2-ethylhexyl methacrylate

Dermal absorption

Administrative data

Endpoint:

dermal absorption in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

other: Thesis

Title:

Unnamed

Year:

2002

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 428 (Skin Absorption: In Vitro Method)

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

2-ethylhexyl methacrylate

EC Number:

211-708-6

EC Name:

2-ethylhexyl methacrylate

Cas Number:

688-84-6

Molecular formula:

C12H22O2

IUPAC Name:

2-ethylhexyl methacrylate

Test material form:

liquid

Radiolabelling:

no

Test animals

Species:

rat

Strain:

Wistar

Sex:

male

Administration / exposure

Type of coverage:

open

Vehicle:

unchanged (no vehicle)

Duration of exposure:

48 hours

Doses:

100 µl/cm²

Details on in vitro test system (if applicable):

The absorption of 2-EHMA was evaluated through rat and human epidermis in an in vitro system.

Results and discussion

Signs and symptoms of toxicity:

not examined

Dermal irritation:

not examined

Absorption in different matrices:

Absorption of 2-EHMA through rat epidermis:
2-Ethylhexyl methacrylate readily absorbed through rat epidermis at a constant mean rate of 234 µg cm-2 hr-1. This rate of absorption was constant over the whole 30 hour exposure/sampling period. The total amount of chemical that was absorbed during the time of exposure was 7.8% of the donor reservoir.

2-EHMA through human epidermis:
2-ethylhexyl methacrylate appeared to have a lag time between 0 and 3 hrs, where the rate of absorption was calculated to be 7.72 µg cm-2 hr-1. The absorption rate increased to 22.7 µg cm-2 hr-1 and remained linear between 3 and 24 hrs. 0.551% of the applied dose was absorbed over the 24 hours of exposure.

Percutaneous absorption

Percutaneous absorption 1

Dose:

100 µl/cm²

Parameter:

percentage

Absorption:

7.8 %

Remarks on result:

other: 30 hours

Remarks:

Rat epidermis

Percutaneous absorption 2

Dose:

100 µl/cm²

Parameter:

percentage

Absorption:

0.6 %

Remarks on result:

other: 24 hours

Remarks:

Human epidermis

Conversion factor human vs. animal skin:

Human epidermis appears to be 10 times less permeable to 2-EHMA than rat epidermis.

Applicant's summary and conclusion

Conclusions:

2-EHMA readily absorbs through rat and human epidermis. Human epidermis appears to be 10 times less permeable to 2-EHMA than rat epidermis.

Executive summary:

The absorption of 2-EHMA was evaluated through rat and human epidermis in an in vitro system. The technique measures the rate of absorption of 2 -EHMA across the epidermis. Glass diffusion cells are employed to measure the amount of 2 -EHMA that is received into a receptor chamber with respect to time, following the application of 100 µl/cm² of 2 -EHMA to the epidermal surface. The mean rate of absorption was 234 and 7.72 µg cm-2 hr-1 and the total amount of chemical that was absorbed during the time of exposure was 7.8 (over 30 hours) and 0.551% (over 24 hours), respectively. 2-EHMA appears readily absorbed through rat and human epidermis, but human epideremisc is 10 times less permeable to 2-EHMA than rat epidermis. However, measuring the rate of absorption through rat and human epidermis provides a quantitative estimate for inter-species differences; however, because only the epidermal layer is used, no measure of metabolism during skin absorption is possible.