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Administrative data

Endpoint:
sub-chronic toxicity: oral
Type of information:
experimental study
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:
2005
Report date:
2005

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:
3-(2-hydroxyethyl)-p-phenylenediammonium sulphate
EC Number:
298-995-1
EC Name:
3-(2-hydroxyethyl)-p-phenylenediammonium sulphate
Cas Number:
93841-25-9
Molecular formula:
C8H12N2O.H2O4S
IUPAC Name:
2-(2,5-Diaminophenyl)ethanol sulfate (1:1)
Specific details on test material used for the study:
Batch number : 36/37
Purity : 99.8a/a%

Test animals

Species:
rat
Strain:
other: CRL : (WI) BR Wistar
Sex:
male/female

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
other: 1% aqueous methylcellulose
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
The concentration of dosing suspensions was analysed on days 0, 7 and 90.
Duration of treatment / exposure:
90 days
Frequency of treatment:
Once daily
Doses / concentrationsopen allclose all
Dose / conc.:
25 mg/kg bw/day (actual dose received)
Dose / conc.:
35 mg/kg bw/day (actual dose received)
Dose / conc.:
55 mg/kg bw/day (actual dose received)
No. of animals per sex per dose:
Twenty animals (10 males and 10 females) per dose group
Control animals:
yes, concurrent vehicle
Details on study design:
Animals were treated daily for 90 consecutive days by oral gavage with the test item at a dose of 0, 25, 35 and 55 mg/kg bw/day. This dose range was based on data from a preliminary study which showed that a dose of 75 mg/kg bw/day caused significant body weight stagnation, body weight gain depression and decreased food consumption. In the range finding study, the test item was found to cause an increase in AST activity at dose levels of 40 mg/kg bw/day (in females) and 60 mg/kg bw/day (in males and females). In the 90 day oral toxicity study the test item was prepared in 1% aqueous methylcellulose, corresponding to a constant treatment volume of 10 mL/kg bw.

Examinations

Observations and examinations performed and frequency:
Mortality and morbidity of treated animals were checked twice daily, clinical observations were made once per day. Once before the first exposure, once a week thereafter and once on week 12, a functional observation battery test (evaluation of hearing reaction, visual and proprioceptive stimuli and assessment of grip strength and motor activity) was undertaken. Ophthalmoscopy was performed before treatment, in the control group and in the 55 mg/kg bw/day dose group on week 12. Haematological examinations and clinical biochemical analyses were conducted before the first treatment and one day after the last treatment. Urinalysis was performed in week 11.
Sacrifice and pathology:
Sacrificed animals were subjected to necroscopy including gross pathological examination, organ weight determination and histopathology.

Results and discussion

Results of examinations

Clinical signs:
no effects observed
Description (incidence and severity):
Clinical symptoms related to a toxic effect of the test item were not found. The general state, behaviour of all animals were normal during the 90 day treatment period. No difference was found between the experimental groups in the sensory reactivity to stimuli of different types, in the grip strength and motor activity before treatment, one week thereafter and at termination of the study.
Mortality:
no mortality observed
Body weight and weight changes:
no effects observed
Description (incidence and severity):
The body weight development was unaffected by the test item.
Food consumption and compound intake (if feeding study):
no effects observed
Description (incidence and severity):
The mean daily food intake was comparable in the control and dosed groups.
Ophthalmological findings:
no effects observed
Haematological findings:
no effects observed
Clinical biochemistry findings:
effects observed, treatment-related
Description (incidence and severity):
In the 55 mg/kg bw/day dose group test item related increased activity of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) was found in male and especially female animals with statistical and biological significance. No damage of the liver cells was found microscopically.
Urinalysis findings:
no effects observed
Behaviour (functional findings):
no effects observed
Organ weight findings including organ / body weight ratios:
no effects observed
Description (incidence and severity):
The weight of selected organs was not influenced by 90 day treatment with the test item.
Gross pathological findings:
no effects observed
Description (incidence and severity):
Test item or treatment related macroscopic alterations of organs and tissues were not observed.
Details on results:
No clinical signs were recorded which were considered to be related to a toxic effect of the test substance. No difference was found between the experimental groups with respect to performance in the functional observational test battery before starting the study, one week thereafter and at termination of the study. Effects on body weight gain were observed but these effects were not dose related. Mean daily food consumption was comparable between the control and the dose groups. Ophthalmoscopy did not show any test item related effects. Haematology showed some variations in RC, PT, WBC, SE, LY and RBC but these effects were not dose related. In the 55 mg/kg bw/day dose group, a test item related and statistically and biologically significant increase in activity of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) was found in male and especially female animals. Histopathology did not reveal dose related lesions of the examined organs.

Effect levels

Dose descriptor:
NOAEL
Effect level:
35 mg/kg bw/day (actual dose received)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: liver function

Target system / organ toxicity

Critical effects observed:
no

Applicant's summary and conclusion

Conclusions:
Hydroxyethyl-p-phenylenediamine sulfate induced an increase in the aspartate aminotransferase and alanine aminotransferase activities in CRL:(WI) BR rats at a dose of 55 mg/kg bw/day. The NOAEL in the study was 35 mg/kg bw/day.
Executive summary:

A toxicity study was performed according to OECD guideline 408 to characterise possible adverse or toxic effects of test item hydroxyethyl-p-phenylenediamine sulfate (Betoxol II) following oral administration in rats at three dose levels for 90 consecutive days. Dose groups of ) (vehicle only), 25 mg/kg bw/day, 35 mg/kg bw/day and 55mg/kg bw/day were employed in the study. CRL:(WI)BR rats (10/sex/group) were treated daily by gavage with the test item in concentrations of 2.5 mg/mL, 3.5 mg/mL and 5.5 mg/mL prepared in 1% aqueous methylcellulose. These concentrations correspond to a constant treatment volume of 10mL/kg bw. Concentration of dosing suspensions was analysed on days 0, 7 and 90. The measured concentrations were within a +/-4% range of nominal concentrations in each case. Formulations were stable after storage at 22 +/-3 deg C for 4 hours. Clinical observations were made once daily. Functional observation battery was conducted in all animals before the first exposure, once a week thereafter and on week 12. Eyes of all animals were examined before treatment and in the control and high dose groups on week 12. The body weight and food consumption were measured weekly. Urinalysis was performed on week 11. Blood sampling for laboratory examination and gross pathology was conducted one day after the last treatment. Selected organs were weighed. A full histopathological examination was made in all experimental groups. Clinical symptoms related to a toxic effect of the test item were not found. The general state, behaviour of all animals were normal during the 90 day treatment period. No difference was found between the experimental groups in the sensory reactivity to stimuli of different types, in the grip strength and motor activity before treatment, one week thereafter and at termination of the study.The body weight development was unaffected by the test item. The mean daily food intake was comparable in the control and dosed groups. No alterations in ophthalmoscopy were found in the examined high dose groups in both sexes. No test item related alterations were observed in the examined haematological parameters. In the 55 mg/kg bw/day dose group test item related increased activity of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) was found in male and especially female animals with statistical and biological significance. No damage of the liver cells was found microscopically. Urine parameters were between physiological (historical control) ranges in all experimental groups. Test item or treatment related macroscopic alterations of organs and tissues were not observed. The weight of selected organs was not influenced by 90 day treatment with the test item. Histopathological lesions of the examined organs attributed to the test item were not found. Hydroxyethyl-p-phenylenediamine sulfate (Betoxol II) influenced the liver function since an increase in the AST and ALT activities was observed after 90 consecutive days of oral administration to CR:(WI)BR rats at a dose of 55 mg/kg bw/day. The NOEL in the study was 35 mg/kg bw/day.