld, Germany
Sex: male and female; the female animals were non-pregnant and nulliparous
Age at the start of the treatment period: approx. 14-15 weeks old
Body weight at the allocation of the animals to the experimental groups:
males: 338 - 380 g
(mean: 360.23 g, ± 20 % = 288.18 – 432.27 g)
females: 212 - 254 g
(mean: 234.20 g, ± 20 % = 187.36 – 281.04 g)
The animals were derived from a controlled full-barrier maintained breeding system (SPF). According to the German Act on Animal Welfare the animals were bred for experimental purposes.
This study was performed in an AAALAC-accredited laboratory. According to German animal protection law, the study type has been reviewed and accepted by local authorities. Furthermore, the study has been subjected to Ethical Review Process and was authorised by the Bavarian animal welfare administration.

Housing and Feeding Conditions
- Full barrier in an air-conditioned room
- Temperature: 22 ± 3 °C
- Relative humidity: 55 ± 10 %
- Artificial light, sequence being 12 hours light, 12 hours dark
- Air change: 10 x / hour
- Free access to Altromin 1324 maintenance diet for rats and mice
- Free access to tap water, sulphur acidified to a pH of approximately 2.8 (drinking water, municipal residue control, microbiological controls at regular intervals)
- Animals were housed in groups of 5 animals / sex / cage in type IV polysulphone cages or in double decker IVC cages during the premating period for both males and females and during post-mating period for males depending on the mating status. During mating period males and females were housed together in ratio 1:1 (male to female). After the confirmation of mating, females were kept individually during gestation/lactation period in type III H, polysulphone cages and males were returned to their original cage. In each cage Altromin saw fibre was used as bedding.
- Nesting material were provided latest on GD 18 for all mated females
- Certificates of food, water and bedding are filed for two years at BSL Munich and afterwards archived at Eurofins Munich
- Adequate acclimatisation period (at least 5 days) under laboratory conditions

Preparation of the Animals
Prior to the start of the treatment period a detailed clinical observation outside the home cage was made. None of the animal showed pathological signs before the first administration.
Before dosing all females were screened for two weeks for regular estrous cyclicity and animals (10 females/ group) with regular estrous cycle (4-5 day cycle) were used in the study.
Before the first administration all animals to be used for the study were weighed and assigned to the experimental groups with achieving a most homogenous variation in body weight throughout the groups of males and females, respectively. Randomisation was performed with validated IDBS Workbook 10.1.2 software.
Each animal was marked with its identification number by individual ear tattoo or tail marking.

Route of administration:

oral: gavage

Vehicle:

other: sterile water

Remarks:

Manufacturer: AlleMan Pharma, Batch No.: 601101, 511535, 605070, 612118, Expiry Date: 12/2018 (601101), 10/2018 (511535), 04/2019 (605070), 11/2019 (612118)

Details on oral exposure:

According to the results of the dose range finding study (BSL Munich study no. 163485) and in consultation with the sponsor the following doses were selected for the three dose groups (LD = low dose, MD = medium dose, HD = high dose) and one control group (C). The animals were treated with the test item formulation or vehicle on 7 days per week for a maximum period of 63 days in females, i.e. during 14 days of pre-mating and maximum 14 days of mating in both males and females, during the gestation period and up to post-natal day 12 in females. Males were dosed after the mating period until the minimum total dosing period of 28 days was completed.

Control: 0 mg/kg/d
Low Dose: 300 mg/kg/d
Medium Dose: 200 mg/kg/d
High Dose: 700 mg/kg/d
High Dose*: 500 mg/kg/d
* = the high dose level was reduced from 700 mg/kg bw to 500 mg/kg bw after 6 or 7 days of dose application initiation (staggered start of dosing) due to overt toxicity.

The highest dose level was chosen with the aim of inducing toxic effects, but no death or severe suffering. Thereafter, a descending sequence of dose levels was selected with a view to demonstrate any dosage related response and NOAEL.
The animals in the control group were handled in an identical manner to the test group subjects and received the vehicle using the same volume as used for the high dose group.


The test item and vehicle were administered daily as single doses to the animals by oral gavage. The application volume for all groups was 5 mL/kg body weight. For each animal the individual dosing volume was calculated on the basis of the body weight most recently measured.

Analytical verification of doses or concentrations:

yes

Remarks:

During the study samples were collected for the investigation of substance concentration.

Details on analytical verification of doses or concentrations:

Samples were taken from the middle of prepared formulations from all dose groups and from the middle of the control group in study week 1 (pre-mating period), 3 (first week of mating), 5 (gestation) and in the last week of the study (gestation / lactation) from all groups (16 samples).
Each sample taken during the study was retained in duplicate (sample A, sample B, each of at least 5 mL). The A-samples were analysed at Eurofins Munich and until then stored under appropriate conditions based on available stability data (Eurofins Munich Study No. 166362). The procedures followed for the study sample analysis were mentioned in a phase plan (study no. 166363) that was amended to the study plan. The B-samples were retained at -15 to -35 °C at BSL Munich (test facility) and discarded after completion of the final study report. The results were reported in the appendix of the final report.

Duration of treatment / exposure:

The animals were treated with the test item formulation or vehicle on 7 days per week for a maximum period of 63 days in females, i.e. during 14 days of pre-mating and maximum 14 days of mating in both males and females, during the gestation period and up to post-natal day 12 in females. Males were dosed after the mating period until the minimum total dosing period of 28 days was completed.

Frequency of treatment:

Daily

Dose / conc.:

0 mg/kg bw/day (nominal)

Dose / conc.:

30 mg/kg bw/day (nominal)

Dose / conc.:

200 mg/kg bw/day (nominal)

Dose / conc.:

700 mg/kg bw/day (nominal)

Remarks:

the high dose level was reduced from 700 mg/kg bw to 500 mg/kg bw after 6 or 7 days of dose application initiation (staggered start of dosing) due to overt toxicity

No. of animals per sex per dose:

100 animals (40 males and 60 females) were included in the study. All females were screened for regular estrous cycles for 14 days before the treatment initiation and only 40 females (10 females/group) showing regular estrous cycles were continued in the study.

Control animals:

yes, concurrent vehicle

Observations and examinations performed and frequency:

Clinical Observations
General clinical observations were made at least once a day, preferably at the same time each day. The health condition of the animals was recorded. Twice daily all animals were observed for morbidity and mortality except on weekends and public holidays when observations were made once daily.
Once before the first exposure, and at least once a week thereafter, detailed clinical observations were made in all animals outside the home cage in a standard arena. Clinical observations included spontaneous activity, lethargy, recumbent position, convulsions, tremors, apnoea, asphyxia, vocalisation, diarrhoea, changes in the skin and fur, eyes and mucous membranes (salivation, discharge), piloerection and pupil size. Changes in gait, posture, response to handling as well as the presence of clonic or tonic movements, stereotypes, difficult or prolonged parturition or bizarre behaviour were recorded.
During the study all animals were visually monitored to see if there is condition of polydipsia.

Functional Observations
Multiple detailed behavioural observations were made in the week before the first treatment and during the last week of the treatment in 5 randomly selected males and during the last week of lactation of the lactation period in 5 randomly selected females (only lactating females were evaluated) of each group outside the home cage using a functional observational battery of tests.
Sensory reactivity to different modalities, grip strength and motor activity assessments and other behavioural observations as well as rearing supported and not supported, urination, defecation, startle/ auditory response, equilibrium reflex, positional passivity, visual placing, fore and hind limb grip strength, tail pinch response, toe pinch reflex, extensor thrust/limb tone, hind limb reflex, righting reflex on the ground, air righting reflex, pupil response, body temperature and ophthalmoscopy (anterior chamber of the eye and fundus of eye).

Body Weight and Food Consumption
The animals were weighed once before the assignment to the experimental groups, on the first day of dosing and weekly thereafter as well as at the end of the study. During pregnancy, females were weighed on gestation days (GD) 0, 7, 14 and 20 and within 24 hours of parturition (day 0 post-partum), on PND 4 and PND 13 along with pups. All animals were weighed directly before termination.
Food consumption was measured on the corresponding days of the body weight measurements after the beginning of the dose administration. Food consumption was not measured during the mating period in males and females and the post-mating period in males.
Individual food consumption was calculated based on survival of animals on each day during two food measurement intervals. Factor was derived for that particular period and total cage consumption was divided by factor (e.g. for male cage 1 during premating day 1-7, factor was 4.67) to get food consumption per animal for that particular period.

Haematology
Haematological parameters were examined in 5 randomly selected males and females (only lactating females were evaluated) from each group at the end of the treatment prior to or as part of the sacrifice of the animals. Blood from the abdominal aorta of the animals was collected in EDTA-coated tubes. The following haematological parameters were examined:
haematocrit value (Hct), haemoglobin content (Hb), red blood cell count (RBC), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), reticulocytes (Re), platelet count (PLT), white blood cells (WBC), neutrophils (Neu), lymphocytes (Lym), monocytes (Mono), eosinophils (Eos), basophils (Baso) and large unstained cells (Luc).

Blood Coagulation
Coagulation parameters from 5 randomly selected males and females (only lactating females were evaluated) of each group were examined at the end of the treatment prior to or as part of the sacrifice of the animals. Blood from the abdominal aorta of the animals was collected in citrate tubes. The following coagulation parameters were examined: prothrombin time (PT) and activated partial thromboplastin time (aPTT).

Clinical Biochemistry
Parameters of clinical biochemistry from 5 randomly selected males and females (only lactating females were evaluated) of each group were examined at the end of the treatment prior to or as part of the sacrifice of the animals. Blood from the abdominal aorta of the animals was collected in serum separator tubes. The following parameters of clinical biochemistry were examined:
alanine aminotransferase (ALAT), aspartate-aminotransferase (ASAT), alkaline phosphatase (AP), creatinine (Crea), total protein (TP),
albumin (Alb), urea, total bile acids (TBA), total cholesterol (Chol), glucose (Gluc), sodium (Na) and potassium (K).
From 2 female pups/litter on day 4 after birth from all dams and 2 pups/litter at termination on day 13 and from all adult males at termination, blood samples were collected from the defined site in serum separator tubes. All blood samples were stored under appropriate conditions. Blood samples from the day 13 pups and the adult males were assessed for serum levels for thyroid hormones (T4).
Further assessment of T4 in blood samples from the main study dams and day 4 pups was not deemed necessary. Additionally, assessment of TSH in day 4 pups, adult females, day 13 pups, and adult males were not considered necessary based on the fact that no histopathological findings were observed in thyroid/parathyroid gland of selected male and female adult animals and T4 hormone levels of males and day 13 pups. Pup blood was pooled by litter for thyroid hormone analysis.
Two pups per litter were sacrificed on day 4 after birth and blood samples were taken for possible serum hormone assessments. The two pups per litter were female pups to reserve male pups for nipple retention evaluations. No pups were eliminated where litter size dropped below 8 pups. When there was only one pup available above a litter size of 8, only one pup was sacrificed on PND 4.

Urinalysis
A urinalysis was performed with samples from 5 randomly selected males and females (only lactating females were evaluated) prior to or as part of the sacrifice of the animals. Additionally, urine colour/ appearance was recorded. The following parameters were measured using qualitative indicators (Henry Schein Urine Stripes URI 10SL): specific gravity, nitrite, ph-value (pH), protein, glucose, ketone bodies (ketones), urobilinogen (ubg), bilirubin, blood and leukocytes.

Sacrifice and pathology:

Pathology
All surviving males were sacrificed any time after the completion of the mating period (after a minimum dosing period of 28 days) and females were sacrificed on the respective PND 13 by using anesthesia (ketamine/xylazine). Vaginal smears were examined on the day of necropsy to determine the stage of estrous cycle.
Non-pregnant females were sacrificed on study day 26 using the sperm-positive vaginal smear as an evidence of mating.
All animals were subjected to a detailed gross necropsy which included careful examination of the external surface of the body, all orifices and the cranial, thoracic and abdominal cavities and their contents.
Special attention was paid to the organs of the reproductive system. The ovaries, uterus with cervix, vagina, testes, epididymides, accessory sex organs (prostate, seminal vesicles with coagulating glands as a whole), the thyroid/parathyroid glands and all organs showing macroscopic lesions of all adult animals were preserved in 4 % neutral-buffered formaldehyde, except for testes and epididymides which were preserved in modified Davidson’s Solution for 24 hours and then transferred to 70 % ethanol.
The number of implantation sites and corpora lutea was recorded for each parental female at necropsy. The number of corpora lutea and implantation sites was recorded for any females sacrificed 26 days after the end of the mating period with no evidence of mating and for any females sacrificed on day 26 post-coitum due to non-delivery.

Organ Weights
The wet weight of the organs [testes (paired weight), epididymides (paired weight), prostate, seminal vesicles and coagulating glands (complete weight), uterus with cervix, ovaries (paired weight), thyroid/parathyroid glands (from 1 pup/sex/litter/group and from all adult males and females) – weighed after fixation (complete weight), thymus, liver, spleen, kidneys (paired weight), brain, adrenal (paired weight), heart and pituitary gland] of 5 randomly selected male and female animals (only lactating females were evaluated) from each group was recorded as soon as possible. Paired organs were weighed together. Organ weights of animals found dead were not recorded. Reproductive organs were weighed in all animals.
Thyroid/parathyroid glands from all adult males and females were preserved. Weight of thyroid/parathyroid glands was measured after fixation.

Adrenal glands, all gross lesions, aorta, brain (incl. medulla/pons, cerebellar and cerebral cortex), caecum, colon, duodenum, epididymides, eyes, Harderian glands, femur with knee joint, heart, ileum (including Peyer´s patches), jejunum, kidneys, liver, lungs, lymph nodes (mandibular), lymph nodes (mesenteric), lymph nodes (axillary), mammary gland area (male and female), oesophagus,optic nerves, ovaries, oviducts, pancreas, pituitary, prostate and seminal vesicles with coagulating glands as a whole, rectum, salivary glands (sublingual, submandibular), sciatic nerve, skeletal muscle, skin, spinal cord (cervical, thoracic and lumbar segments), spleen, sternum (with bone marrow), stomach, testes, thymus, thyroid/parathyroid glands, tongue, trachea, ureters, urinary bladder, uterus with cervix and vagina of the same selected animals from each group were preserved in 4% neutral-buffered formaldehyde except for eyes, testes and epididymides that were fixed in Modified Davidson’s Fixative for approximately 24 hours before they were transferred to 70% ethanol. All animals found dead and/or intercurrently euthanised for animal welfare reasons were subjected to a gross necropsy and the organs preserved for a histopathological examination.
Thyroid/parathyroid glands from non-selected adult animals were preserved for potential histopathological examination. The thyroid gland weight was measured after fixation.


Histopathology
A full histopathology was carried out on the preserved organs and tissues of the selected animals of the control and high dose groups which were sacrificed at the end of the treatment period. Evaluation of thyroid/parathyroid glands from pups and from the remaining non-selected adult animals was not deemed necessary as no test item related histopathological findings were observed in thyroid/parathyroid gland of selected animals and there was also no test item related effect observed on T4 hormone level in males and pups sacrificed on PND 13. A full histopathology was carried out on the preserved organs and tissues of all animals which died during the study.
Testes, epididymides, ovaries, uterus with cervix, vagina, accessory sex organs (prostate, seminal vesicle with coagulating gland) were trimmed, embedded into paraffin, cut at an approximated thickness of 2-4 µm and stained with hematoxylin and examined in control and HD animals and in non-pregnant female animals of the LD and MD animals. Testes, epididymides and accessory sex organs (prostate, seminal vesicle with coagulating gland) were also examined in the mating partners of the non-pregnant female LD and MD animals.
These examinations were extended to animals of all other dosage groups for treatment-related changes observed in the high dose group for stomach, liver and kidney. Only organs and tissues of the other dosage groups showing changes in the high dose group were examined.
Any gross lesion macroscopically identified was examined microscopically in all animals. Discoloration possibly due to the test item was evaluated in the organs of all dose groups.
For the testes, a detailed qualitative examination was made; taking into account the tubular stages of the spermatogenic cycle at evaluation of additional hematoxylin-PAS (Periodic Acid Schiff) stained slides.
The histological processing of tissues to microscope slides was performed at the GLP-certified contract laboratory AnaPath GmbH, AnaPath Services, Hammerstrasse 49, 4410 Liestal, Switzerland (test site for tissue processing). The histopathological evaluation was performed at the GLP-certified contract laboratory AnaPath GmbH, AnaPath Services, Hammerstrasse 49, 4410 Liestal, Switzerland (test site for histopathology). The study phases from test site 1 and 2 were performed in compliance with the Swiss Ordinance relating to Good Laboratory Practice adopted 18 May 2005 [SR 813.112.1] (Status as of 01 December 2012). Blocking, embedding, cutting, H&E staining and scientific slide evaluation were performed according to the corresponding SOP’s of the test sites.
The principal investigator for histopathological tissue processing sent all raw data (including blocks, slides, paper raw data, statement of compliance and quality assurance statement) to the study director.
The principal investigator for histopathological evaluation provided the histopathology results to the study director by e-mail and sent a pathology phase report to the study director upon the completion of the study.

Statistics:

A statistical assessment of the results of body weight, food consumption, parameters of haematology, blood coagulation and clinical biochemistry were performed for each gender by comparing values of dosed with control animals using a one-way ANOVA and a post-hoc Dunnett Test. Results of absolute and relative organ weights were statistically analyzed by comparing values of dosed with control animals using either a parametric one-way ANOVA and a post-hoc Dunnett Test or a non-parametric Kruskal-Wallis Test and a post-hoc Dunn’s Test, based on the results of homogeneity and normality tests. These statistics were performed with GraphPad Prism V.6.01 software or Ascentos 1.1.3 software (p<0.05 was considered as statistically significant).

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

see Details on results

Mortality:

mortality observed, treatment-related

Description (incidence):

see Details on results

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

see Details on results

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

see Details on results

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

no effects observed

Description (incidence and severity):

see Details on results

Clinical biochemistry findings:

effects observed, non-treatment-related

Description (incidence and severity):

see Details on results

Urinalysis findings:

effects observed, non-treatment-related

Description (incidence and severity):

see Details on results

Behaviour (functional findings):

effects observed, non-treatment-related

Description (incidence and severity):

see Details on results

Organ weight findings including organ / body weight ratios:

effects observed, non-treatment-related

Description (incidence and severity):

see Details on results

Gross pathological findings:

effects observed, non-treatment-related

Description (incidence and severity):

see Details on results

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

see Details on results

Histopathological findings: neoplastic:

not examined

Other effects:

no effects observed

Description (incidence and severity):

see Details on results

Details on results:

Clinical Observations
In terminally sacrificed males, predominant clinical signs observed during the treatment period (premating day 1 to mating/post mating day 14) were moderately increased salivation in one animal of MD and moving the bedding in two animals of MD group during very few days of mating and postmating period. In HD group, major clinical signs observed were slight to moderately reduced spontaneous activity, half eyelid closure, moving the bedding, slight to moderate salivation and piloerection in all animals during majority of premating and mating/postmating period.
In terminally sacrificed females, major clinical signs observed during the treatment period (Premating day 1 to PND 12) were moving the bedding on one day during lactation period in one female of LD group, moving the bedding, slightly to moderately increased salivation in few animals on few days of MD group and moving the bedding, slightly to severely increased salivation, slightly to moderately increased piloerection, reduced spontaneous activity, half eyelid closure in all animals on majority of days during treatment period in HD group.
Isolated incidences of alopecia on various body parts, abnormal breathing and nasal discharge was observed on few occasions in one each female animal of MD group and considered to be incidental in nature.
 
The clinical signs salivation and moving the bedding were observed immediately after the dose administration and therefore were considered to be a sign of discomfort due to a local reaction to the test item rather than a systemic adverse effect and has no toxicological relevance. However, clinical signs like slightly to moderately increased piloerection, reduced spontaneous activity and half eyelid closure in HD group could be attributed to treatment with the test item.
None of the females showed signs of abortion or premature delivery.
During the weekly detailed clinical observation, no relevant differences between the groups were found.

Mortality
During the treatment period of this study, few mortalities were observed as follows:
- Male no. 31 (HD) was found dead on premating day (PMD) 6. Clinical signs observed before death were spontaneous activity reduced (moderate), piloerection (moderate), half eyelid closure during PMD 2-6 and moving the bedding during PMD 5-6.
- Male no. 35 (HD) was found dead on premating day (PMD) 6. Clinical signs observed before death were slight increased salivation on PMD 1, moving the bedding from PMD 1-6 and moderately reduced spontaneous activity, moderate piloerection and half eyelid closure during PMD 2-6.
- Male no. 38 (HD) was found dead on premating day (PMD) 5. No specific clinical signs were observed before death.
- Female no. 75 (HD) was found dead on premating day (PMD) 3. Clinical signs observed before death were moderately reduced spontaneous activity, moderate piloerection and half eyelid closure during PMD 2-3.
- Female no. 77 (HD) was found dead on premating day (PMD) 5. Clinical signs observed before death were moderately increased salivation on PMD 3, moving the bedding during PMD 3-5 and slightly increased salivation during PMD 4-5.
Histopathologically, in females, gastric changes (ulceration in female No. 75 and erosion in female No. 77) contributed to both morbidity and mortality. In males, based on the histopathology investigation, the cause of death was not evident although, there were slight to moderate gastric changes were observed which might have contributed to the morbidity.

Body Weight Development
In males, there was no statistically significant difference observed on body weight between the LD and the control group during the entire study period. However, lower group mean body weights from premating day 14 to terminal sacrifice were observed in MD group without achieving statistical significance when compared with the controls. A statistically significantly lower group mean body weight was also observed in HD group from day 7 during entire study period although statistical significance was achieved only on premating day 7, 14 and mating/postmating day 7 when compared with the controls.
In correlation to body weight, group mean body weight gain was statistically significantly lower during mating/post mating day 7-14, premating day 1-mating/postmating day 14 and premating day 1 to terminal sacrifice in MD group males when compared with the controls. There was also statistically significantly lower group mean body weight gain observed during premating day 1-7, premating day 1 to mating/postmating day 14, premating day 1 to terminal sacrifice and statistically significantly higher group mean body weight gain during premating day 7-14 and mating/postmating day 7-14 in HD group when compared with the controls.
In females, no statistically significant difference in group mean body weight was observed in treatment groups during entire study period when compared with controls. There was statistically significantly higher group mean body weight gain observed during premating day 7-14 in HD group when compared with the controls.
This statistically and biologically significant effect on body weight and body weight gain in MD and HD group male was considered as test item related and toxicologically relevant. However, statistically significant effect on female group mean body weight gain in HD group was attributed to possible compensatory recovery after the reduction of dose from second week of the study.

Food Consumption
In males, the food consumption during treatment period tended to increase with the progress of the study in the control, the LD, the MD and the HD group. However, In HD group, during premating day 1-7, food consumption was lower without achieving statistical significance compared to the control group and this effect on food consumption in males was considered to be test item related.
In females, no statistically significant effect on food consumption was observed during premating period, gestation and lactation period in treatment groups when compared with the controls. However, in correlation to body weight development, marginally lower food consumption was observed in HD females during premating day 1-7 when compared with the controls. As this effect on female food consumption was marginal and in the light of no significant effect on body weight development, this effect on food consumption in females was not considered to be adverse.

Haematology and Coagulation
In males sacrificed at the end of treatment period, no test item related adverse effects were observed for haematological parameters. However, there was a statistically significantly higher platelets (PLT) count observed in HD group compared to the control group. All group mean and most of the individual values were within the historical control data range. As group mean value was within historical control data limit, statistically significant effect on PLT in HD group was considered to be incidental and not related to the treatment with test item. No test item related effect was observed on coagulation parameters when compared with the controls.
In females sacrificed at the end of treatment period, no statistically significant or test item effect observed on any of the haematology or blood coagulation parameters when compared with the controls. All group mean and most of the individual values were within the historical control data range.

Clinical Biochemistry
In males sacrificed at the end of treatment period, significantly lower total bile acids (TBA) was observed in MD and HD group although statistical significance In males and females sacrificed at the end of treatment period, no test item related or statistically significant effect on any clinical biochemistry parameter in treatment groups was observed when compared with the control. There was higher TBA group mean value observed in female LD group without achieving statistical significance. Due to lack of dose dependency and consistency, this effect on TBA in LD group was not considered to be test item related and toxicologically relevant.

Urinanalysis
The urinalysis performed in selected male and female animals sacrificed at the end of treatment period revealed no test item treatment related effect and all urinary parameters were in the normal range of variation. High protein levels were found in the urine of few male and females of all groups including control group. Therefore, this effect on urine parameters was not considered to be test item related.

Functional Observations
In males, no relevant effects were observed in any of the parameters of the functional observation battery before and at the end of the treatment period except incidental statistically significantly higher defecation count before the initiation of treatment in LD group when compared with the controls. There were no biologically relevant differences observed in body temperature between the groups.
In females, statistically significantly higher supported rearing count in MD, lower supported rearing count in LD, MD and HD and statistically significantly lower not supported rearing count in all treatment groups was observed before initiation of the treatment which was not considered to be toxicologically relevant. There was also statistically significantly higher supported rearing count in LD and HD group, statistically significantly lower urination count in all treatment groups and statistically significantly lower defecation count in LD group observed during last week of treatment. As this type of difference was marginal and without dose dependency/consistency, it has no toxicological relevance and could be considered as biological variation. There were no biologically relevant differences in body temperature between the groups except statistically significantly lower body temperature was observed before initiation of the treatment in LD group which was considered to be toxicologically irrelevant.

Organ Weights
In males sacrificed at the end of treatment period, there were statistically significantly higher absolute liver weights in all treatment groups (except MD group), higher relative (to body weight) liver weights in MD and HD group and higher kidney weights in LD and HD group although statistical significance only achieved in LD group when compared with the controls. Increased liver absolute weights were histologically correlated with slight hepatocellular hypertrophy only in one animal from the HD group, whereas in the MD and LD group neither the absolute nor the relative increase in liver weight correlated with underlying histological changes. Therefore, without a dose dependent correlation between liver weight increase and the observed histopathological hepatic changes and in absence of hepatic-derived enzyme profiling, the toxicological relevance of the liver weight increase could not be established.
In females sacrificed at the end of treatment period, significantly higher absolute liver weights were observed in HD group when compared with the controls although statistical significance was not achieved. There were also statistically significantly higher relative (to body weight) kidney weights observed in HD group when compared with the controls. In females, statistically significantly higher relative kidney weights in HD group were considered of no toxicological relevance in absence of correlating histological changes.

Pathology
Few specific macroscopic changes were recorded for the male and female animals, which based on microscopic examination were not considered to be of test item treatment relevance.
The macroscopic changes observed were lung- dark red discolouration (male no. 35 and 38 of HD group), thymus - red discolouration (male no. 35 and 38 of HD group), stomach - gas filled (male no. 31 if HD group, female no. 77 of HD group), Intestinal tract- gas filled (male no. 31, 35, 38 of HD group, female no. 77 of HD group), left testes- absent (male no. 21 of MD group), testes- small (male no. 14 of LD group), left epididymides- small (male no. 14 of LD group and male no. 21 of MD group), right kidney- dilatation (male no. 30 of MD group), lung- dark abnormal colour (female no. 75 of HD group) and liver- diaphragmal herniation (female no. 59 of LD group)
Macroscopic findings correlating with histopathological observations were observed in following animals: 
- In decedents, red discoloration observed in the thymus of males no. 35 and No. 38 of HD group was correlated microscopically with congestion and hemorrhage in male no. 35 and with hemorrhage in male no. 38. The above mentioned changes were considered incidental agonal changes which are occasionally found in animals being subjected to necropsy. All other changes recorded at necropsy in decedents were considered incidental and most likely associated with autolytic processes.
- In survivors, small testes and epididymides recorded in male no. 14 (LD group) correlated microscopically with testis and epididymis atrophy and aspermia. This changes were considered to be most likely incidental.
In male No. 21 (MD group) small epididymis on the left side was correlated microscopically with unilateral epididymis atrophy and aspermia. The above mentioned changes were considered to be most likely incidental. In addition, in the male no. 30, a dilated right kidney was correlated microscopically with pelvic dilatation. All observed changes in male no. 30 were considered to be most likely incidental.
In female No. 59 (LD group), the observed diaphragmal herniation corresponded histologically to a hepatic nodule. This liver change was to be considered incidental.
All other changes recorded at necropsy in surviving animals were considered incidental and most likely associated with autolytic processes. In absence of corresponding histopathological findings, these necropsy findings were considered to be of no toxicological relevance.


Histopathology
Under the conditions of this study, there were a number of early decedents. In females, gastric changes (ulceration in female No. 75 and erosion in female No. 77) contributed to both morbidity and mortality. In males (31, 35 and 38) based on the histopathology investigation, the cause of death was not evident although, there were slight to moderate gastric changes were observed which might have contributed to the morbidity.
In decedents, test item related histopathology changes observed in stomach of females were ulceration (animal No. 75) and multifocal erosions (animal No. 77). The above mentioned changes were associated with vacuolization of forestomach epithelial cells (epithelial vacuolization), hyperkeratosis, mixed cell infiltrates and squamous hyperplasia. In male stomach, hyperkeratosis and squamous hyperplasia were observed. In liver minor degree of hepatocytes vacuolation (fatty change) and centrilobular hypertrophy was observed in few males and females.
In survivors of LD, MD and HD groups, test item related histopathology changes were observed in liver, kidney and stomach.
In liver, minor degree of centrilobular hepatocytes hypertrophy was observed only in few males from the HD group and was considered test item related. Further, minimal to moderate glycogen accumulation was observed in some males and females form the HD group only, whereas in control animals moderate glycogen accumulation was also observed in one female. The above mentioned changes were considered to be most likely incidental (related to the feeding schedule), whereas a test item contribution cannot be fully excluded. In addition, in one female from the low dose group, a slight bile duct hyperplasia, slight fibrosis and a hepatic nodule (hepatodiaphragmatic herniation) was observed and correlated with the liver herniation through the diaphragm recorded at necropsy. These findings were considered incidental and deemed not test item related.
In kidney, minimal to slight hyaline droplets accumulation in tubular epithelial cells were observed in the majority of males from all dose groups and the control group. This renal change is a male rat specific phenomenon of no toxicological relevance in humans. Minimal to slight tubular basophilia was observed in few animals from the high dose group only. The tubular basophilia was considered most likely related to the test item administration. Minimal to slight tubular simple dilatation was observed in some male and females from all dose groups and in one female from the control group. The tubular simple dilatation was considered most likely incidental. Furthermore, pelvic dilatation was observed in one female from the low dose group and two males from the mid dose group. These changes were deemed incidental and not treatment related.
In stomach, moderate forestomach ulceration accompanied by severe multifocal mixed cell infiltrates, moderate submucosal edema wall and epithelial vacuolization was observed in one male from the MD group. Minimal to moderate mixed cell infiltrates mainly located at the limiting ridge and sometimes extending in the adjacent forestomach and glandular stomach submucosa of males and females from the LD and MD groups and only in males from the HD group. Minimal to moderate epithelial vacuolization was noticed in few males from LD, MD and HD dose groups only. Furthermore, a minor degree of hyperkeratosis was observed in some males from the LD and HD dose groups, whereas slight to moderate squamous hyperplasia was present only in few males from the HD group. These changes in stomach were considered to be most likely related to the test item administration.
The test item did not produced any histological evidence of toxicity in the reproductive organs and tissues including testes, epididymides, prostate gland, seminal vesicles, coagulating glands, ovaries, oviducts, uterus and cervix, and vagina. Further, there were no treatment-related effects on the testicular histomorphology including spermatogenesis and interstitial cell structure.
In one male from the low dose group (male no. 14) atrophy of the testis and epididymis was observed, while in one male from the mid dose group (male no. 21) epididymis atrophy was noticed. In absence of any toxicologically significant changes in the male reproductive organs/tissues of survivors, the above mentioned changes were considered incidental.
Further, the treatment with test item did not induced histomorphological effects in the reproductive organs of the non-pregnant female from the low dose group (Animal No. 54). The infertility was caused by the testicular atrophy and subsequent aspermia observed in its mating partner male no. 14.
In conclusion, due to the early mortality observed in males and females from the high dose group and the presence of several histopathological adverse changes in different organs, a histomorphological NOAEL (no observed adverse level) could be established at 30 mg/kg bw/day for the male rats and 200 mg/kg bw/day for female rats.



 

Key result

Dose descriptor:

NOAEL

Effect level:

30 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

UVCB substance with 100% purity

Sex:

male/female

Basis for effect level:

histopathology: non-neoplastic

Key result

Dose descriptor:

LOAEL

Effect level:

200 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks:

UVCB substance with 100% purity

Sex:

male/female

Basis for effect level:

histopathology: non-neoplastic

Remarks on result:

other:

Remarks:

Close examination shows that the only effects observed at MD (200 mg/kg) are a slight lower BW compared to control (-6%) in males, and a limited increase in the combined effects in stomach upon histopathological examinations in males and females.

Key result

Critical effects observed:

yes

Lowest effective dose / conc.:

30 mg/kg bw/day (nominal)

System:

gastrointestinal tract

Organ:

stomach

other: Additionally, slight effect on BW males

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

yes

Key result

Critical effects observed:

yes

Lowest effective dose / conc.:

200 mg/kg bw/day (nominal)

System:

urinary

Organ:

kidney

liver

other: At higher dose levels the local effects in stomach are most prominent, possibly causing mortaility to occur (at 700 mg/kg bw/day)

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

yes

Conclusions:

The combined repeated dose oral toxicity and reproduction/ developmental toxicity screening test with Naphthalenesulfonic acid, bis(1-methylethyl)-,methyl derivs., sodium salt in male and female Wistar rats with dose levels of 30, 200, and 500/700 mg/kg body weight resulted to a NOAEL for general toxicity in male of 30 mg/kg bw/day and for general toxicity in female of 200 mg/kg bw/day.

Executive summary:

The aim of this study was to assess the possible effects ofNaphthalenesulfonic acid, bis(1-methylethyl)-,methyl derivs., sodium salton male and female fertility and embryofoetal development after repeated doseadministrationinWistarrats.

The test item was administered daily in graduated doses to 3 groups of test animals, one dose level per group for a treatment period of 63 days, i.e. during 14 days of pre-mating and maximum 14 days of mating in both males and females, during the gestation period and up to post-natal day 12 in females. Males were dosed after the mating period until the minimum total dosing period of 28 days were completed. Animals of an additional control group were handled identically as the dose groups but receivedaqua ad iniectabilia(sterile water), the vehicle used in this study.The 4 groups comprised 10 male and 10 femaleWistarrats.Before dosing all females were screened for two weeks for regular estrous cyclicity and animals (10 females/ group) with regular estrous cycle (4-5 day cycle) were used in the study.

The following doses were evaluated:

Control:          0   mg/kg bw/day

Low Dose:      30  mg/kg bw/day

Medium Dose:200mg/kg bw/day

High Dose:     700mg/kg bw day / 500 mg/kg bw/day*

* = the high dose level was reduced from 700 mg/kg bw to 500 mg/kg bw after 6 or 7 days of dose application (staggered start of dosing) due to overt toxicity.

The test item formulation was prepared once in 10 days based on stability data. The test item was dissolved inaqua ad iniectabiliaand administered daily during14 days of pre-mating and 14 days of mating in both male and female animals, during the gestation period and up to post-natal day 12 in females. Males were dosed for28 days. Dose volumes were adjusted individually based on weekly body weight measurements. Theadministrationvolumewas 5 mL/kg bodyweight.

During the period of administration, the animals were observed each day for signs of toxicity. Animals that died were examined macroscopically and at the conclusion of the test, surviving animals were sacrificed and observed macroscopically.

Body weight and food consumption were measured weekly, except for food consumption measurements which were not taken during the mating period in female animals and the mating and post-mating period in male animals.

Haematological and clinical biochemistry evaluations were performedon blood samples collected at terminal sacrifice fromfive randomly selected males and females from each group. Urinalysis wasperformedon samples collected at terminal sacrifice fromfive randomly selected males from each group.

Functional observations including sensory reactivity to different stimuli, grip strength, motor activity assessments and other behavior observations were performed in the week before the treatment from all animals and in the last week of treatment infive randomly selected males and femalesof each group.

After 14 days of treatment to both male and female, animals were mated (1:1) for a maximum of 14 days. The subsequent morning onwards the vaginal smears of females were checked to confirm the evidence of mating. After the confirmation of the mating, females were separated and housed individually. Blood samples from the adult males were assessed for serum levels for thyroid hormones (T4). Further assessment of T4 in blood samples from adult females were not deemed necessary.

The males were sacrificed after completion of the mating period on treatment day 29 and the females along with their pups were sacrificed on post natal day 13. Non-pregnant females were sacrificed on day 26.

A full histopathological evaluation of the preserved tissues was performed on high dose and control animals, in non pregnant female animals and male mating partners of the LD and MD animals. These examinations were extended to animals of all other dosage groups as treatment-related changes were observed in the high dose group forstomach, liver and kidney. For the testes, a detailed qualitative examination was made taking into account the tubular stages of the spermatogenic cycle at evaluation ofadditional hematoxylin-PAS (Periodic Acid Schiff)stained slides.All gross lesions macroscopically identified were examined microscopically in all animals.

Summary Results

Mortality:

During the treatment period of this study,fewmortalities observed were male nos. 31, 35 (HD) found dead on premating day (PMD) 6, male no. 38 (HD) was found deadon premating day (PMD) 5, female no. 75 (HD) was found dead on premating day (PMD) 3 and female no. 77 (HD) was found dead on premating day (PMD) 5.Histopathologically,in females, gastric changes (ulceration in female No. 75 and erosion in female No. 77) contributed to both morbidity and mortality. In males, based on the histopathology investigation, the cause of death was not evident although, there were slight to moderate gastric changes were observed which might have contributed to the morbidity.

Clinical Observations:

In terminally sacrificed males, predominant clinical signs observed during the treatment period (premating day 1 to mating/post mating day 14) were moderately increased salivation in one animal of MD and moving the bedding in two animals of MD group during very few days of mating and postmating period. In HD group, major clinical signs observed were slight to moderately reduced spontaneous activity, half eyelid closure, moving the bedding, slight to moderate salivation and piloerection in all animals during majority of premating and mating/postmating period

In terminally sacrificed females, major clinical signs observed during the treatment period (Premating day 1 to PND 12) were moving the bedding on one day during lactation period in one female of LD group, moving the bedding, slightly to moderately increased salivation in few animals on few days of MD group and moving the bedding, slightly to severely increased salivation, slightly to moderately increased piloerection, reduced spontaneous activity, half eyelid closure in all animals on majority of days during treatment period in HD group.

The clinical signs salivation and moving the bedding were observed immediately after the dose administration and therefore were considered to be a sign of discomfort due to a local reaction to the test item rather than a systemic adverse effect and has no toxicological relevance. However, clinical signs likeslightly to moderately increased piloerection, reduced spontaneous activity and half eyelid closure in HD group could be attributed to treatment with the test item.

None of the females showed signs of abortion or premature delivery. During the weekly detailed clinical observation, no relevant differences between the groups were found.

Functional Observations:

In males and females, no relevant effects were observed in any of the parameters of the functional observation battery before and at the end of the treatment period except incidental statistically significantly higher/lower count for few parameters before the initiation of treatment or at the end of treatment when compared with the controls. There were no biologically relevant differences observed in body temperature between the groups.

Body Weight Development:

In males, there was no statistically significant difference observed on body weight between the LD and the control group during the entire study period. However, lower group mean body weights from premating day 14 to terminal sacrifice were observed in MD group without achieving statistical significance when compared with the controls. A statistically significantly lower group mean body weight was also observed in HD group from day 7 during entire study period although statistical significance was achieved only on premating day 7, 14 and mating/postmating day 7 when compared with the controls.

In correlation to body weight, group mean body weight gain was statistically significantly lower during mating/post mating day 7-14, premating day 1-mating/postmating day 14 and premating day 1 to terminal sacrifice in MD group males when compared with the controls. There was also statistically significantly lower group mean body weight gain observed during premating day 1-7, premating day 1 to mating/postmating day 14, premating day 1 to terminal sacrifice and statistically significantly higher group mean body weight gain during premating day 7-14 and mating/postmating day 7-14 in HD group when compared with the controls.

In females, no statistically significant difference in group mean body weight was observed in treatment groups during entire study period when compared with controls. There was statistically significantly higher group mean body weight gain observed during premating day 7-14 in HD group when compared with the controls.

This statistically and biologically significant effect on body weight and body weight gain in MD and HD group male was considered as test item related and toxicologically relevant. However, statistically significant effect on female group mean body weight gain in HD group was attributed to possible compensatory recovery after the reduction of dose from second week of the study.

Food Consumption:

In males, the food consumption during treatment period tended to increase with the progress of the study in the control, the LD, the MD and the HD group. However, In HD group, during premating day 1-7, food consumption was lower without achieving statistical significance compared to the control group and this effect on food consumption in males was considered to be test item related.

In females, no statistically significant effect on food consumption was observed during premating period, gestation and lactation period in treatment groups when compared with the controls. However, in correlation to body weight development, marginally lower food consumption was observed in HD females during premating day 1-7 when compared with the controls. As this effect on female food consumption was marginal and in the light of no significant effect on body weight development, this effect on food consumption in females was not considered to be adverse.

Thyroid Hormone (T4) Analysis:

No test item related effect of toxicological relevance or statistical significance was observed on male thyroxine hormone (T4) in the treatment groups when compared to the controls.

Haematology and Coagulation:

In males sacrificed at the end of treatment period, no test item related adverse effects were observed for haematological parameters. However, there was a statistically significantly higher platelets (PLT) count observed in HD group compared to the control group. All group mean and most of the individual values were within the historical control data range.

As group mean value was within historical control data limit, statistically significant effect on PLT in HD group was considered to be incidental and not related to the treatment with test item. No test item related effect was observed on coagulation parameters when compared with the controls.

In females sacrificed at the end of treatment period, no statistically significant or test item effect observed on any of the haematology or blood coagulation parameters when compared with the controls. All group mean and most of the individual values were within the historical control data range.

Clinical Biochemistry:

In males and females sacrificed at the end of treatment period, no test item related or statistically significant effect on any clinical biochemistry parameter in treatment groups was observed when compared with the control.

Urinalysis:

The urinalysis performed in selected male and female animals sacrificed at the end of treatment period revealed no test item treatment related effect and all urinary parameters were in the normal range of variation. High protein levels were found in the urine of few male and females of all groups including control group. Therefore, this effect on urine parameters was not considered to be test item related.

Pathology:

Few specific macroscopic changes were recorded for the male and female animals, which based on microscopic examination were not considered to be of test item treatment relevance. However,In decedents, red discoloration observed in the thymus of males no. 35 and No. 38 of HD group was correlated microscopically with congestion and hemorrhage in male no. 35 and with hemorrhage in male no. 38. The above mentioned changes were considered incidental agonal changes which are occasionally found in animals being subjected to necropsy. In survivors, small testes and epididymides recorded in male no. 14 (LD group) correlated microscopically with testis and epididymis atrophy and aspermia. In male No. 21 (MD group) small epididymis on the left side was correlated microscopically with unilateral epididymis atrophy and aspermia. In addition, in the male no. 30, a dilated right kidney was correlated microscopically with pelvic dilatation.In female No. 59 (LD group), the observed diaphragmal herniation corresponded histologically to a hepatic nodule.

The above mentioned changes were considered to be most likely incidental in nature.

Organ Weight:

In males sacrificed at the end of treatment period, there were statistically significantly higher absolute liver weights in all treatment groups (except MD group), higher relative (to body weight) liver weights in MD and HD group and higher kidney weights in LD and HD group although statistical significance only achieved in LD group when compared with the controls. Increased liver absolute weights were histologically correlated with slight hepatocellular hypertrophy only in one animal from the HD group, whereas in the MD and LD group neither the absolute nor the relative increase in liver weight correlated with underlying histological changes. Therefore, without a dose dependent correlation between liver weight increase and the observed histopathological hepatic changes and in absence of hepatic-derived enzyme profiling,the toxicological relevance of the liver weight increase could not be established.

In females sacrificed at the end of treatment period, significantly higher absolute liver weights were observed in HD group when compared with the controls although statistical significance was not achieved.

There were also statistically significantly higher relative (to body weight) kidney weights observed in HD group when compared with the controls.In females, statistically significantly higher relative kidney weights in HD group were considered of no toxicological relevance in absence of correlating histological changes.

Histopathology:

There were a number of early decedents.in females, gastric changes (ulceration in female No. 75 and erosion in female No. 77) contributed to both morbidity and mortality. In males (31, 35 and 38) based on the histopathology investigation, the cause of death was not evident although, there were slight to moderate gastric changes were observed which might have contributed to the morbidity.The above mentioned changes were associated with vacuolization of forestomach epithelial cells (epithelial vacuolization), hyperkeratosis, mixed cell infiltrates and squamous hyperplasia. In male stomach, hyperkeratosis and squamous hyperplasia were observed.In liver minor degree of hepatocytes vacuolation (fatty change) and centrilobular hypertrophy was observed in few males and females. In Survivors of LD, MD and HD groups, test item related histopathology changes were observed in liver, kidney and stomach.

In liver, minor degree of centrilobular hepatocytes hypertrophy was observed only in few males from the HD group and was considered test item related. In kidney,minimal to slight hyaline droplets accumulation in tubular epithelial cells were observed in the majority of males from all dose groups and the control group.This renal change is a male rat specific phenomenon of no toxicological relevance in humans.Minimal to slight tubular basophilia was observed in few animals from the high dose group only. The tubular basophilia was considered most likely related to the test item administration. In stomach, moderate forestomach ulcerationaccompanied by severe multifocal mixed cell infiltrates, moderate submucosal edema wall and epithelial vacuolization was observed in one male from the MD group. Minimal to moderate mixed cell infiltrates mainly located at the limiting ridge and sometimes extending in the adjacent forestomach and glandular stomach submucosa of males and females from the LD and MD groups and only in males from the HD group. Minimal to moderate epithelial vacuolization was noticed in few males from LD, MD and HD dose groups only. Furthermore, a minor degree of hyperkeratosis was observed in some males from the LD and HD dose groups, whereas slight to moderate squamous hyperplasia was present only in few males from the HD group. These changes in stomach were considered to be most likely related to the test item administration.

The test item did not produced any histological evidence of toxicity in the male and female reproductive organs and tissues.

In conclusion, due to the early mortality observed in males and females from the high dose group and the presence of several histopathological adverse changes in different organs, a histomorphological NOAEL (no observed adverse level) could be established at 30 mg/kg bw/day for the male rats and 200 mg/kg bw/day for female rats. (Although the extend of the effects in males at 30 mg/kg is limited to small effects on BW)

Dose Formulation Analysis:

Dose formulation analysis for nominal concentration revealed that nominal concentrations for all formulations were confirmed throughout the study periodas measured concentrations were within acceptance criterion of 10%.

Conclusion

On the basis of this combined repeated dose oral toxicity and reproduction/ developmental toxicity screening test with Naphthalenesulfonic acid, bis(1-methylethyl)-,methyl derivs., sodium salt in male and female Wistar rats with dose levels of 30, 200, and 500/700 mg/kg body weight day the following conclusions can be made:

-   There were few mortalities observed in the study (3 males and 2 females) during the early days of the study at dose level of 700 mg/kg. Histopathologically cause of the death could not be established for all of them. In females, gastric changes (ulceration in female No. 75 and erosion in female No. 77) contributed to both morbidity and mortality.

 -   No adverse effects of test item were found on male and female clinical observations in LD and MD group, clinical signs like slightly to moderately increased piloerection, reduced spontaneous activity and half eyelid closure in HD group could be attributed to treatment with the test item.

-   No adverse effects of test item were found on female body weight development and food consumption in any treatment group. However, test item related effect on male body weight development observed in MD and HD group and on food consumption in HD group.

-   Functional observations, haematology and coagulation, clinical biochemistry, urinalysis, gross pathological findings at necropsy and organ weight remained unaffected in male and females up to dose levels of 500/700 mg/kg bw/day.

-   Histopathologically, in Survivors of LD, MD and HD groups, test item related histopathology changes were observed in liver, kidney and stomach. However, the test item did not produced any histological evidence of toxicity in the male and female reproductive organs and tissues.

The report concluded that, due to the early mortality observed in males and females from the high dose group (at 700 mg/kg bw/day in first week) and the presence of several histopathological adverse changes in different organs, a histomorphological NOAEL could be established at 30 mg/kg bw/day for the male rats and 200 mg/kg bw/day for female rats.

Close examination shows that the only effects observed at MD (200 mg/kg) are a slight lower BW compared to control (-6%) in males, and an increased combined effects in stomach upon histopathological examinations in males and females. (See attached graphs).

All other effects are observed at HD at 700 mg/kg bw (mortality and effects on oestrous cycle) and 500 mg/kg (Bw males, slight effects food consumption, clinical signs, slight effects on liver and kidney weights, and increased platelets in males).

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

30 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

It concerns a combined repeated dose/reproduction screening with dosing of females up to 54 days. The NOAEL of 30 mg/kg is conservative as it is based on limited local effects in the stomach seen at 200 mg/kg bw. Otherwise the systemic NOAEL could be considered to be 200 mg/kg bw/day.

System:

gastrointestinal tract

Organ:

stomach

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Mode of Action Analysis / Human Relevance Framework

Based on its surfactant properties, the structure is not expected to easily pass membrane structures, but cytotoxicity through disruption of cell membrane is expected. This is supported by study results: Available data indicates that the NOAEL is driven by local effects of the substance on skin and gastro-intestinal tract.

Additional information

No data is available on the product Naphthalenesulfonic acid, methyl, butyl, sodium salt (ANS B) (C7-alkyl naphthalene sulfonate) itself. Evaluation is based on read-across to the comparable C7-alkyl naphthalene sulfonate ANS IP. See chapter 13 for support for read-across within the category of Alkyl Naphthalene Sulfonates (ANS).

A Combined 28-day repeated dose toxicity study with the reproduction/developmental toxicity screening test was performed withNaphthalenesulfonic acid, bis(1-methylethyl)-,methyl derivs., sodium salt(C7-alkyl naphthalene sulphonate)in 10 Wistar Han rats/dose/sex by oral gavage.

The test item was administered daily in 4 groups of test animals at dose levels of 0, 30, 200 and 700/500 mg/kg bw/day. The high dose level was reduced from 700 mg/kg bw to 500 mg/kg bw after 6 or 7 days of dose application due to overt toxicity. Females were treated for up to 54 days (until post-natal day 12) and males for 28 days. Dose volumes were adjusted individually based on weekly body weight measurements. The administration volume was 5 mL/kg bodyweight. Dose volumes were adjusted individually based on weekly body weight measurements. Dose levels were based on results from a RF involving evaluation of0, 50, 200, 700 mg/kg in 5 ml/kg in 3 animals/sex/grp, according to the principles of OECD 421 guidance.

 

Results RF: The in-life parameters including body weight and food consumption were not adversely affected in test item groups. One female died on PND 3 after abnormal breathing 2 days before death. A gavaging error cannot be excluded. There were no adverse clinical symptoms observed during the study. There were no pathological findings at necropsy except the found dead female which had fluid filled thoracic cavity and discoloured lung. The organ weights (set of organs) were not affected in males, but in females the ovaries weight was markedly higher in LD (15%), MD (27%) and HD (33%) groups compared to control. The finding was dose response related, but were not statistically significantly different compared to control group. The reproductive indices were not affected. The prenatal, postnatal and litter parameters were not affected due to test item treatment.

Based on the generated data the doses 30, 200 and 700 mg/kg body weight/day could be used for the main study.

 

Results main study:

In the first week, before lowering the HD dosing from 700 to 500 mg/kg bw /day, the HD groups showed overt toxicity.Three males and two females of the HD groups were found dead between day 3 and 6. No further deaths occurred. Clinical symptoms were mainly confined to the HD groups, and specifically in the first week consisted of moderate reduced spontaneous activity, prone position, and eye closed. Further in the study clinical signs included moving the bedding, piloerection and slight reduced spontaneous activity. In the females also the MD animals showed signs of moving the bedding during gestation and lactation. There were no effects on functional observations.

BW of the HD males showed an actual BW loss during the first week (12%), then recovery to MD level. The MD males showed decreased BW gain resulting to 6% lower BW compared to control, but this was not statistically significant. LD dose showed no effects. For the females, there were no significant effects observed on BW. Food consumption was in HD group lower during the first week, and showed a compensatory increase the second week.

During the first 14 days of the study (premating period) estrous cyclicity was evaluated. Most (6/8) females were shown to be completely acyclic, which is considered the result from severe toxicity observed at the start. Upon lowering the dose from 700 to 500 mg/kg bw/day, also recovery of the estrous cycle occurred as is evidenced by pregnancy of all but one of the HD females the week thereafter at mating.

Haematology showed no remarkable findings besides a higher platelet number in HD males which was considered to be incidental. Clinical biochemistry and urinalysis were without findings.

Pathology showed no relevant changes besidesgastric changes (ulceration / erosion) in the two females and slight to moderate gastric changes (hyperkeratosis, squamous hyperplasia, mixed cell infiltrates, epithelial vacuolization) in the three males that died in the first week.

The organ weights show an increased liver weight in the HD males and females which histologically correlated with slight hepatocellular hypertrophy in some animals from the HD group. In absence of effects on hepatic-derived enzyme profiling, the toxicological relevance of the liver weight increase cannot be established. In females there were also statistically significantly higher kidney weights observed in the HD group. These wereconsidered of no toxicological relevance in absence of correlating histological changes.

At histopathology, a minor degree of centrilobular hepatocytes hypertrophy was observed is some animals in the HD group. Also minimal to moderate glycogen accumulation was seen in HD males and females. In kidney, minimal to slight tubular basophilia was observed in few animals from the high dose group only (See attached graph on kidney effects). In stomach,ulceration was observed in one MD male. Other effects as moderate hyperkeratosis, moderate squamous hyperplasia, minimal to moderate epithelial vacuolization, minimal to marked mixed cell infiltrates were observed over all three dose groups. Overall, effects on the stomach show a clear dose related response (See attached graph).The test item did not produce any histological evidence of toxicity in the male and female reproductive organs and tissues.

The report concluded that, due to the early mortality observed in males and females from the high dose group (at 700 mg/kg bw/day in first week) and the presence of several histopathological adverse changes in different organs, a histomorphological NOAEL could be established at 30 mg/kg bw/day for the male rats and 200 mg/kg bw/day for female rats.

Close examination shows that the only effects observed at MD (200 mg/kg) are a slight lower BW compared to control (-6%) in males, and an increased combined effects in stomach upon histopathological examinations in males and females. (See attached graphs).

All other effects are observed at HD at 700 mg/kg bw (mortality and effects on oestrous cycle) and 500 mg/kg (Bw males, slight effects food consumption, clinical signs, slight effects on liver and kidney weights, and increased platelets in males)

As no reproductive effects were observed, the NOAEL for reproduction and developmental toxicity is set at 500 mg/kg bw/day.

 

The fast recovery following initial toxicity to 700 mg/kg bw/day after lowering the high-dose level to 500 mg/kg bw/day suggest a relative low systemic toxicity followed by a steep dose response from that level.

 

Relatively low toxicity is further supported from testing of Sodium (C10-13-)alkylnaphthalene sulfonate: A combined 28-day repeated dose toxicity study with reproduction/developmental toxicity screening, resulted to a parental NOAEL of 300 mg/kg/day and a reproduction and developmental NOAEL of at least 1000 mg/kg/day.

 

 

There are no appropriate repeated dose studies by dermal route available for Sodium (C7-) alkylnaphthalene sulfonate. Available information however suggests that dermal route is not the most sensitive route of exposure for systemic toxicity.

 

Also no information is available from testing of Sodium (C7-)alkylnaphthalene sulfonate via the inhalation route. Exposures by inhalation are not expected in view of the low vapour pressure (1.7 × 10^-4at 25 °C) and experience from its use in the agriculture and mining industry.

The substance is classified for eye irritation. In view of the low systemic toxicity following oral exposures, it can be expected that exposures via inhalation will be characterised by local effects. Testing for acute systemic toxicity via inhalation is therefore not indicated.

Justification for classification or non-classification

The available OECD 422 Combined 28-day repeated dose toxicity study with reproduction/developmental toxicity screening test with Sodium (C7-)alkylnaphthalene sulfonate involved dosing by gavage of dose levels of 0, 30, 200 and 700/500 mg/kgbw/day for 28 days in males and up to 54 days in females. As no significant effects were observed at 200 mg/kg bw/day, and also not expected at 300 mg/kg bw/day, classification for STOT-RE is not required.