1,3-dimethyl-1,3-diphenylurea

Endpoint summary

Link to relevant study record(s)

Reference

Endpoint:

basic toxicokinetics

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

March - September 2012

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: According to the ECHA guidance “Practical guide 6" the reliability was changed to RL2 to reflect the fact that this study was conducted on a read-across substance.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across: supporting information

Objective of study:

toxicokinetics

Qualifier:

no guideline required

Principles of method if other than guideline:

Assessment from available information, which meets generally accepted scientific method and is described in sufficient detail.

Conclusions:

Overall low acute oral toxicity of Centralit was found, but the absorption to the mammalian body occurs. At lethal doses the Central nervous system disturbances, tremors, lethargy, tonic convulsions were seen. There are marked differences in toxicity between sexes, the males are much more resistant and they stand alive at doses which are distinctly lethal to females. If it could be by caused by differences in absorption is unknown.
Sex differences in susceptibility to toxic effects of Centralite were noted also in studies with repeated administration. In these the effect on neural system of animals is manifested as Straub phenomenon in first days of administration. This reaction is similar for animals after application of opiate substance, e.g. morphine. During next weeks of study, these changes were not observed any more, which can relate with adaptation of organism of treated animals to the test substance. Everything written above reads for females. In males no such distinct reaction was observed. But in both sexes the effect on liver weight and function, changes in some blood parameters and plasma enzymes were noted.
Administration of Centralit had no adverse effect to ability of male and female animals to successfully mate and produce viable offspring. No signs of any gonadotropic or mutagenic effects were found.

Finally it could be concluded that Centralit after oral administration is absorbed into body of animals, metabolized in liver and either per se or as metabolites is rapidly distributed to CNS. It is questionable if it could reach also the reproduction organs.
The absorption through skin or eye mucosa is much less probable. Respiratory tract absorption could occur but the efficiency of this process is not known.
No information was found about the metabolism and elimination of Centralit.

Description of key information

Assessment of the toxicokinetic behaviour of the substance from the relevant available information was performed.

The evaluation of toxicokinetics is based on information from three sources:

 - Experimental data of toxicological tests

 - Literature data obtained from internet

 - Data from toxicological databases – free and commercial

Key value for chemical safety assessment

Bioaccumulation potential:

no bioaccumulation potential

Absorption rate - oral (%):

100

Absorption rate - dermal (%):

100

Absorption rate - inhalation (%):

100