(E)-3-(benzyl(4-((4-nitrophenyl)diazenyl)phenyl)amino)propanenitrile

Endpoint summary

Link to relevant study record(s)

Reference

Endpoint:

basic toxicokinetics

Type of information:

calculation (if not (Q)SAR)

Remarks:

Migrated phrase: estimated by calculation

Adequacy of study:

key study

Reliability:

other: A written assessment based on toxicological profile of the substance

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

A written assessment of toxicokinetic behaviour is considered appropriate for the substance. The substance displays only minor toxicological effects in any of the studies proposed, and is deemed to be be not harmful for health effects. As such, it is deemed inappropriate in terms of animal welfare to conduct a toxicokinetic assessment when no harmful effects are predicted based on known toxicology. A written assessment has therefore been prepared to address this endpoint.

Objective of study:

other: Assessment of toxicokinetic behaviour

Principles of method if other than guideline:

Written assessment based on toxicological profile.

GLP compliance:

no

Details on exposure:

Not applicable

Duration and frequency of treatment / exposure:

Not applicable

No. of animals per sex per dose / concentration:

Not applicable

Positive control reference chemical:

Not applicable

Details on study design:

Not applicable

Details on dosing and sampling:

Not applicable

Statistics:

Not applicable

Metabolites identified:

not measured

Details on metabolites:

Not applicable

Conclusions:

Interpretation of results (migrated information): no bioaccumulation potential based on study results

Description of key information

Based on available data, the substance shows moderate oral and low dermal bioavailabilty. The substance does not have bioaccumulative properties.

Key value for chemical safety assessment

Bioaccumulation potential:

no bioaccumulation potential

Additional information

Toxicokinetic parameters such as uptake, distribution, metabolism and excretion form the essential toxicological profile of a substance. An approximate indication of the toxicokinetic pattern can be gained from the physico-chemical properties (solubility in solvents, log P_OW, hydrolytic stability) and the results of basic toxicity testing of the test article. The assessment of the toxicokinetic propertiesof T-9601given below is based on the results obtained for, the following toxicological endpoints:

 

·       Acute oral toxicity in rats

·       Acute dermal toxicity in rats

·       In vivo skin irritation in rabbits

·       In vivo eye irritation in rabbits

·       Skin sensitization in guinea pigs

·       Subacute (28-day) oral toxicity in rats

·       Bacterial reverse mutation test

·       In vitro mammalian cell gene mutation test (HPRT-assay)

·       Chromosome aberration study with mammalian cells in vitro

 

All studies were carried out according to the principles of Good Laboratory Practice and met the requirements of the OECD and EU-Guideline for the Testing of Chemicals.

 

Physico-chemical properties

Physical state:     red powder

Empirical formula:        C₂₂H₁₉N₅O₂

Molecular weight:          385.4 g/mol

Partition coefficient:      log Pow = 4.3;  Pow = 19953 

Melting/freezing point:  ‑157.4°C

Relative Density  1.29 g/cm³

Vapour pressure 1.10^-7hPa at 25°C

Water solubility  0.0017 mg/l 

 

Toxicological Profile

 

After single oral administration of T-9601 at a dose level of 2000 mg/kg body weight to male and female rats neither deaths nor significant adverse symptoms occurred. Similarly, single dermal application of 2000 mg/kg body weight onto male and female rats produced no deaths or symptoms of systemic toxicity. Test item relatedorange staining of the treated area was observed up to and including Day 6.The median lethal dose (LD₅₀) of T-9601 after oral and dermal administration to rats is greater than 2000 mg/kg body weight.

Testing for skin and eye irritating properties of T-9601 in rabbits did not lead to any sign of irritation. Consequently, T-9601 is not irritating to skin or eyes according to the classification criteria of Directive 2001/59/EC orRegulation (EC) No 1272/2008.

Testing for sensitizing properties of T-9601 was performed in the Guinea Pig Maximization Test in female guinea pigs. No evidence of skin sensitizing properties was found.

To assess the toxicity of T-9601 after repeated administration, male and female rats received the test substance at dose levels of 62.5, 250, or 1000 mg/kg body weight per day for a period of 28 days by oral gavage followed by a 14-day recovery phase (controls and high dose animals).

No deaths occurred throughout the study. Behavior and state of health remained unaffected by the administration of the test compound in all dose groups. Neurotoxicological parameters remained unaffected by the administration of the test-compound in all groups. Body weight development, food and water consumption remained unaffected by the administration of the test compound in all groups. Hematological examination of the final values revealed slightly decreased red blood cell counts in females from the intermediate and high dose group. Hemoglobin and hematocrit levels were slightly decreased in females from the high dose group. Males from the high dose group showed slightly increased white cell counts. No compound-related changes were observed after the recovery period. Clinical chemistry examinations did not reveal any compound-related effect. Urine was discolored dark yellow in both sexes from the high dose group. Remaining urine parameters and urine sediments did not reveal any compound-related change. Liver weights were slightly increased in males from the intermediate and high dose group. These changes were no longer observed at the end of the recovery period. Yellow discoloration of adipose tissue was observed at necropsy in all dose groups. This finding was reversible by the end of the recovery period in males, but still present in females. Histopathological examinations did not reveal any compound-related effect.
In conclusion, slight decreases in erythrocyte counts, hemoglobin and hematocrit values were observed in females after repeated oral administration of T-9601 at the daily dose of 1000 mg/kg body weight. Males showed slightly increased liver weights. Slight decreases in erythrocyte counts (females) and slightly increased liver weights (males) were also observed at the daily dose of 250 mg/kg body weight. A compound-related effect cannot be excluded. However, the changes were minor and there were no histopathological correlates for anemia or liver damage. Likewise, clinical chemistry parameters ware inconspicuous, and histopathological examination did not reveal any compound-related effect.

No compound-related adverse effects were observed at the dose level of 62.5 mg/kg body weight per day.

The discoloration of adipose tissue observed at all dose levels is considered not to be of toxicological relevance. With regard to the present study the 'No Observed Effect Level' (NOEL) is 62.5 mg/kg body weight per day. However, no clear toxic effects were observed at the dose levels of 250 and 1000 mg/kg per day.

 

T-9601 was tested for bacterial mutagenicity. The experiments were carried out using histidine-requiring auxotroph strains of Salmonella typhimurium(TA98, TA100, TA1535 and TA1537), and the tryptophan-requiring auxotroph strain of Escherichia coli(WP2 uvrA) in the presence and absence of a metabolic activation system, which is a cofactor-supplemented post-mitochondrial S9 fraction prepared from rat liver.

In the absence and in the presence of the metabolic activation system T-9601 gave a dose-dependent increase in the number of revertant colonies with the Salmonella strains.

The potential of T-9601 to induce gene mutations in mammalian cells was tested at the HPRT locus in Chinese hamster V79 cells in vitro using concentrations up to 1285 µg/ml. The test substance proved to be non-mutagenic in this test system in the presence and in the absence of a metabolic activation system (S9-mix).

T-9601 was assessed for its clastogenic potential in a chromosome aberration study in vitro with V79 cells of Chinese hamster lung fibroblasts. In summary, T-9601 tested both with and without metabolic activation did not induce structural chromosome aberrations in this test system. T-9601 is considered non-clastogenic in this system.

 

Evaluation and Assessment

Examination of the data of the acute dermal toxicity, dermal irritation and skin sensitization studies gave no indication of there being any evidence for skin penetration of the test item. Oral bioavailability of T-9601 is plausible due to the log Po/w of 4.3, since substances with a log Po/w > 0.5 might be significantly absorbed. Bioavailability of T-9601 after oral administration was demonstrated in the subacute 28-day toxicity study at all dose levels (discoloration of fatty tissue). The discoloration of urine observed during treatment in high-dose rats was not longer present after the 14-day recovery period. Likewise, the discoloration of the adipose tissue was completely diminished in recovery males. Hence, there was no indication of bioaccumulation.

Based on the available data, elimination of test compound probably occurs via urine and feces.

 

In summary, based on the results obtained in various toxicological examinations and in the absence of any significant signs of accumulation it can be concluded that T-9601 does not show any toxicokinetic peculiarity.