Registration Dossier

Diss Factsheets

Toxicological information

Repeated dose toxicity: oral

Currently viewing:

Administrative data

Endpoint:
sub-chronic toxicity: oral
Type of information:
other: Read across from analogue substance
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2020

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity Study in Rodents)
GLP compliance:
yes
Limit test:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
4-hydroxybenzenesulphonic acid
EC Number:
202-691-6
EC Name:
4-hydroxybenzenesulphonic acid
Cas Number:
98-67-9
Molecular formula:
C6H6O4S
IUPAC Name:
4-hydroxybenzenesulphonic acid

Test animals

Species:
rat
Strain:
Wistar
Remarks:
CRL
Sex:
male/female
Details on test animals or test system and environmental conditions:
Animal species: laboratory rat
Strain: Wistar CRL (SPF quality – guaranteed, delivered by Charles River via VELAZ )
Supplier: SPF breeding, VELAZ s.r.o., Lysolajské údolí 15/53, 165 00 Prague 6, Czech Republic, RČH CZ 11760500
Sex: males and females
Age of animals: males, females – sexually adult (8 weeks on arrival, females nulliparous and non-pregnant)
Selection of animal species: laboratory rat has been chosen because our testing laboratory has long experience with this species
Acclimatization: 5 days
Number of animals: 10 females and 10 males per group, 6 males and 6 females per satellite group

Animal housing: SPF (Specified Pathogen Free) animal house of CETA in SPF conditions according to internal SOP No. 12. Animals were housed in the animal room, 2 rats of the same sex in one plastic cage (polycarbonate cages for rats TECNIPLAST, type 1291H, Italy).

Bedding : Sterilized shavings or Lignocel (Raw material: spruce; Producer: J. Rettenmaier & Söhne, Germany).

Housing conditions
approximately 15 air changes per hour
Temperature: 22+3 °C
Relative humidity: 30-70 %
12-hour light/12-hour dark cycle

Identification
Identification of animals was made using colour marks (colour for veterinary usage) on their fur (system 1 – 10 of main groups, 1 - 6 of survival group), each cage was marked with the number of study, number of animals, sex, number of cage, name and dose of the test item and mark of group (according to internal SOP No. 26) .

Feeding: Free access to food (ad libitum).

Diet: Complete pelleted diet for rats – Altromin 1321
Manufacturer: Altromin Spezialfutter GmbH & Co. KG, Germany

Water
Free access to drinking water (water ad libitum). Water quality corresponded to Regulation No. 252/2004 Czech Coll. of Law, Ministry of Health.

Additional information
The standard pelleted laboratory animal diet is analysed for nutrients (once a year) and bacteriological contaminants every 2 months on a regular basis. Results are retained in the CETA archives. Certificates of drinking water analysis (performed twice a year) are retained in the CETA archives. Analysis of diet and water did not reveal any findings that could affect study integrity.

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
other: aqua pro-injectione
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
The stability and the homogeneity of application form were determined in CETA analytical laboratories (Analytical Group I). Jana Volková, Dipl. Eng. was established as Principal Analytical Chemist for this work. The results of analyses are stated in Annex 1 to this report.

Analytical method
The analyses were performed by HPLC method developed at our test facility. Analytical method was designed for determination of homogeneity and stability of test item 4-hydroxybenzenesulphonic acid.

Preparation of application forms
According to the Sponsor´s requirement the dose levels of the test item were recalculated to 100% of 4-hydroxybenzenesulphonic acid (active ingredient).
The concentration level 10mg/10mL mentioned further contains 10 mg of active ingredient per 10 ml volume and the concentration 1000 mg/10 mL contains 1000 mg of active ingredient per 10 ml volume.

Analysis
The first sampling (time interval 0 min) for the measuring of homogeneity and stability was carried out after 30 minutes of mixing by the magnetic stirrer (500 rpm) for both conc. level (10 mg /10 mL and 1000 mg /10 mL).

Homogeneity
The samples were taken after 30 minutes of mixing by magnetic stirrer (500 rpm) from 3 given places - the bottom, the middle and the surface of the beaker content for the determination of homogeneity of both application forms. Two samples were taken from each place.

Stability
The samples were taken from the middle of the beaker content at required time intervals (0, 30, 60, 90 and 120 minutes) for the determination of stability of both application forms. Two samples were taken at all time intervals.
Time interval 0 min represents for both concentration levels the time after 30 minutes of mixing by magnetic stirrer at 500 rpm.

Results of analysis
It follows from the results of analyses (homogeneity and stability) that the both application forms of the test item, 4 hydroxybenzenesulphonic acid (HBSA), (10 mg and 1000 mg /10 mL), at defined laboratory conditions (laboratory temperature, preparation of solution by defined manner) are homogenous and stable at least for 120 minutes from the finalization of application form preparation.
Duration of treatment / exposure:
90 days
Frequency of treatment:
The animals were treated daily at the same time (8.00 – 10.00 am).
Doses / concentrationsopen allclose all
Dose / conc.:
0 mg/kg bw/day (nominal)
Dose / conc.:
250 mg/kg bw/day (nominal)
Remarks:
Based on active ingredient
Dose / conc.:
500 mg/kg bw/day (nominal)
Remarks:
Based on active ingredient
Dose / conc.:
1 000 mg/kg bw/day (nominal)
Remarks:
Based on active ingredient
No. of animals per sex per dose:
10 females and 10 males
Control animals:
yes, concurrent vehicle
Details on study design:
Stability and homogeneity determination
Before the start of animal experiments, the stability and homogeneity of application forms were determined at the test facility.

Dose Range Finding
For the determination of dose levels for main study the Dose-Range Finding Experiment was performed as it is described in Annex 2 of this final report.
The dose-range finding experiment with 28-day application period was performed with 3 groups of treated animals and 1 group of control animals. Dose levels 0, 250, 500 and 1000 mg of a.i./kg/day were used.
No animal died during the application period. Clinical observation did not detect the impact of the test item on the health condition of animals at all dose levels. Slight changes of body weight were adequate typical to species, sex and age of animals in experiment. The administration of the test item did not induce treatment-related toxicologically significant changes of red and white blood components in both sexes. No macroscopical changes related with the test item toxicity were observed during necropsy. On the basis of the results of the dose range finding experiment, the following dose levels – 0, 250, 500 and 1000 mg of a.i./kg/day were proposed for the main Repeated Dose 90-day Oral Toxicity Study.

Main study
In the main study the test item was orally administered (by gavage) daily in graduated doses of active ingredient to several groups of experimental animals, one dose per group for a period of at least 90 days during the period of administration, the animals were observed closely for signs of toxicity of the test item. At the end of administration period the blood collection for haematological and biochemical examination was performed. Animals were humanely killed and necropsied. Sperm analysis (motility and morphology) was performed. The organs for biometry of organs organ weights were recorded and histopatological examination were collected. The NOAEL (No Observed Adverse Effect Level) for toxicity in males and females was determined.




Examinations

Observations and examinations performed and frequency:
Body weight: weekly
Food consumption: weekly
Water consumption: 3 times a week
Mortality observations: twice daily
Health condition control: daily
Clinical observations: daily
Behavioral assessments: weekly
Functional observation: at the last week of administration (13th week) and recovery period (17th week)
Ophthalmological examination: at the 1st week of study and at the last week of administration and recovery period
Urinalysis: 90th day of study (main groups), 118th day of study (satellite groups)
Haematological examination: 91st day of study (main groups), 119th day of study (satellite groups)
Clinical biochemistry: 91st day of study (main groups), 119th day of study (satellite groups)


Sacrifice and pathology:
Biometry of organs: 91st day of study (main groups), 119th day of study (satellite groups)
Pathological examination: 91st day of study (main groups), 119th day of study (satellite groups)
Other examinations:
Sperm analysis: 91st day of study (main groups), 119th day of study (satellite groups)
Statistics:
See details in "Any other information on materials and methods incl. tables"

Results and discussion

Results of examinations

Clinical signs:
no effects observed
Mortality:
mortality observed, non-treatment-related
Description (incidence):
Two deaths of males were recorded during the study. Both deaths are considered as accidental, not related to test item administration.
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
The test item treatment caused reduced body weight in treated males. This body weight reduction was dose dependent from the 9th week of application of the test item and statistically significant in males at the dose level 1000 mg of a.i./kg/day. The body weight of males from the dose level 1000 mg/kg bw/day a.i. at necropsy was reduced by 11.2% in comparison with the control males. Bodyweight reduction in males was considered related to the test item treatment.
The body weight loss was not recorded in any treated group of females. In females of the highest dose level (1000 mg of a.i./kg/day) the body weight was slightly (statistically non-significantly) higher in comparison with the control females.


Food consumption and compound intake (if feeding study):
no effects observed
Food efficiency:
effects observed, treatment-related
Description (incidence and severity):
The food conversion in males at the dose level 1000 mg of a.i./kg/day was decreased in comparison with the control males (corresponds with the reduced body weight of treated males). In treated females, no significant difference in food conversion was recorded.
Water consumption and compound intake (if drinking water study):
effects observed, treatment-related
Description (incidence and severity):
The water consumption of treated males was higher compared to the control group during almost whole application period. The highest water consumption was recorded in males at the dose level 1000 mg of a.i./kg/day. Because the water consumption in satellite treated males during the recovery period was similar with the satellite control males, the increasing of water consumption during the main study can be related to the test item treatment. No significant differences in water consumption was recorded in treated females.
Ophthalmological findings:
no effects observed
Haematological findings:
effects observed, treatment-related
Description (incidence and severity):
Haematological examination showed statistically significant differences in parameters at all dose levels in comparison with the control group of animals.
All haematological values were in a historical control range. Changes in haematological parameters could be considered as the response of organism to the test item administration. These changes were not observed during the recovery period (except increasing value of WBC in females which persisted in satellite treated females). Because the test item had negative effect on stomach mucosa – stomach lesions including erosion (confirmed by histopathological examination), haematological changes can be related to the test item administration.


Clinical biochemistry findings:
effects observed, treatment-related
Description (incidence and severity):
Biochemical examination showed statistically significantly changed parameters in all dose levels of males. Statistically significantly increased values of calcium (Ca), phosphorus (IP) and bile acid (BA) were recorded in all dosed groups. The value of HDL cholesterol was statistically significantly increased in males at the dose levels 500 and 1000 mg of a.i./kg/day. All changes were reversible – not recorded in satellite treated group of males at the end of recovery period.
An irreversible change in concentration of natrium ions was observed. The value of Na+ was significantly increased in males at the dose level 1000 mg of a.i./kg/day and was recorded also in satellite treated group of males at the end of recovery period. This change can be related to the test item administration.
Statistically significantly increased values of triglycerides (TG), phosphorus (IP) and decreased value of cholinesterase (CHE) were recorded in females at the dose levels 500 and 1000 mg of a.i./kg/day. Statistically significantly increased value of calcium ions (Ca) and HDL cholesterol were recorded in females at the dose level 500 mg of a.i./kg/day. The value of creatinine (Crea) was significantly decreased in females at the doses 250 and 500 mg of a.i./kg/day. All changes were reversible – not recorded in satellite treated group of females at the end of recovery period.
Statistically significantly decreased value of alanine aminotransferase (ALT), glucose (GLU) and chloride ions (Cl) were recorded in satellite treated groups of females. These changes in biochemical parameters were not accompanied by histological changes in the liver.
Altered parameters in males ALT (1.20 and 1.29 µkat/L at the dose level 500 and 1000 mg of a.i./kg/day) were slightly above the upper limit of historical control (0.44 – 1.07 (µkat/L) and also the value of HDL (0.66 mmol/L) in males at the dose level 500 mg/kg bw/day a.i. was slightly above the upper limit of historical control (0.40 – 0.64 mmol/L). This can be related to the test item as a response of organism to the test item administration.
Other biochemical values were in a historical control range
Melas: Statistically significant differences in concentrations of T4 and TSH hormone were not detected.
Concentration of T3 hormone was significantly increased in males at the dose levels 500 and 1000 mg/kg/day.
Because no histopathological findings related to the test item administration were reported within the histological evaluation of thyroid gland, these changed values are considered to be an incidental finding.
Females: Statistically significant differences in concentrations of T3 and TSH hormone were not detected.
Concentration of T4 hormone was statistically significantly decreased in females at the dose level 500 mg/kg/day.
Because no histopathological findings related to the test item administration were reported within the histological evaluation of thyroid gland, these changed values are considered to be an incidental finding.
Urinalysis findings:
effects observed, treatment-related
Description (incidence and severity):
The urine examination showed significant differences in pH value related to the test item treatment. The pH value of urine was decreased dose-dependently in dosed males. Statistically significantly decreased pH of urine was detected in males at all dose levels in comparison with the control group of males. In satellite treated males the pH of urine was similar with the control group of males at the end of recovery period. Statistically significantly decreased urine volume in males at the dose level 1000 mg of a.i./kg/day was noted. The decrease (statistically significant) of urine volume was also reported in satellite treated males at the end of recovery period.
Statistically significantly decreased pH of urine was detected also in females at the dose level 1000 mg/kg bw/day a.i. The decrease of pH was observed at all dose levels in dose dependency. Statistically significantly increased volume of urine was detected in females at the dose level 250 mg/kg bw/day a.i. No statistically significant changes in volume and pH of urine were detected in satellite treated females at the end of recovery period.
Behaviour (functional findings):
no effects observed
Organ weight findings including organ / body weight ratios:
effects observed, non-treatment-related
Description (incidence and severity):
Organ Weights showed statistically significantly altered organ weights in treated animals only sporadically. All changes were reversible. Histological examination revealed no histopathological findings related to organ weight change.
In males, increased absolute weights of adrenal glands was recorded only in the dose level 1000 mg of a.i./kg/day. Statistically significantly changed relative weight of organs in treated males was observed only in males at the dose level 1000 mg of a.i./kg/day. Increased relative weight of adrenal glands, testes and brain was recorded.
In satellite treated males, the absolute and relative weight of testes was increased.
In females, dose-dependent increase of absolute and relative weight of liver was observed. Statistically significantly changed weight of liver was recorded in females at the dose levels 500 and 1000 mg of a.i./kg/day.
In satellite treated females, relative weight of uterus was statistically significantly decreased. It is due to the non-pathological findings in females – dilatation of uterus, which is not related to the test item administration.
The evaluation of organ weights did not show any test item related differences. All changed values were not of biological or toxicological significance.
No histopathological findings that correlated with organ weight changes were recorded, therefore all changes were considered not of to be biologically or toxicologically significant.

Gross pathological findings:
effects observed, treatment-related
Description (incidence and severity):
Macroscopic findings on stomach mucosa related to the test item administration (multiple foci of red colour) were recorded. This was confirmed by histopathological examination, where the findings would indicate a toxic effect of the test item on a stomach of dosed animals. Macroscopic findings were reported only in animals of the highest dose level (1000 mg of a.i./kg/day). Multiple foci of red color on stomach mucosa were recorded in 3 of 9 males and swollen congested mucosa of stomach was recorded in 2 of 10 females.
No macroscopic findings related to the test item administration were recorded at the end of recovery period in satellite treated males and females.
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Description (incidence and severity):
Histological examination revealed toxic effect on stomach mucosa in dosed males and females. Oral administration by gavage of the test item in the highest dose (1000 mg of a.i./kg/day) caused stomach erosion in one case and distinctly increased incidence of the stomach lesions (focal acute or chronic inflammation in the submucosa, focal submucosal edema, intestinal metaplasia, presence of hemosiderin). Subsequent examination of the stomach of rats from the middle dose group (500 mg of a.i./kg/day) found small erosions in two males and focal intestinal metaplasia in one female. Focal acute inflammation in the submucosa was found in three males and six females. Submucosal edema was observed in one female. Low dose group (250 mg of a.i./kg/day) rats showed incidence of focal acute inflammation of 9 males and oedema in the stomach submucosa similar to the control animals. Distinctly increased incidence of the described stomach lesions including erosions was considered related to test item administration. Withdrawal of the test item in satellite animals for 28 days led to decrease of the incidence of focal acute inflammation and oedema to the control level. No erosion or intestinal metaplasia were found in recovered (satellite) rats. The described lesions accompanied by minimal to mild focal hyperplasia of the forestomach mucosa were revealed in the most of high dose rats (8 of 9 males and 8 of 10 females), ten animals from the middle dose group, and three rats from the low dose group. This finding was dose-dependent and recorded in 0-2-4-8 males and in 0-1-6-8 females (dose group 0-250-500-1000 mg of a.i./kg/day). At the end of recovery period was this finding in minimal extent revealed in 0-2 males and 0-3 females (satellite dose group 0S-1000S mg/kg bw/day a.i.).
Histopathological findings: neoplastic:
no effects observed
Other effects:
no effects observed
Description (incidence and severity):
Sperm analysis did not show negative effect of the test item treatment on males. A comparison of sperm motility in the control males and males from treated groups did not show differences. The test item treatment did not affect sperm morphology. Histological evaluation of testes and epididymides did not reveal findings related to the test item administration.

Effect levels

Dose descriptor:
LOAEL
Effect level:
ca. 250 mg/kg bw/day (nominal)
Based on:
act. ingr.
Sex:
male/female
Basis for effect level:
clinical signs
gross pathology
haematology
histopathology: non-neoplastic
mortality
organ weights and organ / body weight ratios
urinalysis

Target system / organ toxicity

Critical effects observed:
yes
Lowest effective dose / conc.:
250 spores/kg bw/day (actual dose received)
System:
gastrointestinal tract
Organ:
stomach
Treatment related:
yes
Dose response relationship:
yes

Any other information on results incl. tables

Guideline OECD 408
Substance HBSA
Tested dose 0, 250, 500 and 1000 mg a.i./kg/day
Species  Wistar rats - SPF
Number of animals per dose 10 males and 10 females
Type of administration oral gavage
Mortality No mortality related to test item treatment
health condition and clinical observation No serious changes of animal health status and clinical symptoms of intoxication were observed in treated animals.
Functional observation The functional observation did not show differences between the treated groups and control group of animals.
Body weight  Males: Statistically significant differences were found in groups of males at the dose level 1000 mg /kg/day in comparison with the control group of males. 
Females: The body weights and body weight at necropsy were similar in females of treated groups compared to control for the whole application period.
Food consuption Food consumption was comparable to the control group during the whole application period for males and females
Water consuption Males and females: The water consumption of treated males was higher compared to the control group during almost whole application period. 
Ophthalmological examination The ophthalmologic examination did not show differences between the treated groups and control group of animals.
Haematological examination - males Statistically significantly decreased value of total leucocyte count was recorded in males at the dose level 250 mg of a.i./kg/day. Sporadic differences were recorded in differential count of leucocytes across all doses.
Decreased value of lymphocytes was recorded at the dose levels 250 and 1000 mg of a.i./kg/day.
Increased value of monocytes at the dose level 500 mg of a.i./kg/day.
Increased value of neutrophils in males at the dose level 1000 mg of a.i./kg/day.
Increased value of RBC (total erythrocyte count) associated with the decreased MCV (mean corpuscular volume) were recorded in all dosed group of males.
Decreased value of Hgb (hemoglobin) was recorded in males at the dose levels 500 and 1000 mg of a.i./kg/day.
Statistically significant increased Plt (platelet count) was recorded in males at the dose level 500 and 1000 mg/kg/day. Statistically significantly prolonged PT (prothrombin time) in males was recorded in all dose levels. 
Haematological examination - females Statistically significant values in red and white blood components were recorded almost only in females at the dose level 1000 mg/kg/day.
The value of WBC was dose dependently increased in all dosed females; at the dose 500 and 1000 mg/kg/day statistically significantly. This increasing was irreversible – persisted in satellite treated females.
Statistically significantly decreased value of Hgb, Hct (haematocrite)
Increased value of Plt were also recorded at the highest dose level.
Prolonged APTT (activated partial thromboplastin time) in all dose levels and increased value of fibrinogen in females at the dose level 500 and 1000 mg/kg/day were recorded as statistically significantly changed parameters.
Blood urea nitrogen The examination did not show differences related with the test item treatment
Biochemical examination - males
Statistically significantly increased values of calcium (Ca), phosphorus (IP) and bile acid (BA) were recorded in all dosed groups of males in comparison with the control group. 
Statistically significantly increased of the value of HDL cholesterol in males at the dose level 500 and 1000 mg/kg/day.
Statistically significantly increased of the vhe value of TG in males at the dose level 500 mg/kg/day.
All changes were reversible – not recorded in satellite treated group of males at the end of recovery period.
An irreversible change in concentration of natrium ions was observed. The value of Na+ was significantly increased in males at the dose level 1000 mg/kg/day and was recorded also at the end of recovery period in satellite treated group of males.
Biochemical examination - females
Statistically significantly increased values of triglycerides (TG), phosphorus (IP) and decreased value of cholinesterase (CHE) in females at the dose level 500 and 1000 mg/kg/day.
Statistically significantly increased value of calcium ions (Ca) and HDL cholesterol in females at the dose level 500 mg/kg/day. Sigificant decrease of the value of creatinine (Crea) in females at the dose 250 and 500 mg/kg/day.
All changes were reversible – not recorded in satellite treated group of females at the end of recovery period.
Urinalysis The urine examination showed significant differences in pH value related to the test item treatment. Changes in urine parameters can be considered treatment related and correspond to the test item character (acid).
Organ weights - males In males, increased absolute weights of adrenal glands was recorded only at 1000 mg of a.i./kg/day.
Statistically significantly changed relative weight of organs in treated males was observed only in males at 1000 mg of a.i./kg/day. Increased of the relative weight of adrenal glands, testes and brain.
Organ weights - females Dose-dependent increase of absolute and relative weight of liver was observed.
Statistically significantly changed weight of liver in females at the dose levels 500 and 1000 mg of a.i./kg/day.
No histopathological findings corelated with increased weight of liver were recorded.
Biometry of organs The evaluation of the biometry of organs did not show differences related with the test item treatment. Because no histopathological findings correlated with changed weight of organs were recorded, all changed values were considered not of to be biologically or toxicologically significant.
Sperm analisys Sperm analysis did not show negative effect of the test item treatment on males. A comparison of sperm motility in the control males and males from treated groups did not show differences. The test item treatment did not affect sperm morphology.
Necropsy evaluation Macroscopic findings on stomach mucosa related to the test item administration were recorded only in animals of the highest dose level (1000 mg of a.i./kg/day). 
Histopathological examination No histopathological changes in the animal´s liver and kidneys indicative of a toxic effect.
No histopathological findings on the organs of the hematopoietic and lymphatic systems.
No histopathological findings of bone marrow were observed.
No findingis in the histological evaluation of thyroid gland.
Histopathological examination on stomach mucosa showed findings that indicate a toxic negative effect of the test item on a stomach of dosed animals. The described lesions accompanied by minimal to mild focal hyperplasia of the forestomach mucosa were revealed in the most of high dose rats.
Thyroid Hormones - males Statistically significant differences in concentrations of T4 and TSH hormone were not detected.
Concentration of T3 hormone was significantly increased in males at the dose levels 500 and 1000 mg/kg/day.
Because no histopathological findings related to the test item administration were reported within the histological evaluation of thyroid gland, these changed values are considered to be an incidental finding.
Thyroid Hormones - females Statistically significant differences in concentrations of T3 and TSH hormone were not detected.
Concentration of T4 hormone was statistically significantly decreased in females at the dose level 500 mg/kg/day. 
Because no histopathological findings related to the test item administration were reported within the histological evaluation of thyroid gland, these changed values are considered to be an incidental finding.

Applicant's summary and conclusion

Conclusions:
NOAEL (No Observed Adverse Effect Level) for REPEATED DOSE TOXICITY (90 days) is < 250 mg of a.i./kg body weight/day for both amles and females rats.
Executive summary:

The test item, 4-hydroxybenzenesulphonic acid, was tested for Repeated Dose Toxicity Study (90 days do administration) following OECD 408.

All findings of treated groups of animals were compared to the control group of animals.

During the study two males died but this is considered incidental. No effects on behaviour and ophthalmological examination. The test item administration caused negative effects on body weight and on water consumption in males. Haematological and biochemical examination showed changes both in male and females in some parameters, this is considered as an adaptive response to the test item administration. Concentration of T3 and T4 hormone was significantly increased respectively in males and females. Because no histopathological findings related to the test item administration were reported within the histological evaluation of thyroid gland, these changed values are considered to be an incidental finding.

The results of urinalysis showed significant differences in pH value related to the test item treatment due to the test item character (acid). The evaluation of the biometry of organs did not show differences that were considered related to test item treatment. No histopathological findings that correlated with organ weight changes were recorded, therefore all changes were considered not of to be biologically or toxicologically significant. Macroscopic findings on stomach mucosa related to the test item administration were recorded. This was confirmed by histopathological examination, where the findings indicate a toxic negative effect of the test item on a stomach of dosed animals.Test item did not cause histopathological changes in the animal´s liver and kidneys indicative of a toxic effect. Histological examination revealed no histopathological findings on the organs of the hematopoietic and lymphatic systems. Also, no significant differences in histopathological findings of bone marrow were observed between control and high dose rats. Other lesions found in the treated animals were either of spontaneous character or they were not in direct relation with the test item administration.