Sodium 1,4-bis(1,3-dimethylbutyl) sulphonatosuccinate

Endpoint summary

Description of key information

Subacute toxicity was tested with the registered substance in Wistar rats by oral gavage at 0 (vehicle), 100, 300 and 1000 mg/kg bw/day in a supporting 14-day dose range finding and 100, 300 and 1000 reduced to 600 mg/kg bw/day in a key combined repeated dose/reproductive toxicity study (OECD No. 422). On day 28 of the dosing period the high dose was reduced to 600 mg/kg bw/day due to mortalities and increasing incidence and severity of noisy/laboured respiration. The mortialities and laboured and noisy respiration were related to the very irritant effect of small amounts of test item reaching the upper respiratory tract via reflux or contamination during dosing (as seen during the preliminary study). This is considered as a local effect of the test item. The vehicle was distilled water in the 14-day dose range finding and propylene glycol in the OECD 422 study. The NOAEL for local toxicity of the parental generation was 100 mg/kg bw/day (based on local gastric findings). The NOAEL for systemic toxicity of the parental generation was 300 mg/kg bw/day.

Subacute oral toxicity was also tested similar to OECD 407 method in male rats at 0.125, 0.25 and 0.5% in the diet for 32 days, corresponding with average doses of 130, 250 and 510 mg/kg bw.

Subchronic toxicity testing with registered substance is ongoing and will be updated later when results are available (currently waived in the dossier). Subchronic oral toxicity was further tested equivalent to OECD 408 method in male and female rats at 1% in the diet for 90 days, corresponding with ca. 750 mg act. ingr./kg bw on average basis. These studies did not reveal toxicity, therefore 1% in the diet, corresponding with >= 750 mg act.ingr./kg bw can be accepted as NOAEL. Repeated dose toxicity was tested in various species, including rats, dogs, rabbits and monkeys. The NOAEL of 750 mg/kg bw/day obtained in the key study in rats was confirmed to be consistent with data from docusate sodium and category members in supporting studies in rats; other data from other species were of limited reliability and relevance and therefore not taken into account.

Key value for chemical safety assessment

Toxic effect type:

dose-dependent

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Reference 1

Endpoint:

repeated dose toxicity: oral, other

Remarks:

OECD 422

Type of information:

experimental study

Adequacy of study:

key study

Study period:

18 August 2020 – 22 March 2022 (QA audited draft report)

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2016

Qualifier:

according to guideline

Guideline:

other: OECD No. 43 Guidance Document on Mammalian Reproductive Toxicity Testing and Assessment

Version / remarks:

2008

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Species:

rat

Strain:

Wistar

Remarks:

Crl:WI

Details on species / strain selection:

The test system and the number of animals used in the study were in compliance with the relevant OECD No. 422 guideline. The guideline is designed for use with the rat, which is the preferred rodent species for reproduction toxicity testing. Wistar rat was selected due to experience of the Test Facility with this strain of rat in toxicity and reproduction toxicity studies and its known fertility.
The minimum number of animals was used, corresponding to the regulatory guidelines being followed, but taking into consideration the scientific reliability of the collected information.

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Research Models and Services, Germany GmbH, (Address: Sandhofer Weg 7, D-97633, Sulzfeld, Germany) from SPF colony
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation: Young adult rats, 10/11 weeks old (females/males) at start of the experiment and 12/13 weeks old (females/males) at mating.
- Weight at study initiation: Males: 391-441 g, females: 234-282 g (at the start of the treatment). The body weights did not exceed ± 20% of the mean weight for each sex at start of treatment.
- Housing: Rodents were group-housed, up to 2 animals of the same sex and dose group/cage, with the exception of the mating and gestation, delivery, lactation period, when they were paired or individually housed (with pups), respectively. Animals were housed in animal room 508 in type II, III and/or IV polycarbonate cages. SAFE 3/4-S Hygienic Animal Bedding (Batch number: 03027200428 / 03027200710, Expiry date: 28 April 2023 / 10 July 2023) and SAFE Crinklets Natural nesting material (Batch number: 05072191028 / 05072200405, Expiry date: 28 October 2022 / 05 April 2023) produced by J. Rettenmaier & Söhne GmbH+Co.KG (Address: Holzmühle 1, D-73494 Rosenberg, Germany) were used in the study. Group housing allowed social interaction. Deep wood sawdust bedding allowed digging and other normal rodent activities, while nesting material allowed normal nesting behaviour. Certified cardboard hiding tunnels (GLP Maxi Fun Tunnels, Batch number: 123) produced by LBS (Serving Biotechnology) Ltd. (Address: Unit 20, Gatwick Business Park, Kennel Lane, Hookwood, Surrey, RH6 0AH UK) were also provided to the animals.
- Diet (e.g. ad libitum): The animals received ssniff® SM R/M “Autoclavable complete diet for rats and mice – breeding and maintenance” (Batch number: 560 65984 / 713 70882, Expiry date: 31 October 2020 / 30 April 2021) produced by ssniff Spezialdiäten GmbH (Address: Ferdinand-Gabriel Weg 16, D-59494 Soest, Germany), ad libitum.
- Water (e.g. ad libitum): The animals received tap water from the municipal supply, as for human consumption from a 400- or 500-mL bottle, ad libitum.
- Acclimation period: Environmental acclimation period for the study was 6 days.

DETAILS OF FOOD AND WATER QUALITY:
A sample (approximately 100 g) of batch of diet used in the study was retained and kept under appropriate environmental conditions until the finalization of the study report.
The food was routinely analysed and considered not to contain any contaminants that could reasonably be expected to affect the purpose or integrity of the study.
The quality control analysis of the water was performed once every three months and microbiological assessment was performed monthly, by the local Public Health and Medical Officer Service (H-8200 Veszprém, József Attila u. 36., Hungary). Copies of the relevant Certificates of Analysis were included in the raw data and will be archived at the Test Facility.
The water was considered not to contain any contaminants that could reasonably be expected to affect the purpose or integrity of the study.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20.1-25.0℃ (target range: 19-25°C)
- Humidity (%): 32-68% (target range: 30-70%)
- Air changes (per hr): 15-20 air exchanges/hour
- Photoperiod (hrs dark / hrs light): 12 hours daily, from 6.00 a.m. to 6.00 p.m.

IN-LIFE DATES:
From: start of in-life phase: 19 August 2020 (first vaginal smear sampling)
To: End of in-life phase: 02 November 2020 (last necropsy)

Route of administration:

oral: gavage

Details on route of administration:

The time of the gavage process was prolonged, to be really sure the rat was well relaxed, and the total amount of gavage liquid was administered slowly into the stomach (‘short’ gavage to the lower oesophagus was avoided).

Vehicle:

water

Remarks:

distilled

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS:
As agreed with the Sponsor, total solid content (test item) of the supplied product was taken into consideration during formulation (a conversion factor of 1.255 was applied used for this purpose). Concentrations and all dose levels in the study (including raw data and study report) were expressed as solid matter as requested by the Sponsor.
The test item was formulated in the selected vehicle (distilled water), as a visibly stable homogenous solution at the appropriate concentrations according to the dose levels and volume selected in the Pharmacy of the Test Facility. The formulations were stirred with manual shaking and a magnetic stirrer from the preparation until completion of each treatment.
Formulations were prepared a maximum of 1 or 7 days* prior to administration to animals according to stability assessment results of the analytical method development and method validation studies (Test Facility Study codes: 20/030-316ANE and 20/030-316AN).
*Note: Maximum of 7 days of storage was applied for 20, 60 and 120 mg solid/mL concentration test item formulations, while test item formulation of 200 mg solid/mL concentration was stored for a maximum of 1 day.
Based on those results of the analytical method validation and its extension, the test item formulation in 5-200 mg test item/mL concentration range (equaling 4-159 mg solid/mL range) were stable for at least 7 days when stored at room temperature, while test item formulation at 300 mg test item/mL concentration (equaling 239 mg solid/mL concentration) was proven to be stable for at least 2 days when stored at room temperature.
The appropriate amount test item was weighed into a clean, calibrated glass container and then mixed properly (with manual shaking and/or magnetic stirring) with the needed amount of vehicle to reach homogeneity by visual observation. Formulations were stored in a closed container at room temperature until use.
After filling the syringe with the calculated amount to be given to each individual rat, the outside of the gavage tube was cleaned with a wetted tissue first (using the vehicle of the study) and then with a dry tissue, to reduce any potential surface contamination to an absolute minimum. A constant volume of 5 mL/kg bw was administered to all animals. The actual volume to be administered was calculated and adjusted based on each animal’s most recent body weight.

VEHICLE
- Concentration in vehicle: 0, 20, 60, 120 and 200 mg solid/mL
- Amount of vehicle (if gavage): Dose formulation volume = 5 mL/kg bw
- Lot/batch no. (if required): 202003032 / 202007068

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Sample collection was performed at a total of four occasions (during the first* and last weeks and once approximately midway during the treatment period). Samples were collected immediately after formulation preparation in the Pharmacy of the Test Facility by a responsible member of the Analytical Department.
*Notes: Sampling was made twice on the first week as the High dose was reduced after three days of treatment: As a formulation with different concentration was used for treatment of the High dose animals from Day 4, additional sampling (sampling #2) was made.
On each sampling occasion, top, middle and bottom duplicate samples were taken from the dedicated test item formulations for concentration and homogeneity measurement, one set to analyse (which was collected in replicates as practical) and one set as a back-up, if required for any confirmatory analyses. Similarly, duplicate samples were taken from the middle of the vehicle control formulation for concentration measurement.
After the analytical sampling, the collected formulation samples were stored at room temperature until measurement.
Analysis of control (vehicle) and test item formulations for concentration and/or homogeneity was performed in the Analytical Laboratory of the Test Facility. Representative samples of control (vehicle) and/or test item formulations were analysed at four times during the study (twice during the first week, once midway during the treatment period and once on the last week of treatment).
Any sample not required for analysis was discarded following acceptance of the results of the formulation analysis by the Contributing Scientist #1 (Analyst) and Study Director.
The formulation analysis was conducted within the determined stability period under the control of the responsible Contributing Scientist #1 (Analyst) in compliance with the analytical method validation and the relevant SOPs of the Test Facility.
Analysis of the formulations for concentration and/or homogeneity of test item was performed using a validated analytical HPLC-UV method (High Performance Liquid Chromatography with ultraviolet detection) in the Analytical Department of the Test Facility by using a validated analytical method (Study code: 20/030-316AN). No density measurement was needed for these aqueous formulation as confirmed by the Contributing Scientist #1 (Analyst).
Acceptance criteria of the concentration analysis was 100 ± 10% of the nominal concentration.
Acceptance criteria of the homogeneity was that the CV (coefficient of variation) of replicates (top, middle and bottom of test item formulations) had to be less than 10%.
The measured concentrations of the test item in the different formulations varied between 94% and 102% of the nominal concentrations.
All test item formulations were shown to be homogeneous. The relative standard deviation (RSD) was below 10% in each case.
Formulations were considered to be adequately stable under the study conditions.
Overall, the formulations were considered adequate for the study.

Duration of treatment / exposure:

Dosing of both sexes began after the acclimatisation (6 days) and pre-exposure period (14 days), and it was performed 2 weeks before mating, during the mating, and was continued up to and including the day before the necropsy.
Males were dosed for 28 days (14 days pre-mating and 14 days mating/post-mating period), then were euthanized and subjected to necropsy examination.
Females were dosed for 14 days pre-mating, for up to 14 days mating period, through gestation and up to and including the day before necropsy (13 days post-partum dosing).

Frequency of treatment:

daily on a 7 days/week basis

Dose / conc.:

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

Remarks:

solid

Dose / conc.:

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

Remarks:

solid

Dose / conc.:

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

Remarks:

solid;
The dose level for High dose group was 1000 mg/kg bw/day (using 200 mg/mL formulation) for the first three days (on Days 0-2), then from Day 3 it was reduced to 600 mg/kg bw/day (using 120 mg/mL formulation).

No. of animals per sex per dose:

12 animals/sex/group + 2 males and 6 females for replacement purpose in the high dose group

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale:
The oral route was selected as it is one of the possible routes of human exposure as requested by ECHA based on the information provided by the Sponsor (Decision number: CCH-D-2114489558-27-01/F; Helsinki, 14 November 2019). The way of test item and vehicle control item administration was in compliance with the relevant OECD No. 422 guideline.
The dose levels were selected by the Sponsor in consultation with the Study Director based on the results of a Dose Range Finding (DRF) study (Study code: 20/030-220PE), with the aim of inducing toxic effects but ideally no death or suffering at the highest dose and a NOAEL at the lowest dose.
In the DRF study (after a 14-day treatment period), no mortality occurred in the Control, Low and Mid dose groups (100 and 300 mg solid/kg bw/day, respectively). Two out of the four males and one out of the four females in the High dose group (1000 mg solid/kg bw/day) were found dead during the study; however, the cause of death was considered not to be related to systemic toxicity, rather than local respiratory irritation from reflux or a very small amount of test item (a known issue with strong surfactants). Noisy respiration, laboured respiration, gasping respiration, (increased) salivation, decreased activity, soft faeces, liquid faeces, hunched back, red discharge and piloerection were observed mainly in some of the High dose animals and in one Mid dose animal for a short period. These changes were not ascribed to systemic toxicity, but probably were secondary to respiratory local effects. No test item related effect on body weight, body weight gain or food intake was observed, indicating the local effects of the test item had no major consequences on normal growth.
Overall, 1000 mg solid/kg bw/day, was considered as acceptable for the High dose level of this study, with the implementation of additional cleaning of gavage tubes and refined gavage procedures, to reduce the risk of respiratory contamination with test item. Lower doses were spaced with a factor of approximately 3.
Based on the early observations of this study, the dose level of the High dose group was reduced to 600 mg solid/kg bw/day from the fourth day of the study.
- Rationale for animal assignment (if not random): All adult/parental (P) male and female animals were sorted according to body weight by computer and divided into weight ranges. There were an equal number of animals from each weight group randomly assigned to each dose group to ensure that animals of all test groups were as nearly as practicable of a uniform weight.
This process was controlled by the software PROVANTIS v.9, to verify the homogeneity/variability between/within the groups. Males and females were randomised separately to the dose groups at start of the treatment (Day 0).
- Fasting period before blood sampling for clinical biochemistry: All animals including the randomly selected animals for blood sampling were fasted (overnight period of food deprivation, in case of females this happened after the litter had been culled).

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: General (routine) clinical observations were made once a day*, during the pre-treatment and treatment period in the afternoon (pm).
*Note: No general clinical observations were made on the day of necropsy.
Any clinical sign noted during dosing or at any other occasions (if any) was recorded at the time seen.
Animals were inspected for signs of morbidity and mortality once per day in the pre-treatment period and twice daily in the treatment period (at the beginning and end of each working day). Any animal (including also all premature decedents) which showed clinical signs considered severe was sacrificed to prevent suffering, cannibalism and/or autolysis, and was processed in the same way as the animals subjected to terminal necropsy.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Detailed clinical observations were made at the start of the pre-exposure period and once before the first exposure on Day 0 (to allow for within-subject comparisons), then weekly (in the morning (am), before treatment) and on the day of necropsy.
These observations were made outside the home cage in a standard arena, at similar times as practical. Signs evaluated included changes in skin, fur, eyes, mucous membranes, occurrence of secretions and excretions, and autonomic activity (e.g. lachrymation, piloerection, pupil size and unusual respiratory pattern). Changes in gait, posture and response to handling as well as the presence of clonic or tonic movements, stereotypies (e.g. excessive grooming, repetitive circling), difficult or prolonged parturition or bizarre behaviour (e.g. self- mutilation, walking backwards) were also recorded. Special attention was directed towards the observation of tremors, convulsions, salivation, diarrhoea, lethargy, sleep and coma.
Pertinent behavioural changes and all signs of toxicity including mortality were recorded including onset, degree and duration of signs as applicable.
On Gestation Day (GD) 13 and/or 14 the sperm positive females were examined for the presence of vaginal bleeding or “placental sign” (intrauterine extravasation of blood as an early sign of pregnancy in rat).
Furthermore, mated females were examined carefully around the time of expected delivery for any signs of difficult or prolonged parturition.

BODY WEIGHT: Yes
- Time schedule for examinations: All adult animals were weighed with accuracy of 1 g weekly during the pre-exposure period, then on Day 0, and afterwards weekly, and at termination.
Parent females were weighed on Gestation Day (GD) 0, 3, 7, 10, 14, 17 and 20, on PPD (Post-partum Day) 0, 4, 7, 10 and 13, and at termination. The body weight of the female animals measured on GD3, GD10 and GD17 as well as PPD10 were only additional measurements as aid for the calculation of accurate treatment volumes, but these data was not evaluated statistically.


FOOD CONSUMPTION AND COMPOUND INTAKE (no feeding study):
Animal food consumption was determined by weighing the non-consumed diet with a precision of 1 g at least weekly (on a body weight measurements day). No food consumption was measured during mating. Food consumption was measured more frequently during the lactation period (at least on PPD0, 4, 7, 10 and 13).
Main daily food consumption was calculated for each interval.

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: Blood samples were collected by cardiac puncture under pentobarbital anaesthesia, immediately prior to scheduled necropsy.
- Anaesthetic used for blood collection: Yes: Euthanimal 40% (400 mg/mL sodium pentobarbital solution) was used by intraperitoneal injection
- Animals fasted: Yes: overnight period of food deprivation, in case of females this happened after the litter had been culled
- How many animals: 5 males and 5 females/group randomly selected
- Parameters examined:
RBC: Red Blood Cell (erythrocyte) count
WBC: White Blood Cell (leukocyte) count
Hgb: Haemoglobin concentration
Hct: Haematocrit (relative volume of erythrocytes)
MCV: Mean Corpuscular (erythrocyte)
MCH: Mean Corpuscular (erythrocyte) Haemoglobin
MCHC Mean Corpuscular (erythrocyte) Haemoglobin Concentration
RDW: Red Cell Distribution width
Plt: Platelet (thrombocyte) count
MPV: Mean Platelet Thrombocyte volume
RETIC absolute and %: Reticulocyte count
NE absolute and %: Neutrophil
LY absolute and %: Lymphocyte
MO absolute and %: Monocyte
BA absolute and %: Basophil
EO %: Eosinophil
LUC absolute and %: Large Unstained Cells

Coagulation:
APTT: Activated Partial Thromboplastin Time
PT Prothrombin Time

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: Blood samples were collected by cardiac puncture under pentobarbital anaesthesia, immediately prior to scheduled necropsy.
- Animals fasted: Yes: overnight period of food deprivation, in case of females this happened after the litter had been culled
- How many animals: 5 males and 5 females/group randomly selected
- Parameters examined:
Glucose: Blood sugar concentration
T-BIL: Total Bilirubin concentration
Urea: Urea concentration
Chol.: Cholesterol concentration
Creat.: Creatinine concentration
Phos.: Phosphorus concentration
Na+ : Sodium concentration
K+: Potassium concentration
Ca++: Calcium concentration
Cl-: Chloride concentration
Tot. Prot. : Total Protein concentration
Alb.: Albumin concentration
A/G: Alb/glob ration
AST/GOT: Aspartate Aminotransferase activity
ALT/GPT: Alanine Aminotransferase activity
GGT: Gamma-Glutamyl transferase activity
ALKP: Alkaline Phosphatase activity
BA: Bile acids

SERUM HORMONES: Yes
- Time of blood sample collection:
For thyroid hormone analysis, blood samples were taken by venepuncture (using vena sublingualis in case of adult animals) or decapitation (in case of pups) into tubes containing K3-EDTA as anticoagulant as follows:
from up to two pups per litter on PND4,
from all dams and two pups per litter on PPD14 (females) / PND13 (pups),
from all non-pregnant or not delivered adult females at termination (scheduled / unscheduled),
from all adult males at termination (scheduled / unscheduled).
The collected pup blood (plasma) samples were pooled by litter.
The timing of the blood collection for thyroid hormone determination was as close as possible between animals and at the same time of the day in case of sampling on different days. Timing was documented in the raw data.
Blood samples were kept on ice from sampling until centrifugation (within 30 minutes of collection), then centrifuged rapidly (1600 g / approx. 3000 rpm, 10 minutes, 4°C). The resulting plasma was divided in at least two aliquots (volume target was at least 150 μL for the first aliquot and at least 75 µL for the second aliquot, any remaining sample (if any) was kept as a third aliquot) and stored in an ultra-freezer (-80±10°C) until analysis

URINALYSIS: Yes
- Time schedule for collection of urine: Urine sampling was performed prior to necropsy by placing the selected animals in metabolic cages for approximately 16 hours.
- Metabolism cages used for collection of urine: Yes: for approximately 16 hours
- Animals fasted: Yes: overnight period of food deprivation, in case of females this happened after the litter had been culled
- Parameters examined:
LEU / Leukocyte
NIT / Nitrite
pH
PRO / Protein
GLU / Glucose
UBG / Urobilinogen
BIL / Bilirubin
KET / Ketones
BLD / ERY Blood/Erythrocytes
SG / Specific Gravity
SED / Sediment
VOL / Volume
Colour/Appearance

NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: Assessment of any potential test item related neurotoxicity was performed during the last exposure week (males on Day 23 am, females on PPD13 am). Selected animals were subjected to the functional observation battery, including Irwin test and measurements of the landing foot splay and fore/hind grip strength.
In order to avoid hypothermia of pups, dams were removed from the pups for not more than approximately 30-40 minutes during FOB or 90 minutes during locomotor activity measurement (SMART).
- Dose groups that were examined: Five males and five females/group were randomly selected
- Battery of functions tested: sensory activity / grip strength / motor activity / other:
A modified Irwin test was performed [7] when sensory reactivity to different type of stimuli (e.g. auditory, visual and proprioceptive), assessment of grip strength and motor activity was conducted, and the general physical condition and behaviour of animals was tested. Parameters including body position, locomotor activity, respiration rate, respiration type, piloerection, head searching, compulsive biting or licking, circling, upright walking, retropulsion, jumping, exophthalmos, twitches, clonic convulsions, tonic convulsions, tremor, startle, transfer arousal, spatial locomotion, gait, posture, limb position, finger approach, finger withdrawal, touch escape response, diarrhoea, diuresis, visual placing, grip strength, body tone, corneal reflex, pinna reflex, toe pinch, grasping reflex, positional struggle, skin, mucous membrane colour, salivation, palpebral closure, lachrymation, limb tone, abdominal tone, tail pinch, righting reflex, and/or vocalisation were evaluated.
To measure the landing foot splay, the fore/hind paws of the rat were painted with ink and the rat was dropped from a horizontal position onto the appropriate record sheet covering the examination table. This was repeated 3 times for each animal. The distance between the two resulting ink spots of the hind limbs was measured at the first instance (evaluation of forelimbs was not needed).
Fore/hind grip strength was measured using a grip strength meter (Model GS3, Bioseb, Chaville, France), an instrument designed to quantify objectively rodent muscular strength, in order to identify and assess quantitatively any potential effect of test item. The rats were held appropriately such that the fore limbs were allowed to grip the support bar and gently pulled back until they released the bar; the device measures the maximum grip strength. This was performed 3 times for each animal on each test day. The procedure was repeated with the hind limbs with the appropriate grip support. The results are tabulated with individual and mean data.
Locomotor activity assessment was conducted using Automatic Monitoring System of rat locomotor activity SMART v. 2.5 (Harvard Apparatus, Germany). Locomotor activity was monitored by placing each animal individually into an open-field for 1-hour observation time, when DVD recording of movement was made. Recording was made for a duration of 60 minutes, under dim-light and undisturbed conditions. The DVD was analysed with “SMART” software after all recordings were made to produce the appropriate parameters. Data was evaluated for distance travelled in 5-minute segments. The data from the 5-minute segments was presented graphically with the intention of showing plateau activity in controls and comparing the treatment groups.


IMMUNOLOGY: No

OTHER:
OESTRUS CYCLE MONITORING
Oestrus cycles were monitored by vaginal smears daily during the pre-exposure period before the treatments started. Any females that failed to show a 4-5 days cycles were not included in the study. Vaginal smears were also checked daily from the beginning of the treatment period until evidence of mating (during the pre-mating and mating periods).
Additionally, vaginal smears were prepared and examined for each surviving female on the day of necropsy to determine the stage of oestrus cycle and allow correlation with histopathology of the reproductive organs.

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
Gross necropsy was performed on each adult animal irrespective of the date of death. Terminally (one day after the last treatment), animals were sacrificed under anaesthesia by exsanguination; anaesthetic product was diluted for pups’ euthanasia as required.
After exsanguination the external appearance was examined, cranium, thoracic and abdominal cavities was opened, and the appearance of the tissues and organs were observed macroscopically. Any abnormality was recorded with details of the location, colour, shape and size, as appropriate. Special attention was paid to the organs of the reproductive system.
Vaginal smears were prepared and examined for each female on the day of necropsy to determine the stage of oestrus cycle and allow correlation with histopathology of the reproductive organs.
The number of implantation sites and of corpora lutea was recorded in the females as applicable.
Dead pups and pups killed on PND4 and/or PND13 were carefully examined externally for gross abnormalities. After the external observation, the sex determined at birth was confirmed by observation of the internal reproductive organs, if possible. Presence of nipples/areolae in the PND13 male pups was also recorded.

HISTOPATHOLOGY: Yes
The retained tissues and organs required for histopathology (below) were embedded in paraffin wax; sections were cut at 4-6 µm by microtome and transferred to slides. Tissue sections were stained with haematoxylin-eosin/phloxine and examined by light microscope.
For the adult animals, detailed histological examination was performed as follows:
• on the selected list of retained tissues and organs (as above) in the Control and High dose groups (selected 5 animals/sex/group),
• any animals found dead or euthanized pre-terminally during the study in all groups,
• all macroscopic findings (abnormalities), except of minor order from all animals,
• stomach samples of all animals,
• on the retained reproductive organs (testes, epididymides, prostate gland, seminal vesicles with coagulation gland for males and uterus, cervix, ovary, oviduct and vagina for females) of all animals of the Control and High dose groups.
Special attention was paid to evaluation of the stages of spermatogenesis in the male gonads and histopathology of interstitial testicular cell structure. Detailed histological examination of the ovaries covered the follicular, luteal, and interstitial compartments of the ovary, as well as the epithelial capsule and ovarian stroma.
Special attention was paid to the organ weight, appearance and histopathology of immune-system tissues for any evidence of immunotoxicity (spleen, thymus, lymph nodes, bone marrow).
Special attention was paid to the central and peripheral nervous system tissues for any evidence of neurotoxicity.
No histopathological examination was performed on pups (F1 generation).

Statistics:

See under "Any information on materials and methods incl. tables".

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

The daily administration of Sodium Dihexyl Sulfosuccinate by oral gavage to Wistar rats at a dose level of 100 mg solid/kg bw/day (Low dose group) did not result in test item related clinical signs. In the Mid dose group (300 mg solid/kg bw/day), most animals had minor/transient symptoms of respiratory local effects, related to reflux or by small amounts of test item reaching the upper respiratory tract area in animals; but with no indications of systemic effects of the test item. In the High dose group, the initial dose level of 1000 mg solid/kg bw/day was found to be too high despite very careful gavage procedures to ensure minimal local respiratory effects, so the dose was reduced to 600 mg solid/kg bw/day after three days of treatment.

Mortality:

mortality observed, treatment-related

Description (incidence):

The daily administration of Sodium Dihexyl Sulfosuccinate by oral gavage to Wistar rats at a dose level of 100 mg solid/kg bw/day (Low dose group) did not result in test item related mortality. One Mid dose animal died, related to local effects of the test item. In the High dose group, the initial dose level of 1000 mg solid/kg bw/day was found to be too high despite very careful gavage procedures to ensure minimal local respiratory effects, so the dose was reduced to 600 mg solid/kg bw/day after three days of treatment. A relatively high rate of deaths or euthanasia occurred at the High dose level due to the local effects of the test item; necropsy showed local gastric irritation and respiratory effects.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Test item related adverse effects were observed on body weight parameters in High dose males and females, this was largely transient, in the first week. In High dose females there was a lower weight gain during gestation (~20% less gain than controls).

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Test item related adverse effects were observed on food consumption in High dose males and females, this was largely transient, in the first week.

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):

No test item-related adverse effects were seen in the clinical pathology parameters.

Clinical biochemistry findings:

no effects observed

Description (incidence and severity):

No test item-related adverse effects were seen in the clinical pathology parameters.

Endocrine findings:

no effects observed

Description (incidence and severity):

Under the experimental conditions of this study and based on the results of thyroid hormone measurement, thyroid weights, nipple retention, anogenital distance and external reproductive organs analysis, histopathology and reproductive performance, there was no evidence for any endocrine effects.

Urinalysis findings:

no effects observed

Description (incidence and severity):

No test item-related changes were observed in the urinalysis parameters in male and female animals of any dose groups when compared to control.

Behaviour (functional findings):

no effects observed

Description (incidence and severity):

At the functional observation battery (FOB) and locomotor activity measurement, there were no test-item related changes in animal behaviour, general physical condition, grip strength, motor activity, or in the reactions to different type of stimuli in the control or test groups.

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

In animals with respiratory distress, secondary stress effects were recorded (such as organ weight and histological changes in thymus and adrenals).
There was an increase in the hepatic weight (12-14%) in both sexes of the High dose group, indicating an adaptive hypertrophy, but below the level that is detectable histologically.

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

No adverse test item related systemic macroscopic or microscopic changes were recorded at necropsy or at histopathology evaluation of routine organs/tissues or in any reproductive organs.
Local toxicity was observed as gastric irritation in the High and Mid dose groups (with minimal incidence at the Low dose).
Gastric reflux resulted in irritation, sometimes severe, in the upper respiratory tract, which was lethal in approximately 50% of the High dose and in one animal in the Mid dose animals.

Neuropathological findings:

not examined

Description (incidence and severity):

Treatment-related findings were observed at the High dose level (600 mg solid/kg bw/day). Stomach (non-glandular), thymus and adrenal gland were identified as target organs. It is considered that gastric irritation was a main finding in animals; thymus and adrenal effects were considered as secondary, stress related effects.

Histopathological findings: neoplastic:

no effects observed

Details on results:

-Mortality and morbidity:
One Mid dose female (#3501 on Day 4) and fourteen High dose animals (#4005 on Day 3, #4008 on Day 18, #4009 on Day 2, #4501 on Day 1, #4502 on Day 5, #4503 on Day 1, #4506 on Day 2, #4507 on Day 15, #4509 on Day 4, #4510 on Day 6, #4512 on Day 12, #4601 on Day 32, #4606 on Day 8 and #4609 on Day 39) were found dead during the study. Three High dose animals (#4012 on Day 23, #4505 on Day 17 and #4602 on Day 9) were pre-terminally euthanized. Thus, a total of 1 Mid dose animal (one female) and 17 High dose animals (4 males and 13 females) were lost during the treatment period.
The indication of gavage associated injury was observed in 3/14 High dose rats (#4506, #4509 and #4512).
No clinical signs were observed in case of #4005, #4009 and #4506.
Gasping and/or noisy respiration or red liquid was observed for 5 High dose females prior to death (#4501, #4502, #4503, #4509, #4512). Laboured, noisy or gasping respiration, piloerection, hunched back and distended abdomen was observed prior to pre-terminal euthanasia in case of #4505 (respiratory signs on Days 4-14, hunched back on Days 5-12, distended abdomen on Day 16) and #4602 animals (respiratory sign on Days 3-8, distended abdomen on Days 7-8). Hunched back, piloerection and noisy or gasping respiration was observed in case of #4507, #4510 and #4609 High dose females prior to death. Noisy respiration and piloerection were observed prior to death for #4601 female. Laboured and noisy respiration, piloerection, hunched back and increased salivation was observed for #4606 female prior to death. Noisy respiration was recorded in one found dead male (#4008) from Day 1 to death (Day 18). In one High dose male (#4012) decreased activity, hunched back, laboured and noisy respiration, piloerection and liquid faeces were recorded, this animal was pre-terminally euthanized due to ethical reason on Day 23.
For one Mid dose female (#3501) gasping and noisy respiration was observed prior to death.
-Clinical observations:
The observed clinical signs for found dead or moribund animals are given in the section on mortality/morbidity. The information below applies the surviving animals.
No clinical signs were observed in the Control male and female and Low dose male animals. Noisy or laboured respiration was recorded for two Low dose females (#2511 on Days 1-2, and #2503 on Day 7).
Laboured respiration was observed in 1/12 Mid dose female (#3510) on Day 38 and Day 39. Noisy respiration was observed occasionally in 8/12 Mid dose males and 10/11 Mid dose females from Day 2 to Day 39 and Day 1 to Day 12 , respectively; longer duration was observed only for one female animal (#3510) in the period of Days 14-31 and on Day 39.
Noisy respiration was observed in 6/10 High dose males and 4/5 High dose females from Day 1 to Day 24 and from Day 0 to Day 59, respectively, the longevity of the observation was 5 and 8 days, respectively. Gasping respiration was observed for one High dose female (#4504) on Days 1-2. Piloerection was observed for two High dose females and two High dose males (#4105 on Day 7 and #4109 on Day 2). Laboured respiration was observed for 3/5 High dose females and for 3/10 High dose males on Day 5 and from Day 29 to Day 34 and on Day 2 and from Day 23 to Day 24, respectively. The longest period of the observation was 3 and 2 days, respectively. Mucoid faeces were observed for one High dose male (#4004) on Day 18. Slightly decreased activity was observed for two High dose males (#4109 from Day 2 to Day 3 and #4010 on Day 21, respectively). Hunched back was observed for two High dose males (#4105 on Day 7 and #4109 on Days 2-3,respectively) and one High dose female (#4508 on Days 17-19).
The above findings were probably related to the very irritant effect of small amounts of test item reaching the upper respiratory tract via reflux or contamination during dosing (as seen during the preliminary study). This was considered as a local effect of the test item.
-Body weight and weight changes:
Decreased body weight gain or body weight loss was observed in the High dose groups in the first week of treatment, with females recovering to near control weights by Day 14 and males by Day 28. During gestation High dose females gained about 20% less than controls (p<0.05) but weight gain in lactation was normal in all groups although the total weight gain (Day 0 to termination) remained lower for High dose females (p<0.01).
No test item related adverse effects on body weight or body weight gain were detected in Low or Mid dose (100 and 300 mg solid/kg bw/day, respectively) animals (males or females).
Taking account of the necropsy findings, reduced body weight growth and food intake, particularly in the first week, was considered to be related to gastric irritation and/or reflux with respiratory irritation effects.
-Food consumption and compound intake (no feeding study):
Test item related adverse effects on food consumption were observed in High dose females (600 mg solid/kg bw/day) during the pre-mating and gestation phases, no effect was observed in the High dose males or Mid and Low dose groups (300 and 100 mg solid/kg bw/day, respectively).
In case of High dose females, reduced values compared to control were recorded during the pre-mating period (by 25%) and gestation period (by 13%), statistical significance was reached in both cases (p<0.05). Based on the effect on body weight values, the observed values were considered as a test item related adverse effect.
-Neurological assessment:
There were no changes in animal behaviour, general physical condition or in the reactions to different type of stimuli in the control or test groups.
There was no effect of treatment noted in the Irwin test or during the assessment of grip strength and landing foot splay.
All dose groups of males and females had a normal locomotor activity. In all cases, the initial activity was high, with reduced activity in each 5-minute period to an approximate plateau by about 20-30 minutes. There was no statistical significance between the test item treated animals (males and females) and the Control when evaluating the overall total travelled distance (0-60 minutes), any statistical significance observed occasionally in any 5-minute segment without dose response was considered as incidental. The test item did not increase or decrease the normal locomotor activity, all treated groups had a profile of activity the same as historical control data.
-Haematology:
No test item-related adverse changes were detected in the test item treated animals (males and females) when comparing haematology parameters to the relevant Control data. Occasional statistically significant changes were within the HC range (and with no dose response in some cases), and were considered as biological variability, not related to the test item treatment.
-Clinical Chemistry:
No test item-related adverse changes were detected in the test item treated animals (males and females) when comparing serum chemistry parameters to the relevant Control data.
The statistically significant changes observed in the High dose group (decreased urea and total bilirubin concentration in High dose males, increased urea and decreased chloride concentration in High dose females), had no similar trend in the other sex and were within the historical control range, so were considered as animal variability and not related to the test item treatment.
-Urinalysis:
No test item-related changes were observed in the urinalysis parameters in male and female animals of any dose groups when compared to control.
-Organ weights:
There were no test item treatment-related statistically significant differences among groups of males and females in the weights of organs measured when compared to Controls.
Terminal body weights of test item treated males and females were not significantly different from control animals.
The body-related and brain related weight of the liver was statistically significantly increased (by 13.8% and 14.1%) in the High dose males compared to Control, similarly the body related liver weight was statistically significantly increased in the High dose females (by 12.4%) when compared to Control (Table 13). Based on the males and females both having increased liver weight at the High dose with no histological changes, this fact was considered to be a non-adverse adaptive change.
There were no other statistically significant and biologically relevant differences among groups in the weights of organs measured when compared to Controls.
-Pathology evaluation:
FOUND DEAD ANIMALS / Parental Generation
One Mid dose female (3501) and fourteen High dose animals (4005, 4008, 4009, 4501, 4502, 4503, 4506, 4507, 4509, 4510, 4512, 4601, 4606 and 4609) were found dead.
Macroscopic Findings
….
Microscopic Findings
Test item-related multifocal squamous cell hyperplasia, mixed cell submucosal infiltrate (and single occasion of inflammation) and/or erosion/ulcer of the non-glandular stomach mucosa were seen in 10/14 found dead High dose animals. Erosion/ulcer contributed to death in 5/14 High dose animals. A gavage reflux related to the test item induced findings in stomach appeared as possible contributing factors to death in one Mid dose female and six High dose rats. A gavage reflux-related subacute microscopic changes observed in the lungs included aggregation alveolar macrophages, foreign material (bronchiole), mixed/neutrophilic infiltrates and/or granulomatous inflammation (with foreign material) and mixed/neutrophilic infiltrate in trachea. The indication of gavage associated injury (degeneration/necrosis/inflammation of tunica muscularis in the oesophagus) was observed in 3/14 found dead High dose rats. The stomach lesions in unscheduled deaths were similar in distribution as those seen in animals that survived to the end of the study. At necropsy, these stomach lesions were visualized as discoloration and/or thickness. The severity of erosion/ulcer lesions was higher in found dead animals comparing with terminals.
Decreased cellularity of lymphocytes (cortex) in the thymus and diffuse bilateral cortical hypertrophy of zona fasciculata in adrenals microscopically observed in unscheduled deaths, were considered stress-related findings due to treatment and not a direct toxic effect of the test item. Thymic changes were manifested at necropsy as small thymus.
All other changes were incidental or a common background. The results indicated that gastric and respiratory tract irritation were main factors in the deaths.
…
PRE-TERMINAL EUTHANASIA / Parental Generation
Three High dose animals (#4012, #4505 and #4602) were pre-terminally euthanized.
Macroscopic Findings
Test item-related stomach findings contributing to earlier terminations consisted of squamous cell hyperplasia (and mixed cell submucosal infiltrate) and/or erosion/ulcer of the non-glandular mucosa.
Microscopic Findings
Test item-related stomach findings contributing to earlier terminations consisted of squamous cell hyperplasia (and mixed cell submucosal infiltrate) and/or erosion/ulcer of the non-glandular mucosa. This indicated that gastric irritation was a main factor in the moribund conditions.
…
TERMINAL EUTHANASIA / Parental Generation
Macroscopic Findings
Test item-related macroscopic findings were observed in the stomach (non-glandular) of Mid and High dose animas (dose levels of 300 and 600 mg solid/kg bw/day, respectively) and in the thymus of the High dose group. These changes correlated with microscopic findings.
Diffuse/multifocal thickness of the non-glandular mucosa was observed in 1/23 terminal Mid dose and 13/15 terminal High dose animals. White multifocal discoloration of the non-glandular mucosa was seen in 1/23 Mid dose animal. Small thymus correlated with histopathology was observed in 1/23 High dose animal.
All other changes were incidental or a common background.
Microscopic Findings
Treatment-related findings were observed at the High dose level (600 mg solid/kg bw/day). Stomach (non-glandular), thymus and adrenal gland were identified as target organs. It is considered that gastric irritation was a main finding in animals; thymus and adrenal effects were considered as secondary, stress related effects.
-Thyroid hormone analysis:
Compared to the control, there were no statistically significant thyroid hormone concentration levels recorded in any dose groups of parental males or PND13 pups.
No relevant changes were noted in the absolute or relative (to body / brain) thyroid weights of the parental male or female animals in any dose groups. No histopathology (microscopic) findings were detected in any High dose males or females.
The thyroid gland weights of the PND13 pups were also statistically not different from the Control group.
In summary, there were no effects on the thyroid hormone levels or on the thyroid glands in parental males and females and in the PND13 pups that were ascribed to the test item. 

Key result

Dose descriptor:

NOAEL

Remarks:

local

Effect level:

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

Based on:

other: solid

Sex:

male/female

Basis for effect level:

gross pathology

Key result

Dose descriptor:

NOAEL

Remarks:

systemic

Effect level:

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

Based on:

other: solid

Sex:

male/female

Basis for effect level:

body weight and weight gain

food consumption and compound intake

mortality

Key result

Critical effects observed:

yes

Lowest effective dose / conc.:

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

System:

gastrointestinal tract

Organ:

stomach

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

no

A GLP Validation of the Analytical Method of Sodium Dihexyl Sulfosuccinate, CAS 2373-38-8, EC 219-147-9 (20/030-316AN)

The purpose of this study was to validate a High Performance Liquid Chromatography method with UV detection (HPLC-UV) in order to determine the concentration (of the active ingredient or the total solid content) of AEROSOL® MA-80 E SURFACTANT in formulation, primarily to support OECD No. 422 study (Study code: 20/030‑220P). A secondary purpose was to determine the stability of the test item in the required formulation under its conditions of use and storage.

The procedure was found to be suitable for the analysis. A summary of the method parameters is presented in Table 1.

 

Table 1. Results of the Method Validation (20/030-316AN)

Selectivity	No interfering component was observed
Reinjection repeatability (7 injections)	RSD%≤ 1.9%
Linear range	20 – 1000 µg/mL of the test item (~15.9 – 796.8 µg/mL of total solid content)
Limit of Quantification	20 µg/mL of the test item (~15.9 µg/mL of total solid content) [º0.2 mg/mL (test item inultrapure water)]
Recovery of thetest itemfrom ultrapure water (5 and 200 mg/mL)	104 and 99%
Precision in ultrapure water (5 and 200 mg/mL)	1.6 and 2.1%
Stability of thetest itemin ultrapure water at 5 and 200 mg/mL at room temperature (1 day)	97 and 99%
Stability of thetest itemin ultrapure water at 5 and 200 mg/mL at room temperature (4 days)	99 and 105%
Stability of thetest itemin ultrapure water at 5 and 200 mg/mL at room temperature (7 days)	100 and 104%
Stability of thetest itemin ultrapure water at 5 and 200 mg/mL at 2-8 °C (4 days)	100 and 108%
Stability of the calibration samples in the autosampler at 50 and 500 µg/mL	107 and 100%; At least 37 hours in the autosampler
Stock solution stability	At least 4 days at 5±3 °C

 

Conclusions:

The NOAEL for local toxicity of the parental generation: 100 mg solid/kg bw/day (based on local gastric effects).
The NOAEL for systemic toxicity of the parental generation: 300 mg solid/kg bw/day (Although body weight/food consumed and mortality in the High dose group were ascribed to secondary effects of the test item from the direct local effects; there could theoretically also be a potential systemic effect. Taking a conservative approach 300 mg solid/kg bw/day was applied here).

Executive summary:

The purpose of this OECD No. 422 study was to obtain information on the possible toxic effects of Sodium Dihexyl Sulfosuccinate (CAS 2373-38-8, EC 219-147-9) test item following repeated (daily) administration by oral gavage to Wistar (Crl:WI) rats at 3 dose levels. A control group received the vehicle only (distilled water).

The study also comprised a reproductive/developmental toxicity screening test, intended to provide initial information on possible effects on male and female reproductive performance such as gonadal function, mating behaviour, conception, pregnancy, parturition and also on the development of the F1 offspring from conception to Day 13 post-partum.

The dose levels were selected by the Sponsor in consultation with the Study Director based on the results of a Dose Range Finding (DRF) study. Based on those results, 1000 mg/kg bw/day was selected as the High dose for this study. Based on the results of the first three days of dosing (mortalities in the High dose group), the dose level of the High dose group was reduced to 600 mg/kg bw/day. Concentrations and all dose levels in the study (including raw data and study report) were expressed as solid matter as requested by the Sponsor.

Experimental design:

Group Number	Group designation	Dose level (mg solid/kg bw/day)	Dose formulation concentration (mg solid/mL)	Dose formulation volume (mL/kg bw)	Number of animals
					Male	Female
1	Control	0	0	5	12	12
2	Low dose	100	20		12	12
3	Mid dose	300	60		12	12
4	High dose*	1000 / 600*	200 / 120*		14	18

*Notes: The dose level for High dose group was 1000 mg/kg bw/day (using 200 mg/mL formulation) for the first three days, then it was reduced to 600 mg/kg bw/day (using 120 mg/mL formulation). Replacement animals started on Day 4 or after (#4602, 4609 and 4610) were treated only at 600 mg/kg bw/day. Dose level of the High dose group is shown as 600 mg/kg bw/day in the report text and tables.

Parameters measured during the study included twice a day mortality checking, daily routine and weekly detailed observation of clinical signs, weekly body weight and food consumption measurements and clinical pathology evaluation (including haematology, coagulation, clinical chemistry and urinalysis). Neurological assessment (Functional Observation Battery (FOB) including measurements of the landing foot splay, grip strength as well as locomotor activity measurement) was performed during the last week of the treatment for each sex. In addition, the reproductive performance, pregnancy, parturition and postpartum/lactation period were monitored in the adult animals, and viability, clinical signs and development were evaluated in their F1 offspring until PND13. At termination, necropsy with macroscopic examination was performed. Weights of selected organs were recorded, and representative tissues/organs were sampled and preserved in appropriate fixatives from the adult animals or F1 animals. The thyroxine (T4) levels in the PND13 pups and parental males were also determined.

For the adult animals, a detailed histological examination was performed on the selected list of retained organs of 5 animals/sex in the Control and High dose groups, all found dead or
pre-terminally euthanized animals, and stomach samples of all animals.

Dosing formulation were analysed for concentration and/or homogeneity on four occasions during the study. All test item formulations were shown to be homogeneous. The measured concentrations of the test item in the different formulations varied between 94% and 102% of the nominal concentrations. Overall, the formulations were considered adequate for the study.

RESULTS

In summary, under the conditions of this study the daily administration of Sodium Dihexyl Sulfosuccinate by oral gavage to Wistar rats at a dose level of 100 mg solid/kg bw/day (Low dose group) did not result in test item related mortality or clinical signs. In the Mid dose group
(300 mg solid/kg bw/day), most animals had minor/transient symptoms of respiratory local effects, related to reflux or by small amounts of test item reaching the upper respiratory tract area in animals; but with no indications of systemic effects of the test item. One Mid dose animal died, related to local effects of the test item. In the High dose group, the initial dose level of 1000 mg solid/kg bw/day was found to be too high despite very careful gavage procedures to ensure minimal local respiratory effects, so the dose was reduced to 600 mg solid/kg bw/day after three days of treatment. A relatively high rate of deaths or euthanasia occurred at the High dose level due to the local effects of the test item; necropsy showed local gastric irritation and respiratory effects.

Test item related adverse effects were observed on body weight parameters and food consumption in High dose males and females, this was largely transient, in the first week. In High dose females there was a lower weight gain during gestation (~20% less gain than controls).

At the functional observation battery (FOB) and locomotor activity measurement, there were no test-item related changes in animal behaviour, general physical condition, grip strength, motor activity, or in the reactions to different type of stimuli in the control or test groups.

No test item-related adverse effects were seen in the clinical pathology parameters.

No test item effect on oestrus cycle of parental females was noted.

No test item related changes were noted in the reproductive parameters during mating and gestation, delivery and post-partum/lactation period until PPD14.

There were no adverse effects on the F1 offspring viability, clinical signs, physical or sexual development. No test item related macroscopic finding was recorded for F1 pups at necropsy.

No adverse test item related systemic macroscopic or microscopic changes were recorded at necropsy or at histopathology evaluation of routine organs/tissues or in any reproductive organs. Local toxicity was observed as gastric irritation in the High and Mid dose groups (with minimal incidence at the Low dose). Gastric reflux resulted in irritation, sometimes severe, in the upper respiratory tract, which was lethal in approximately 50% of the High dose and in one animal in the Mid dose animals. In animals with respiratory distress, secondary stress effects were recorded (such as organ weight and histological changes in thymus and adrenals).

There was an increase in the hepatic weight (12-14%) in both sexes of the High dose group, indicating an adaptive hypertrophy, but below the level that is detectable histologically.

Under the experimental conditions of this study and based on the results of thyroid hormone measurement, thyroid weights, nipple retention, anogenital distance and external reproductive organs analysis, histopathology and reproductive performance, there was no evidence for any endocrine effects.

Based on the results of this study, the following No-Observed-Adverse-Effect Levels (NOAELs) were considered:

The NOAEL for local toxicity of the parental generation: 100 mg solid/kg bw/day (based on local gastric effects).

The NOAEL for systemic toxicity of the parental generation: 300 mg solid/kg bw/day (Although body weight/food consumed and mortality in the High dose group were ascribed to secondary effects of the test item from the direct local effects; there could theoretically also be a potential systemic effect. Taking a conservative approach 300 mg solid/kg bw/day was applied here).

The NOAEL for reproductive effects of the parental generation: 600 mg solid/kg bw/day (based on no significant findings).

The NOAEL for pups (F1 generation) development and survival: 600 mg solid/kg bw/day (based on no significant findings).

Reference 2

Endpoint:

sub-chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1969

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The study was conducted according to internationally accepted test guidelines and is considered relevant, adequate and reliable. There were some deviations from the study guidelines, however these did not affect the conclusions and the validity of the study.

Qualifier:

according to guideline

Guideline:

OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity Study in Rodents)

Deviations:

yes

Remarks:

(only one dose per test substance)

GLP compliance:

no

Limit test:

yes

Species:

rat

Strain:

other: Charles River strain albino

Sex:

male/female

Details on test animals or test system and environmental conditions:

- Source: Charles River Breeding Laboratories, North Wilmington, Mass.
- Age at study initiation: Not provided
- Weight at study initiation: 100 g (female rats), 121 g (male rats) on average
- Housing: Individually in standard wire-bottomed steel rat cages
- Diet : Standard rat ration blended with the appropriate amount of test material in a Hobart Mixer
Fresh diets were prepared each week. Each rat was offered an amount of diet sufficient for one week ‘ad libitum’ feeding. However, checks were made periodically to ensure that the food jars were not empty.
- Water: No data provided
- Acclimation period: Not provided

ENVIRONMENTAL CONDITIONS
Not provided

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS: 1.0% in the feed
Taking into account a mean body weight of 250 g and a mean food consumption of 20g/rat/day
(Derelanko M.J., 2008, The Toxicologist's Pocket Handbook, Informa).
1% in the diet = 10000 mg/kg diet corresponds with 10 mg/g diet
20 g feed/rat (250g bw)/day = 80 g feed/kg bw/day = 0.8 g active ingredient/kg bw/day = 800 mg/kg bw/day.
A higher feed intake is possible, e.g. 1000 mg/kg at higher body weight and feed intake, but from a conservative viewpoint 750 mg/kg bw is taken


DIET PREPARATION
- Rate of preparation of diet (frequency):Fresh diets were prepared each week
- Mixing appropriate amounts with (Type of food): standard rat ration

Analytical verification of doses or concentrations:

no

Duration of treatment / exposure:

90 days

Frequency of treatment:

daily

Remarks:

Doses / Concentrations:
1.0%
Basis:
nominal in diet

No. of animals per sex per dose:

For Aerosol MA: 20 male+20 female at 1.0% dietary level + 20 male and 20 female as control

Control animals:

yes, concurrent no treatment

Details on study design:

Experimental Animals
The animals employed in the study were Charles River strain ( Charles River Breeding Laboratories, North Wilmington, Mass.) albino rats. Two hundred and eighty rats (140 males and 140 females) were selected for the experiment, ear-punched with the animal number assigned and housed individually in standard wire-bottomed steel rat cages. Each cage bore a color-coded card identifying the animal with respect to project number, test material assignment, individual animal number and sex.

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes

DETAILED CLINICAL OBSERVATIONS: Yes

BODY WEIGHT: Yes
- Time schedule for examinations: day 0, 15, 30, 45, 60, 75 and 90.

FOOD CONSUMPTION AND COMPOUND INTAKE:
- Food consumption for each animal determined : Yes
and mean daily diet consumption calculated as g food/kg body weight/day: No
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No

FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: No

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: after 84 days
- Anesthetic used for blood collection No data
- Animals fasted: Yes (fasted serum glucose concentration)
- How many animals: 5 rats of each sex (=10) and 10 control
- Parameters checked in table [No.IV and V] were examined.
Hematocrit Value
Erythrocyte Count
Hemoglobin Concentration
Total Leukocyte Count
Differential Leukocyte Count


CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: after 84 days
- Animals fasted: Yes(fasted serum glucose concentration)
- How many animals: 5 rats of each sex (=10) and 10 control
- Parameters checked in table [NoVI and VII] were examined.
Blood Urea Nitrogen (BUN) Concentration
Serum Alkaline Phosphatase (SAP) Activity
Serum Glutamic-Pyruvic Transaminase (SGPT) Activity
Fasted Serum Glucose Concentration


URINALYSIS: Yes
- Time schedule for collection of urine: after 84 days
- Metabolism cages used for collection of urine: No data
- Animals fasted: Yes
- Parameters checked in table [No.VIII] were examined.
Glucose Concentration
Albumin Concentration
Microscopic Elements Examination
pH
Specific Gravity



NEUROBEHAVIOURAL EXAMINATION: Yes , but in general, not specific
- Time schedule for examinations: abnormal reactions and death were recorded daily during the investigation
- Dose groups that were examined: control and 1.0% dose
- Battery of functions tested: sensory activity / grip strength / motor activity / other: No

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes
ORGAN WEIGHTS: Yes

Other examinations:

No

Statistics:

Statistical analyses were conducted upon the absolute organ weights and their corresponding ratios to the weight of the body. An Analysis of Variance was conducted first and any significant effects disclosed by that treatment were further studied by “t” –tests.

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

no effects observed

Behaviour (functional findings):

not examined

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

no effects observed

Details on results:

CAGE SIDE OBSERVATIONS: yes
- Time schedule: daily

DETAILED CLINICAL OBSERVATIONS: no

BODY WEIGHT: Yes
- Time schedule for examinations: biweekly (day 0, 15, 30, 45, 60, 75 and 90).

FOOD CONSUMPTION AND COMPOUND INTAKE: yes
- Food consumption for each animal determined : yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: no

FOOD EFFICIENCY: no

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: yes
- Time schedule for collection of blood: after 84 days
- Anesthetic used for blood collection No data
- Animals fasted:yes (fasted serum glucose concentration)
- How many animals: 5 rats of each sex (=10) and 10 control
- Parameters: Hematocrit, Erythrocyte Count, Hemoglobin Concentration, Total Leukocyte Count, Differential Leukocyte Count

CLINICAL CHEMISTRY: yes
- Time schedule for collection of blood: after 84 days
- Animals fasted: yes
- How many animals: 5 rats of each sex (=10) and 10 control
- Parameters: Blood Urea Nitrogen (BUN), Serum Alkaline Phosphatase (SAP), Serum Glutamic-Pyruvic Transaminase (SGPT), Fasted Serum Glucose Concentration

URINALYSIS: yes
- Time schedule for collection of urine: after 84 days
- Metabolism cages used for collection of urine: No data
- Animals fasted: yes
- Parameters: Glucose Concentration, Albumin Concentration, Microscopic Elements Examination, pH, Specific Gravity

NEUROBEHAVIOURAL EXAMINATION: no

ORGAN WEIGHTS AND ORGAN TO BODY WEIGHT RATIO'S: yes
- organs: liver, kidney

GROSS AND HISTOPATHOLOGY
Following 90 days of feeding, all surviving rats were sacrificed by carbon dioxide asphyxation and autopsied. Animals which died during the study were examined grossly unless examination was precluded by post-mortem autolysis. At the time of gross examination a complete set of organs and other tissues was removed from each rat and preserved in formalin solution. Also at autopsy the weight of the liver and kidneys of ten rats of each sex in every group was determined and recorded.
Microscopic examination of tissues taken from five rats of each sex in every group was conducted. The following tissues, stained with Hematoxylin-Eosin, were included: esophagus, stomach (cardia, fundus and pylorus), small intestine (duodenum, jejunum and ileum), cecum, colon, liver, kidneys, spleen, pancreas, urinary bladder, pituitary gland, adrenal gland, testes, seminal vesicle, ovary, bone marrow, thyroid gland, parathyroid gland, salivary gland, prostate gland, heart, aorta, lung, lymph node (cervical and mesenteric), skeletal muscle, peripheral nerve, bone (femur), spinal cord, uterus, trachea, eye, optic nerve and brain (cerebrum, cerebellum and pons).

Dose descriptor:

NOAEL

Effect level:

1 other: % in the diet

Based on:

act. ingr.

Sex:

male/female

Basis for effect level:

other: No toxicological findings (only a slight significant absolute liver weight decrease in males)

Dose descriptor:

NOAEL

Effect level:

ca. 750 mg/kg bw/day (actual dose received)

Based on:

act. ingr.

Sex:

male/female

Basis for effect level:

other: No toxicological findings (only a slight significant absolute liver weight decrease in males)

Critical effects observed:

not specified

Conclusions:

The comparisons of final body weights and total weight gains revealed no statistically significant differences between test and control animals.
No outstanding differences in food consumption were noted between test rats and control rats.
No deaths or abnormal behavioral reactions were noted among any of the animals employed in the study.
No outstanding differences between test and control rats were noted with respect to any of the blood parameters studied.
No significant differences between the urine of test rats and control rats were observed.
No outstanding differences between test and control rats were noted at the time of gross pathological examination.
There were no significant differences between the tissues of test and control rats observed upon histopathological examination.

Executive summary:

Six groups of 40 albino rats (20 male, 20 female Charles River Strain) plus 1 control group (20 male, 20 female) were fed with 1% of various test items mixed into the diet. The various test items were category members of the Sulfosuccinates Diester Group including Butanedioic acid, sulfo-, 1,4-bis (1,3-dimethylbutyl)ester, sodium salt. After 84 days 5 hematological values, 4 blood chemical values, 5 urinalysis values were measured for all animals. 40 tissues have been examined pathologically at the conclusion of the 90-days test period. Organ to body weight and organ to brain weight ratios were calculated. No significant differences in clinical blood chemistry studies and absolute organ weights have been detected. Body weights organ to body weight ratios, hematologic studies and urinalysis were not different between test and control animals. No deaths or abnormal behavioral reactions occurred; no gross pathological findings were noted.
Administration of category members at 1% in the diet (10000 ppm equivalent to 750 mg/kg body weight/day on average basis) for 90 days in rats did not result in any relevant changes in the subchronic toxicity study. The NOAEL was therefore considered to be ca. 750 mg/kg bw/day.

The IBT Report, supplemented by the Intox report and the Validation Report of October 15, 1983, may be considered a valid study and the data and conclusions relied upon.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

300 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

reliable (Klimisch 1)

Organ:

colon

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

Additional information

Subacute toxicity

A supporting 14-day dose range finding study was conducted with the registered substance in Wistar rats (5/sex/group) by oral gavage at 0 (distilled water), 100, 300 and 1000 mg/kg bw for up to 14 days in order to determine the dose levels for a subsequent OECD No. 422 study (Szalóki, 2021). The measured test item concentration in the dosing formulations varied between 99 to 102% of the nominal concentration. Two out of the four males and one out of the four females in the High Dose group were found dead during the study; however the cause of death was considered not to be related to systemic toxicity, but rather from local respiratory irritation from reflux of a very small amount of test item (a known issue with strong surfactants). Decreased activity, piloerection and liquid faeces were observed in the High dose groups (males and females). Hunched back was observed only in the High dose female group. Gasping respiration and salivation/increased salivation were observed in the High dose female and Mid dose male groups. Noisy and/or laboured respiration was observed in the Mid and High dose males and High dose female group. No test item related effect on body weight, body weight gain or food intake was observed. There was no clearly adverse effect seen in haematology or clinical chemistry. Liver weights were increased in both sexes at the High dose. Other statistical differences in organ weights were relatively slight and were not considered to clearly reflect an adverse effect. Test item-related macroscopic findings in the non-glandular mucosa of the stomach of High dose animals (males and females) and in Mid dose male group at necropsy may reflect a local effect, but in the absence of a significant food intake effect, this was not considered to limit the dose setting for the main study. The 1000 mg/kg bw/day dose level caused some changes but seemed to be acceptable for the High dose level of the OECD No. 422 study.

A key subacute OECD No. 422 study was conducted with the registered substance in Wistar rats (12/sex/group by oral gavage at 0 (propylene glycol), 100, 300 and 1000 mg/kg bw/day (Hargitai, 2022). Based on the results of the DRF study, 1000 mg/kg bw/day was selected as the High dose for this study, however due to the results of the first three days of dosing (mortalities in the High dose group), the dose level of the High dose group was reduced to 600 mg/kg bw/day. Concentrations and all dose levels in the study (including raw data and study report) were expressed as solid matter as requested by the Sponsor. Male and female Wistar rats were treated for 2 weeks pre-mating and then during the mating/post-mating periods. This was 28 days in total for males. Females were treated throughout gestation and up to and including postpartum/lactation day (PPD) 13. Parameters measured during the study included signs of and mortality twice daily, daily general and/or weekly detailed observation of clinical signs, weekly body weight and food consumption, and clinical pathology evaluation (including haematology, coagulation, clinical chemistry and urinalysis). Neurological assessments, including a functional observation battery (FOB) and measurements of the landing foot splay, grip strength and motor activity were performed during the last week of the treatment. Reproductive performance is reported under Section 7.8. At termination, necropsy with macroscopic examination was performed. Weights of selected organs were recorded, and representative tissues/organs were sampled and preserved in appropriate fixatives from the adult animals and/or offspring. The thyroxine (T4) levels in the Day 13 (PPD13) pups and adult males were also assessed. For the adult animals, a detailed histological examination was performed on the selected list of retained organs in the Control and High dose groups.

In summary, the test item at a dose level of 100 mg solid/kg bw/day (Low dose group) did not result in test item related mortality or clinical signs. In the Mid dose group(300 mg solid/kg bw/day), most animals had minor/transient symptoms of respiratory local effects, related to reflux or by small amounts of test item reaching the upper respiratory tract area in animals; but with no indications of systemic effects of the test item. One Mid dose animal died, related to local effects of the test item. In the High dose group, the initial dose level of 1000 mg solid/kg bw/day was found to be too high despite very careful gavage procedures to ensure minimal local respiratory effects, so the dose was reduced to 600 mg solid/kg bw/day after three days of treatment. A relatively high rate of deaths or euthanasia occurred at the High dose level due to the local effects of the test item; necropsy showed local gastric irritation and respiratory effects. Test item related adverse effects were observed on body weight parameters and food consumption in High dose males and females, this was largely transient, in the first week. In High dose females there was a lower weight gain during gestation (~20% less gain than controls). At the functional observation battery (FOB) and locomotor activity measurement, there were no test-item related changes in animal behaviour, general physical condition, grip strength, motor activity, or in the reactions to different type of stimuli in the control or test groups. No test item-related adverse effects were seen in the clinical pathology parameters. No test item effect on oestrus cycle of parental females was noted. No adverse test item related systemic macroscopic or microscopic changes were recorded at necropsy or at histopathology evaluation of routine organs/tissues or in any reproductive organs. Local toxicity was observed as gastric irritation in the High and Mid dose groups (with minimal incidence at the Low dose). Gastric reflux resulted in irritation, sometimes severe, in the upper respiratory tract, which was lethal in approximately 50% of the High dose and in one animal in the Mid dose animals. In animals with respiratory distress, secondary stress effects were recorded (such as organ weight and histological changes in thymus and adrenals). There was an increase in the hepatic weight (12-14%) in both sexes of the High dose group, indicating an adaptive hypertrophy, but below the level that is detectable histologically. Based on the results of this study, the NOAEL for local toxicity of the parental generation was 100 mg solid/kg bw/day (based on local gastric effects). The NOAEL for systemic toxicity of the parental generation was 300 mg solid/kg bw/day (Although body weight/food consumed and mortality in the High dose group were ascribed to secondary effects of the test item from the direct local effects; there could theoretically also be a potential systemic effect. Taking a conservative approach 300 mg solid/kg bw/day was applied here).

Feeding the registered substance (78 -80% purity) in the diet for 32 days at concentrations of 0.125%, 0.25% and 0.5% in the diet of young male albino rats resulted in no significant signs of toxicity (Shaffer, 1957). These concentrations were equivalent to mean daily dosages of about 130, 250 and 510 mg active ingredient/kg bw, respectively. Appearance and behaviour of the animals were normal and at sacrifice and autopsy at the conclusion of the period of feeding, there was no gross pathology that could be attributed to ingestion of the test item. Administration of test item up to 0.5% in the diet (equivalent to 510 mg act.ingr./kg bw/day) for 32 days in rats did not result in any relevant changes in the subacute toxicity study.

 

Subchronic and chronic toxicity

A key 90-day oral repeated dose toxicity study in rats was also available for the registered substance (Plank et al., 1969). Six groups of 40 albino rats (20 male, 20 female Charles River Strain) plus 1 control group (20 male, 20 female) were fed with 1% of various sulfosuccinate category member mixed into the diet. After 84 days hematological values, blood chemical values, urinalysis values were measured for all animals. Tissues were examined pathologically at the conclusion of the 90-days test period. Organ to body weight and organ to brain weight ratios were calculated. No significant differences in clinical blood chemistry studies and absolute organ weights have been detected. Body weights organ to body weight ratios, hematologic studies and urinalysis were not different between test and control animals. No deaths or abnormal behavioral reactions occurred; no gross pathological findings were noted. Administration of category members at 1% in the diet (10000 ppm equivalent to ca.750 mg/kg body weight/day on average basis) for 90 days in rats did not result in any relevant changes in the subchronic toxicity study. The NOAEL was therefore considered worst case to be 750 mg act.ingr./kg bw/day.

The validity of the study was supported by additional audits on the raw data and histopathological evaluation. Although deficiencies were detected compared to current standards, the study was concluded to be valid and reliable.

In a supporting study, groups of 10 (5 male & 5 female) Wistar rats were treated for 6 months at concentrations of 0.25, 0.5, 0.75, 1.0 and 1.25 g/kg diet, corresponding to doses of 190, 370, 550, 750 and 870 mg/kg bw/day. Occasional spells of diarrhea occurred in some animals, particularly at the higher doses. Neither the total red cell, total white cell, nor the differential counts of rats was affected by the continued administration . The dose level of 750 mg/kg was confirmed as NOAEL (Literature, Benaglia et al. 1943).

Other studies were also available from literature in various species (Literature, Benaglia et al. 1943 and Case et al., 1977) in dogs, rabbits and Rhesus monkeys. The other species were considered to be less appropriate due to the gastrointestinal tensioactive local irritation by which systemic effects could not be fully evaluated.

 

Conclusion

- The NOAEL for systemic toxicity of the parental generation was 300 mg/kg bw/day in a key subacute rat combined repeated dose/reproductive toxicity study (OECD No. 422). The oral NOAEL of 750 mg/kg bw/day was obtained in the key dietary subchronic toxicity study in rats with registered substance (OECD 408).

- The fact that no relevant target organ changes were seen up to highest concentration of 1% in diet for 90 days, allows to conclude that corresponding intake of 750 mg/kg bw is NOAEL.

Further information supporting the safety of the test substance is provided in the read across justification for the Diester category, showing that all substances in the group had a NOAEL of at least 750 mg/kg bw (justification with data matrix separately attached in Section 13).

Justification for classification or non-classification

As there were no changes observed below 300 mg/kg bw/day in the subacute study or below 100 mg/kg bw in the subchronic toxicity studies, classification is not warranted according to CLP (No. 1272/2008 of 16 December 2008).