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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Endpoint:
additional toxicological information
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: The study was well documented and meets generally accepted scientific principles, but was not conducted in compliance with GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2000
Report date:
2000

Materials and methods

Principles of method if other than guideline:
Evaluation of D5 as a potential inhibitor of human and rat cytochrome P450 enzymes.
GLP compliance:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
Decamethylcyclopentasiloxane
EC Number:
208-764-9
EC Name:
Decamethylcyclopentasiloxane
Cas Number:
541-02-6
Molecular formula:
C10H30O5Si5
IUPAC Name:
2,2,4,4,6,6,8,8,10,10-decamethyl-1,3,5,7,9,2,4,6,8,10-pentoxapentasilecane

Results and discussion

Any other information on results incl. tables

D5 appears to inhibit rat CYP2B1/2 in a manner that does not conform to prototypical  types of inhibition; this inhibition increases significantly with an increase in marker substrate concentration. D5 also appears to be a weak competitive inhibitor of human  CYP3A4/5 and a strong metabolism-dependent inhibitor of human CYP3A4/5.

Applicant's summary and conclusion

Conclusions:
In an in vitro study that investigated whether D5 is a potential inhibitor of human and rat cytochrome P450 enzymes it was found that D5 appears to inhibit rat CYP2B1/2 in a manner that does not conform to prototypical  types of inhibition; this inhibition increases significantly with an increase in marker substrate concentration. D5 also appears to be a weak competitive inhibitor of human  CYP3A4/5 and a strong metabolism-dependent inhibitor of human CYP3A4/5.