Registration Dossier

Administrative data

Endpoint:
dermal absorption in vitro / ex vivo
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
01.10.1999 to 30.06.2000
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

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

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: Bronaugh Flow Through method
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Radiolabelling:
yes
Remarks:
14C-hexamethyldisiloxane (14C-HMDS)

Test animals

Species:
human
Strain:
other: N/A
Sex:
male/female

Administration / exposure

Type of coverage:
semiocclusive
Vehicle:
unchanged (no vehicle)
Duration of exposure:
24 hours
Doses:
Neat-14C-hexmethyldisloxane, 9 mg/cm2 of skin; radioactivity for each skin was 6 uCi.
No. of animals per group:
5 males, 1 female
Control animals:
no

Results and discussion

Percutaneous absorption
Dose:
9 mg/cm2
Parameter:
percentage
Absorption:
ca. 0.023 %
Remarks on result:
other: 24 hours
Remarks:
The majority (75%) of the absorbed dose was found in the skin, and the majority (98%) of the applied dose evaporated from the application site.

Any other information on results incl. tables

The statistical analysis of the data indicated that only 0.023% of the applied dose of neat HMDS was absorbed at the end of the assay (standard error of the mean =0.011% of applied dose). The majority of the absorbed HMDS (75.07%) was found in the skin. The percent of applied dose recovered from all analyzed samples for neat HMDS was 97.58 +/- 0.351%. The majority of the applied dose (97.51 +/- 0.357%) volatilised from the dosing site and was collected in the charcoal basket.

Applicant's summary and conclusion

Conclusions:
In a well conducted in vitro dermal absorption study conducted to GLP (reliability score 1), a statistical analysis of the data indicated that only
0.023% of the applied dose of hexamethyldisiloxane was absorbed through human cadaver skin. The majority of the dose volatilised from the application site (97.5%).