Registration Dossier

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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Description of key information

Key Study:

A subacute (28 -day) repeated dose oral (gavage) toxicity study is available.

This study was designed to assess the systemic toxicity of the test substance to the rat when repeatedly administered orally for a period of 28 consecutive days repeated once daily oral administration.

The test substance was administered by oral gavage, once daily, to three groups of five male and five female rats for twenty-eight consecutive days at dosage levels of 15, 150 or 1000 mg/kg/day. The test substance was used as supplied and administered as a suspension in 1% aqueous methyl cellulose + 0.5% Tween 80 at concentrations of 1.5, 15 and 100 mg/ml . In addition, five male and five female rats were held as a concurrent control receiving the vehicle (1% aqueous methyl cellulose + 0.5% Tween 80) alone at the same dose volume (10 ml/kg/ day) .

Bodyweights, food consumption and clinical observations were recorded during the study for all animals. Sensory reactivity, grip strength and motor activity were assessed in Week 4 of the study. Blood samples for clinical investigations were taken prior to termination and all animals were killed and examined macroscopically on Day 29. At the scheduled necropsy selected organ weights were recorded and a wide range of tissues were preserved. Histopathological examination of specified

tissues was then undertaken.

The following comments in relation to principal findings during the study are made in summary:

There were no unscheduled deaths and no clinical signs indicative of toxicity (including neurotoxicity) throughout the study.

Overall mean bodyweight gains for treated groups were comparable with controls for females at 1000 mg/kg/day.

Food intake for treated groups was generally comparable with controls.

All treated groups generally showed similar efficiencies of food utilisation, in comparison with controls.

Females receiving 1000 mg/kg/day showed statistically significantly lower mean APTT values compared with controls. Mean PT values for these females and mean PT and APTT values for treated males were comparable with controls. There were no other differences from controls which were considered to be possibly attributable to treatment.

There were no differences in organ weights compared with control that were considered to be attributable to treatment.

Macroscopic examination revealed pink contents of all or parts of the gastrointestinal tract in all rats treated with 1000 mg/kg/day, compared with 0/5 male and female control rats. Pink staining on the tail was observed in 1/5 female rats treated with 1000 mg/kg/day, compared with 0/5 female control rats.

An intense red staining material was seen in the large intestine of some animals receiving 1000 mg/kg/day of the compound. No adverse treatment related changes were detected.

In conclusion, 150 mg/kg/day represents the highest NOEL and 1000 mg/kg/day was the NOAEL on this study.

Supporting Study: 14 -Day Repeated Dose Oral (Gavage) Range-Finding Toxicity Study in the Rat

The study was performed to provide information for further repeated dose toxicity studies (OECD 421). The test item was administered to the Wistar Han™:RccHan™:WIST strain rat for a period of fourteen consecutive days at dose levels of 250, 500 and 1000 mg/kg bw/day. A control group was dosed with vehicle alone (Arachis oil BP).

Under the conditions of this study administration of the test substance for fourteen consecutive days at dose levels up to 1000 mg/kg bw/day to Wistar Han™: RccHan™:WIST strain rats did not result in any toxicologically significant findings.

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Referenceopen allclose all

Endpoint:
short-term repeated dose toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Experimental start date 30 January 2002. Experimental completion date: 19 December 2002
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity Study in Rodents)
Deviations:
no
Qualifier:
according to guideline
Guideline:
other: OPPTS 870.3050, Repeated Dose 28-Day Oral Toxicity Study in Rodents, July 2000.
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Limit test:
no
Specific details on test material used for the study:
Identity: ST463
Chemical name: 4- [[5-(anilino)Carbonyl- 2-mehoxyphenyl]azo]-3-
hydroxynaphthttene-2-carboxamde
Appearance: Magenta powder
Storage conditions: Ambient temperature
Lot number: 6558
Expiry: october 2002
Purity: >99.9 %
Samples received: 1st August 2000 and 15 October 2001
Species:
rat
Strain:
other: Crl:CD (SD)IGS BR
Details on species / strain selection:
The abino rat was chosen as the test species as it has been shown to be a suitable model for his type of study and is the species recommended in the test guidelines.The strain Crl :CD(SD)IGS BR of rat used was chosen on he account of the availability of background data.
Sex:
male/female
Details on test animals or test system and environmental conditions:
A total of 46 Crl:CD°(SD)IGS BR rats(23 males and 23 females), 35± 2 days old was received from Charles River (UK) Limited, Manston Road, Margate, Kent, England. selected rats were approximately 6 weeks old when treatment commenced and bodyweight ranges of 183.1 - 208.0 g (males) and 135.4 - 152.1 g (females) were recorded at the start of treatment.

on arrival 40 animals were randomly allocated to the four treatment groups, such that each group contained 5 males and 5 female rats. Each cage was made of stainless steel with stainless steel grid floors. Cages and undercage trays holding absorbent paper were changed at appropriate intervals. At the start of treatment individual bodyweights were within ±20 % of the group mean for each sex.

Animal room temperature and relative humidity were set and generally maintained at 19 - 23°C and 40- 70% respectively during the study. However on occasion a slight deviation outside this range occured resulting in an overall range of 52 - 88% for humidity. These parameters were monitored using a 7 day chart recorder. Air exchange was maintained such that a minimum of 15 air changes per hour occured and lightning was controlled to provide 12 hours continuous artifical light in each 24-hour period.

All rats had free access to tap water via polycarbonate bottles with sipper tubes and to pelleted SDS Rat and Mouse No. 1 modified Maintenance Diet, except as noted under laboratory investigations.

An acclimatisation period of 6 days allowed between arrival/ allocation and the start of treatment.

The remaining spare rats not allocated to study groups were retained during this period then discarded from the study on day 29 without further investigation.

Route of administration:
oral: gavage
Details on route of administration:
The rats were dosed orally as this is a possible route of human exposure to the test substance, which may be ingested accidentally.
Vehicle:
other: 1% aqueous methyl celluloe + 0.5 % Tween 80.
Details on oral exposure:
Preparation of formulations
The test substance,ST463,was administered as a suspension in 1 % aqueous methyl Cellulose + 0.5% Tween 80, A series of suspensions were prepared by direct diludon of the test substance into the vehicle 1 % aqueous mehyl cellulose + 0.5%Tween 80.The test substance was used as supplied and administered in the vehicle(in 1 % aqueous methyl cellulose + 0.5%Tween 80) at concentrations of 1.5,15 and 100 mg/ml.
All suspensions were prepared daily on the day before dosing. Control animals received the vehicle alone at the same dosage volume.

Administration of formulations.
The test substance, ST463,was administered as a suspension in 1 % aqucous mettyl cellulose + 0.5 % Tween 80. Control animals (Group l) received the vehicle alone. The anlmals were dosed at
approximately the same time each day, where possible, using a suitably graduated synnge and a rubber catheter inserted via the mouth into the stomach.The dosage volume administered
to each animal was calculated according to he most recent recorded bodywelght,with individual dose volumes adjusted to the nearest 0.1 ml. A constant dosage volume of 10 ml/kg bodyweight was used.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
FORMULATION SAMPLING AND ANALYSIS
Before commencement of treatment, the suitability of the mixing procedures was determined and specimen formulations at concentrations of 1 and 100 mg/ml were analysed to assess the homogeneity and stability of the test formulation. In addition,samples of formulations prepared for use on Day 1
and Day 9 were analysed to asess achieved concentration.

The concentration of ST463 in the final solution was quantiied by high performance liquid chromatography using ultra-violet detection with reference to dupticate extracted calibration standards prepared at a nominal concentration of 40 μg/ml.

Conclusion:
The mean concentration of ST463 in test formulation analysed during the study were within -19.5 % of the nominal concentrations confirming the accuracy of formulation.

The homogeneity and stability of ST463 in the 1% aqueous methyl cellulose + 0.5% Tween 80 formulations were confirmed at nominal concentration of 1 mg/ml and 100 mg/ml during storage at ambient temperature for 2 days and refrigeration for 2 days. The storage period represented the maximum time from preparation to completion of use.

The analytical procedure was validated for ST463 in aqueous 0.5 % Tween 80 / 1% MC with respect to the specificity of the chromatographic analysis, linearity of detector response, precision of injection, limit of detection, method of accuracy and precision.
Duration of treatment / exposure:
28 days
Frequency of treatment:
Once daily
Dose / conc.:
0 mg/kg bw/day (nominal)
Remarks:
control (group 1)
Dose / conc.:
15 mg/kg bw/day (nominal)
Remarks:
group 2
Dose / conc.:
150 mg/kg bw/day (nominal)
Remarks:
group 3
Dose / conc.:
1 000 mg/kg bw/day (nominal)
Remarks:
group 4
No. of animals per sex per dose:
5 males and 5 females at 0 mg/kg
5 males and 5 females at 15 mg/kg
5 males and 5 females at 150 mg/kg
5 males and 5 females at 1000 mg/kg
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: The high dosage was selected on the basis of a seven day preliminary oral toxicity study. In that study, rats were dosed at levels of 0, 250, 500 or 1000 mg/kg/day. Treatment was well tolerated at 1000 mg/kg/day for seven consecutive days, thus, a dose regimen of 0, 15, 150 and 1000 mg/kg/day was proposed for the main study.
Positive control:
None.
Observations and examinations performed and frequency:
The following observations and measurements were made during the course of the study:

Clinical signs and mortality:
All animals were observed at least once each day from arrival to termination. During the treatment period all anilnals were observed at intervals after dosing each day to monitor any signs of ill health, behavioural changes or reacion to treatment. Rccords of these post dose checks were made daily throughout out the treatment peiod.

A detailed physical examinaion was performed weekly during pre-treatment, weeks 1, 2, 3 and 4 at approximately the same time of day on each occasion. after removal from the home cage, animals were assessed for physical condition and behaviour during handling and after being placed in a standard arena. Any deviations from normal were recorded.

In addition all animals were checked early in each working day and again in the late afternoon to look for dead ormoribund animals.

Neurobehavioural screening:
During Week 4 of treatment, sensory reactivity, grip strength and motor activity assessments were perfomed. Animals were not all tested in one day, but the numbers of animals and the time of testing were balanced across the groups. These procedures were performed prior to any laboratory invesigations and before daily dosing.

Each animal was subjected to the procedures detailed below, on the specified occasions, by an observer who was unaware of the treatment group to which each animal belonged. Before the start of each set of observations, cage labels showing the treatment group were replaced by lables stating only the study, animal and cage number.

Sensory reactivity:
Approach response:
A blunt probe was brought towards the animal’s head until it was close to the animal’s nose (but not touching the vibrissae). The animal’s reaction was recorded as:
1: No reaction or ignores probe
2: Normal awareness and reaction e.g. approaches and/or sniffs probe
3: Abnormally fearful or aggressive reaction

Touch response:
The animal’ s flank was stroked gently with a blunt probe and the reaction recorded as:
1: No reaction or ignores probe
2 : Normal awareness and reaction e.g . turns towards or moves away
3 : Abnormally fearful or aggressive reaction

Auditory startle response
The animal’s response to a sudden loud noise was assessed and scored as:
1 : No response
2: Weak response e.g. ear twitch only
3: Normal response e.g. obvious flinch or startle
4: Exaggerated response e.g. all feet off floor

Tail pinch response:
The animal’s tail was pinched sharply with forceps approximately one third from the tip and the response graded as:
1: No response
2: Weak response e.g. turns around slowly or weak vocalisation without moving away
3: Normal response e.g. jumps forward or turns around sharply, usually with vocalisation
4: Exaggerated response e.g. excessive vocalisation, body movement or aggression

Grip strength:
Forelimb and hindlimb grip strength was measured using strain gauges. Two trials were performed.

Motor activity:
Motor activity was recorded using a Coulboum Infra-Red Activity Monitoring System.
This system uses infra-red detectors to monitor activity. The following categories of activity are recorded: the time spent in locomotor activity, non-locomotor activity and in no movement. The
number of occurrences (events) of each category is also recorded . For reporting purposes, only the time spent in locomotor activity is presented routinely.
For testing, designated animals were placed singly into observation cages. The test session for each animal was 1 hour , with data being collected every 2 minutes.

Bodyweight:
All rats were weighed when allocated to treatment groups on arrival (Day - 6), prior to dosing on Day 0 and on Days 7, 14, 21 and 27 (prior to overnight starvation for clinical pathology). In addition, the bodyweights of all animals were recorded prior to necropsy (Day 28).

Food consumption:
The quantity of food consumed by each cage of rats was measured on a weekly basis (from week 1).
Food intake per rat (g/rat/week ) was calculated using the total amount of food given to and left by each cage in each group and the number of rats in each cage .

Food conversion efficiency:
Food efficiency was calculated over the treatment period Weeks 1 to 4 from bodyweight and food consumption data as the bodyweight gain per unit food consumption expressed as a percentage . The following formula was used:
Food efficiency +(bodyweight gain (g)/ Food consumed (g)) x 100

The food consumed was calculated as indicated in the Food consumption section. The bodyweight gain was calculated from the gain of each animal and used the mean gain in the formula.

Water consumption:
Daily monitoring by visual appraisal was maintained throughout the treatment period. No formal measurements were made.

LABORATORY INVESTIGATIONS
Samples of whole blood were withdrawn from the retro-orbital sinus of all rats under light anaesthesia, using isoflurane, on Day 29. Food was removed overnight from animals prior to blood sampling. The blood samples were collected and divided into tubes as follows:
- 0.5 ml into EDTA anticoagulant for haematological investigations
- 0.5 ml into citrate anticoagulant for coagulation tests
- 0.7 ml into lithium heparin anticoagulant for blood chemistry investigations

Haematology:
The following estimations were performed:
Haematocrit (Hct) L/L
Haemoglobin concentration (Hb) g/dL
Erythrocyte count (RBC ) X 10E12/L
Mean cell haemoglobin (MCH) pg
Mean cell haemoglobin concentration (MCHC) g/dL
Mean cell volume (MCV) fL
Total leucocyte count (WBC) X 10E9/L
Differential leucocyte counts:
Neutrophils (N) X 10E9 /L
Lymphocytes (L) X 10E9 /L
Eosinophils (E) X 10E9 /L
Basophils (B) X 10E9 /L
Monocytes (M) X 10E9 /L
Large unstained cells (LUC)
Cell morphology: The most common morphological changes
(anisocytosis [Aniso-cytosis] , micro/ macrocytosis [Micro-cytosis/Macro-cytosis],
hypo/hyperchromasia [Hypo-chromasia/Hyper-chromasia]), were recorded
as follows:
no abnormalities detected
Platelet count (Pit) X 10E9 /L
The following were performed using the appropriate methodology
as described below:
Prothrombin time (PT) - Method of Quick, A.J.
(The haemorrhagic disease and the physiology of Haemostasis, 1942), using
an ACL 3000 Plus analyser and IL PT-fibrinogen reagent. (sec)
Activated Partial Thromboplastin Time (APTT) - Method of Proctor,
R.R. & Rapaport, S.I (1961), using an ACL 3000 plus analyser and
IL APTT reagent. (sec)

Blood chemistry :
The following parameters were analysed:
Alanine aminotransferase (ALT) U/L
Aspartate aminotransferase (AST) U/L
Urea (Urea) mmol/L
Creatinine (Creat) pmol/L
Glucose (Glue) - Hexokinase mediated assay mmol/L
Cholesterol-Total (Choi) mmol/L
Sodium (Na) mmol/L
Potassium (K) mmol/L
Total protein (Total Prot) g/L
Albumin by chemical assay (Alb) g/L
A/G ratio (Albumin/globulin ratio) Calculated from Total protein and Albumin concentrations
Sacrifice and pathology:
Necropsy:
On completion of the 4-week treatment period (Day 29), all animals were humanely killed by carbon dioxide asphyxiation and subjected to the following detailed necropsy procedure:

All superficial tissues were examined visually and by palpation and the cranial roof removed to allow observation of the brain, pituitary gland and cranial nerves. After ventral mid-line incision and skin reflection, all subcutaneous tissues were examined. The condition of the thoracic viscera was noted, with due attention to the thymus, lymph nodes and heart.

The abdominal viscera were examined before and after removal; the urinary bladder was examined externally and by palpation. The gastrointestinal tract was examined as a whole and
the stomach and caecum were incised and examined. The lungs were removed and all pleural surfaces examined under suitable illumination. The liver was sectioned at intervals of a few
millimetres; the kidneys were incised and examined. Any abnormalities in the appearance and size of the gonads, adrenals, uterus, intra-abdominal lymph nodes and accessory reproductive
organs were recorded.

Organ weight:
The following organs from each animal were dissected free of fat and weighed:
adrenals
brain
epididymides
heart
kidneys
liver
spleen
testes
thymus
Bilateral organs were weighed together.

Preservation of tissues:
Samples of all the tissues, listed on the following page, from all animals were preserved in 10% Neutral Buffered Formalin (except testes/epididymides which were fixed in Bourn’s solution and then
transferred to 70% IMS (Industrial Methylated Spirits)).

In addition, samples of any macroscopically abnormal tissues were routinely preserved, along with samples of adjacent tissue where appropriate.
adrenals
brain (cerebellum, cerebrum and midbrain sections)
caecum
colon
duodenum
epididymides
femur (with joint)
head#
heart
ileum (including peyer’s patches)
jejunum
kidneys
spinal cord (transverse and longitudinal sections at the cervical, thoracic and lumbar levels)
liver (section from all main lobes)
lungs (including bronchi)
lymph nodes (mandibular and mesenteric)
oesophagus#
spleen
sternum#
stomach
testes
thymus
thyroid (with parathyroid)
trachea
urinary bladder
uterus (with cervix)
other macroscopically abnormal tissue
ovaries
pancreas#
prostate
rectum
sciatic nerves (only one examined)
seminal vesicles
# Tissues not examined.
This extensive list of preserved tissues is intended to satisfy any possible future requirements for
further examination of tissues.

Histopathological examination:
Tissues required for microscopic examination in this study are indicated in the previous list. For testes, tissues were embedded in paraffin wax and sections were stained using a standard PAS
(Periodic Acid Schiff ) method. Other tissues were embedded in paraffin wax and sections cut at 4 - 5 micrometres were stained with haematoxylin and eosin .

For bilateral organs, sections of both the left and right organs were examined. Single sections were prepared from each of the remaining tissues required for microscopic examination.

Microscopic examination of prepared slides (from tissues indicated under Preservation of Tissues) was carried out for all main group animals of Groups 1 and 4. Abnormalities were processed and
examined for all animals on the study.
Statistics:
Yes - all statistical analyses were carried out separately for males and females.
Clinical signs:
no effects observed
Description (incidence and severity):
There were no clinical findings observed during the study that were considered to be indicative of toxicity, however in animals dosed at 1000 mg/kg/day red staining of the dorsal body surface was seen in two males, (for one animal sign was seen on Day 6 only, the other male showed the sign from Day 6 to termination). Red staining of the tail was seen in one female (Day 27 to termination).
Mortality:
no mortality observed
Description (incidence):
There were no unscheduled deaths.
Body weight and weight changes:
no effects observed
Description (incidence and severity):
Overall mean bodyweight gains for treated groups was comparable or superior to controls. Thus there was no adverse effect of treatment.
Food consumption and compound intake (if feeding study):
no effects observed
Description (incidence and severity):
There was no effect of treatment on food consumption. Food intake for treated groups was comparable with controls
Food efficiency:
no effects observed
Description (incidence and severity):
All treated groups generally showed similar efficiencies of food utilisation, in comparison with controls.
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
effects observed, treatment-related
Description (incidence and severity):
Females receiving 1000 mg/kg/day showed statistically significantly lower mean APTT values compared with controls. Mean PT values for these females and mean PT and APTT values for treated males were comparable with controls.

There were no other differences from controls which were considered to be possibly attributable to treatment.

Males at 1000 mg/kg/day showed a statistically significant higher mean MCHC value, whilst females at this level showed a lower mean MCHC value, in comparison with controls. However Hb or Hct values for these groups were comparable with controls and the differences from controls were opposite between the sexes. Females at 1000 mg/kg/day also showed a statistically higher mean neutrophil value compared with controls. The high mean value was mainly attributable to a single animal (No.26) which showed a higher individual value than the other animals in the group and hence unduly affected the group mean .
Clinical biochemistry findings:
effects observed, treatment-related
Description (incidence and severity):
Females receiving 1000 mg/kg/day showed a statistically significantly lower potassium value compared with controls. Potassium values for individual treated males were generally comparable with controls.

There were no other differences from controls which were considered to be possibly attributable to treatment.

All treated groups of males showed a statistically significant higher mean sodium values and males receiving 150 or 1000 mg/kg/day showed higher mean albumen values compared with controls. However there was no dosage-relationships and the magnitude of the differences from controls was marginal and similar differences from controls were not noted for treated females.
Urinalysis findings:
not examined
Behaviour (functional findings):
no effects observed
Description (incidence and severity):
An assessment of the detailed physical examination and arena observations carried out during the treatment period did not reveal any clinical signs or changes in behaviour there were considered indicative of neurotoxicity. Motor activity was similar between controls and all treated groups of both sexes.
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
no effects observed
Description (incidence and severity):
There were no differences from controls that were considered to be attributable to treatment.
Gross pathological findings:
no effects observed
Description (incidence and severity):
Pink contents of all or parts of the gastrointestinal tract were seen in all rats treated with 150 or 1000 mg/kg/day, compared with 0/5 male and female control rats. Pink staining on the tail was observed in 5/5 female rats treated with 1000 mg/kg/day compared with 0/5 female control rats.

The incidence and distribution of all other findings were considered to fall within the expected background range of macroscopic findings. These findings were not considered to be of toxicological importance.
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
no effects observed
Description (incidence and severity):
Treatment-related findings:
No adverse treatment related changes were detected.

Other findings:
An intense red staining material was seen in the large intestine of some animals receiving 1000 mg/kg/day. This was considered to be due to the red colour of the test substance and coincided with the gross finding of pink contents from the gastrointestinal tract of animals in this treatment group.

Incidental findings:
Only minor changes were reported which were of a type and severity commonly seen in CD rats of this age at this laboratory and considered to be incidental and of no toxicological importance.
Histopathological findings: neoplastic:
not examined
Key result
Dose descriptor:
NOAEL
Effect level:
1 000 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
clinical biochemistry
haematology
other: In the absence of any clear evidence of toxicity in this study 1000 mg/kg/day can be classed as the No Observed Adverse Effect Level (NOAEL).
Key result
Dose descriptor:
NOEL
Effect level:
150 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: Treatment with ST463 at either 15 mg/kg/day or 150 mg/kg/day for 28 -days was well tolerated and did not result in any treatment related findings.
Critical effects observed:
no
Conclusions:
In conclusion, 150 mg/kg/day represents the highest NOEL and 1000 mg/kg/day was the NOAEL on this study.
Executive summary:

This study was designed to assess the systemic toxicity of ST463 to the rat when repeatedly administered orally for a period of 28 consecutive days repeated once daily oral administration.

ST463 was administered by oral gavage, once daily, to three groups of five male and five female rats for twenty-eight consecutive days at dosage levels of 15, 150 or 1000 mg/kg/day. The test substance was used as supplied and administered as a suspension in 1% aqueous methyl cellulose + 0.5% Tween

80 at concentrations of 1.5, 15 and 100 mg/ml . In addition, five male and five female rats were held as a concurrent control receiving the vehicle (1% aqueous methyl cellulose + 0.5% Tween 80) alone at the same dose volume (10 ml/kg/ day) .

Bodyweights, food consumption and clinical observations were recorded during the study for all animals. Sensory reactivity, grip strength and motor activity were assessed in Week 4 of the study. Blood samples for clinical investigations were taken prior to termination and all animals were killed and examined macroscopically on Day 29. At the scheduled necropsy selected organ weights were recorded and a wide range of tissues were preserved. Histopathological examination of specified

tissues was then undertaken.

The following comments in relation to principal findings during the study are made in summary:

There were no unscheduled deaths and no clinical signs indicative of toxicity (including neurotoxicity) throughout the study.

Overall mean bodyweight gains for treated groups were comparable with controls for females at 1000 mg/kg/day.

Food intake for treated groups was generally comparable with controls.

All treated groups generally showed similar efficiencies of food utilisation, in comparison with controls.

Females receiving 1000 mg/kg/day showed statistically significantly lower mean APTT values compared with controls. Mean PT values for these females and mean PT and APTT values for treated males were comparable with controls. There were no other differences from controls which were considered to be possibly attributable to treatment.

There were no differences in organ weights compared with control that were considered to be attributable to treatment.

Macroscopic examination revealed pink contents of all or parts of the gastrointestinal tract in all rats treated with 1000 mg/kg/day, compared with 0/5 male and female control rats. Pink staining on the tail was observed in 1/5 female rats treated with 1000 mg/kg/day, compared with 0/5 female control rats.

An intense red staining material was seen in the large intestine of some animals receiving 1000 mg/kg/day of the compound. No adverse treatment related changes were detected.

In conclusion, 150 mg/kg/day represents the highest NOEL and 1000 mg/kg/day was the NOAEL on this study.

Endpoint:
short-term repeated dose toxicity: oral
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
Experimental Starting Date: 10 February 2017; Experimental Completion Date: 02 March 2017
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Reason / purpose for cross-reference:
reference to other study
Qualifier:
no guideline followed
Principles of method if other than guideline:
The study was performed to provide information for further repeated dose toxicity studies (OECD 421). The test item was administered to the Wistar Han™:RccHan™:WIST strain rat for a period of fourteen consecutive days at dose levels of 250, 500 and 1000 mg/kg bw/day. A control group was dosed with vehicle alone (Arachis oil BP).

The dose levels were chosen following the conduct of preliminary toxicity investigations performed as part of this study. The results of the study will aid dose level selection for subsequent studies (OECD 421).

GLP compliance:
yes (incl. QA statement)
Limit test:
no
Specific details on test material used for the study:
Identification : ST1031KH (MB002 Pigment#1) P
hysical State/Appearance : Red powder
Purity : 100%
Batch Number : 20160212
Date Received : 03 February 2017
Storage Conditions : Room temperature in the dark
Expiry Date : 01 February 2018
Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals or test system and environmental conditions:
A sufficient number of male and female Wistar Han™:RccHan™:WIST strain rats were obtained from Envigo RMS (UK) Limited, UK. On receipt the animals were examined for signs of ill-health or injury. The animals in the fourteen day study phase were acclimatized for eight days during which time their health status was assessed. A total of twenty-four animals (twelve males and twelve females) were accepted into the fourteen day treatment phase of the study. At the start of treatment the males weighed 311 to 348g, the females weighed 197 to 215g, and were approximately 12 weeks old.

The animals were housed in groups of three by sex in solid floor polypropylene cages with stainless steel mesh lids and softwood flake bedding. The animals were allowed free access to food and water. A pelleted diet was used. Mains drinking water was supplied from polycarbonate bottles attached to the cage. Environmental enrichment was provided in the form of wooden chew blocks and cardboard fun tunnels.


The animals were housed in a single air-conditioned room . The rate of air exchange was at least fifteen air changes per hour and the low intensity fluorescent lighting was controlled to give twelve hours continuous light and twelve hours darkness. Environmental conditions were continuously monitored by a computerized system, and print-outs of hourly temperatures and humidities are included in the study records. The Study Plan target ranges for temperature and relative humidity were 22 ± 3 °C and 50 ± 20% respectively; there were no deviations from these targets.
Route of administration:
oral: gavage
Details on route of administration:
The test item was administered daily by gavage using a stainless steel cannula attached to a disposable plastic syringe.
Vehicle:
arachis oil
Details on oral exposure:
- PREPARATION OF DOSING SOLUTIONS:
For the purpose of this study the test item was prepared at the appropriate concentrations as a solution in Arachis oil BP.

The test item was administered within two hours of it being formulated. It is assumed that the formulation was stable for this duration.

No analysis was conducted to determine the homogeneity, concentration or stability of the test item formulation.
Analytical verification of doses or concentrations:
no
Duration of treatment / exposure:
Fourteen consecutive days
Frequency of treatment:
Daily
Dose / conc.:
0 mg/kg bw/day (nominal)
Remarks:
control
Dose / conc.:
250 mg/kg bw/day (nominal)
Dose / conc.:
500 mg/kg bw/day (nominal)
Dose / conc.:
1 000 mg/kg bw/day (nominal)
No. of animals per sex per dose:
3 per sex per dose
Control animals:
yes, concurrent vehicle
Details on study design:
Before commencing the fourteen day study phase a preliminary investigation was conducted in which one male and one female Wistar Han™:RccHan™:WIST strain rat received three consecutive days of treatment at a dose level of 1000 mg/kg bw/day. The test item was formulated in Arachis oil B.P. and administered at a volume of 4 mL/kg body weight.
Treatment related findings were limited to episodes of red colored faeces and similar discoloration of stomach and intestinal contents (both findings are considered to be associated with the oral administration of a highly colored test item formulation). In addition, a minor terminal weight loss was evident in the treated male. These responses to treatment were considered to be within acceptable limits; therefore no further preliminary investigations were performed.

Animals in the fourteen day study phase were treated as follows:
The test item was administered daily, for fourteen consecutive days, by gavage using a stainless steel cannula attached to a disposable plastic syringe. Control animals were treated in an identical manner with 4 mL/kg of Arachis oil BP.

The volume of test and control item administered to each animal was based on the most recent scheduled body weight and was adjusted on Days 4, 8 and 11.
Positive control:
No.
Observations and examinations performed and frequency:
Clinical Observations:
All animals were examined for overt signs of toxicity, ill health or behavioral change immediately before dosing, up to thirty minutes after dosing and one hour after dosing. Additional observations were also made four hours following dosing (not at weekends or on public holidays). All observations were recorded.

Body Weight:
Individual body weights were recorded on Days 1, 4, 8, 11 and 15.

Food Consumption:
Food consumption was recorded for each cage group for Days 1 to 4, 4 to 8, 8 to 11 and 11 to 15. Food conversion efficiency was calculated retrospectively.

Water Consumption:
Water intake was measured and recorded daily for each cage group.




Sacrifice and pathology:
Necropsy:
On completion of the dosing period, the animals used in preliminary sighting work were killed by intravenous overdose of a suitable barbiturate agent and animals used in the main part of the study were killed by carbon dioxide asphyxiation, followed by exsanguination and subjected to an internal and external macroscopic examination. No tissues were retained.
Clinical signs:
no effects observed
Description (incidence and severity):
Pink staining of body fur associated with the test formulation was observed sporadically in one male treated at 250 mg/kg bw/day, one male and one female treated at 500 mg/kg bw/day and in animals of each sex treated at 1000 mg/kg bw/day during the treatment period.

Staining of body fur is commonly reported when a colored test item has been administered orally and in isolation is therefore considered to be of no toxicological importance.
Mortality:
no mortality observed
Description (incidence):
There were no unscheduled deaths during the study.
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
When compared with controls, fluctuations in periodic body weight gains were evident in animals of either sex, with males from the 1000 or 500 mg/kg bw/day dose groups showing lower mean body weight gains over Days 4 to 11 and 4 to 8, respectively. This resulted in slightly lower overall body weight gains in these males in a dose-related manner. Overall body weight gain in females treated with 500 mg/kg bw/day was also slightly lower than controls but the corresponding values in females from the 1000 mg/kg bw/day dose group was slightly higher than controls. It is worth noting that inter-individual variation was highly particular amongst the males, and these differences may be due to biological variation.
Food consumption and compound intake (if feeding study):
no effects observed
Description (incidence and severity):
There was no treatment-related adverse effect on food consumption or efficiency detected throughout the study.

Males at all dose levels, displayed occasional marginally higher dietary intake than controls, with the corresponding values in the female test groups showing occasional marginal reductions. However, these intergroup differences did not show any dose-dependence, and were therefore considered to be due to normal variation.

Any intergroup differences in food conversion efficiency were considered to be reflective of variations in body weight gain and/or food intake.
Food efficiency:
no effects observed
Water consumption and compound intake (if drinking water study):
effects observed, non-treatment-related
Description (incidence and severity):
Gravimetric measurement of water intake revealed sporadic instances of increased water intake in males from all test item-treated dose groups, with the corresponding females generally showing reductions. The control values in females were atypically high, which may explain the associated intergroup differences, and in the absence of any true dose- relationships, these variations were considered unlikely to be treatment-related.
Gross pathological findings:
no effects observed
Description (incidence and severity):
At terminal necropsy, individual animals of either sex from all test item-treated dose groups showed the presence of pink colored contents along the gastrointestinal tract. In addition, 2/3 males from the 1000 mg/kg bw/day dose group and 1/3 males receiving 500 mg/kg bw/day showed pink discoloration of the glandular and/or non-glandular region in the stomach.

Findings of this nature are commonly observed when a colored test item is administered orally and in the absence of supporting tissue changes these isolated findings are considered to be of no toxicological importance.
Dose descriptor:
NOAEL
Remarks:
14-day
Effect level:
1 000 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: administration of test substance for fourteen consecutive days at dose levels up to 1000 mg/kg bw/day to rats did not result in any toxicologically significant findings.
Critical effects observed:
no
Conclusions:
Under the conditions of this study administration of the test substance for fourteen consecutive days at dose levels up to 1000 mg/kg bw/day to Wistar Han™: RccHan™:WIST strain rats did not result in any toxicologically significant findings.

Dose levels of 0 (Control), 100, 300 and 1000 mg/kg bw/day were chosen for the OECD 421 study.
Executive summary:

Administration of test substance at dose levels of 250, 500 or 1000mg/kg bw/day over fourteen consecutive days of treatment did not result in any convincing evidence of systemic toxicity and on this basis a dose level of 1000 mg/kg bw/day is deemed to be a suitable high dose for use in the subsequent OECD 421 study together with dose levels of 100 and 300 mg/kg bw/day as the low and intermediate dosages, respectively.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEL
1 000 mg/kg bw/day
Study duration:
subacute
Species:
rat
Quality of whole database:
The available toxicity studies conducted on the substance are considered of high reliability and suitable for classification and labelleing, and risk characterisation.

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

No toxicologically significant adverse effects were observed in the available repeated dose toxicity studies; 28 -day repeat dose oral toxicity study, Oral (Gavage) Reproduction/Developmental Toxicity Screening Test in the Rat (OECD 421) and the associated 14 -day range finding study.

Justification for classification or non-classification

Specific target organ toxicity - repeated exposure

Target organ toxicity (repeated exposure) means specific, target organ toxicity arising from a repeated exposure to a substance or mixture. All significant health effects that can impair function, both reversible and irreversible, immediate and/or delayed are included.

A subacute (28 -day) repeated dose oral (gavage) toxicity study has been used to assess the repeated dose toxicity of the substance.

Treatment with the test substance at either 15 mg/kg/day or 150 mg/kg/day for 28 -days was well tolerated and did not result in any treatment related findings. Thus 150 mg/kg/day was classed as the No Observed Effect Level (NOEL) on this study.

Treatment at 1000 mg/kg/day was also well tolerated. However, at this level for females only there were disturbances in APTT and potassium values for which an affect of treatment could not be discounted. As the magnitude of these differences from controls were minimal, the overall clinical condition of the animals was not impaired and there were no corroborative microscopic findings, they were considered not to be of toxicological importance. In the absence of any clear evidence of toxicity in this study 1000 mg/kg/day can be classed as the No Observed Adverse Effect Level (NOAEL).

No significant/adverse toxic effects were therefore observed within the classification guidance value ranges in the CLP regulation for specific target organ toxicity-repeated exposure (Category 2) based on a 28-day exposure.i. e. no significant/adverse toxic effects were seen at or below a dose of 300 mg/kg bw/day.

The affects observed in APTT and potassium values also do not support classification as CLP states for 'effects considered not to support classification for specific target organ toxicity following repeated exposure' the following:

-small changes in clinical biochemistry, haematology or urinalysis parameters and/or transient effects, when such changes or effects are of doubtful or minimal toxicological importance.

Based on these results, the substance is not classified for specific target organ toxicity-repeated exposure.