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Toxicological information

Dermal absorption

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Administrative data

Endpoint:
dermal absorption in vitro / ex vivo
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
2002
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:
publication
Title:
Unnamed
Year:
2002

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 428 (Skin Absorption: In Vitro Method)
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Test material form:
other: liquid
Details on test material:
- Name of test material (as cited in study report): Lauryl methacrylate
Supplier: Röhm GmbH
- Lot/batch No.: 780803361
Physical state: liquid
Radiolabelling:
no

Test animals

Species:
rat
Strain:
Wistar
Sex:
male
Details on test animals and environmental conditions:
Collection and preparation of rat skin for epidermal membrane absorption studies:
Skin was used from male rats of the Wistar-derived strain (supplied by Charles River UK Ltd, Margate, Kent, UK.) aged 28 days ± 2 days. Fur from the dorsal and flank region was carefully shaved using animal clippers, ensuring that the skin was not damaged. The clipped area was excised and any subcutaneous fat removed. The skins were soaked for approximately 20 hours in 1.5M sodium bromide then rinsed in distilled water. The epidermis was carefully peeled from the dermis. Each epidermal membrane was given an identification number and stored frozen on aluminium foil until required for use.
 
Collection and preparation of rat skin for whole skin absorption studies:
Skin was taken from male Fisher F344 (supplied by Harlan Olac) rats weighing between 200 and 250 g. Fur from the dorsal and flank region was carefully shaved using animal clippers, ensuring that the skin was not damaged. The clipped area was excised and any subcutaneous fat removed. Each skin membrane was given an identification number and immediately assembled into diffusion cells and their integrity checked.

Administration / exposure

Type of coverage:
open
Vehicle:
unchanged (no vehicle)
Duration of exposure:
48 hrs
Doses:
100 µL/cm²
Details on study design:
The absorption of Lauryl methacrylate was evaluated through rat epidermis and intact skin in an in vitro system. Values for human skin absorption were extrapolated on the basis of a 14 times more efficient permeation through rat skin obtained in an epidermal PB-PK model developed in this study.
Details on in vitro test system (if applicable):
Assembly of the diffusion cells:
The type of glass diffusion cell has an exposed membrane area of 2.54 cm². Discs of approximately 3.3 cm in diameter were cut from the prepared skin and membrane from at least three individuals (two in the case of human skin) were mounted, dermal side down, in diffusion cells held together with individually numbered clamps.

Results and discussion

Signs and symptoms of toxicity:
not examined
Dermal irritation:
not examined
Absorption in different matrices:
Absorption of Lauryl methacrylate through rat epidermis:

The substance is readily absorbed through rat epidermis at a constant mean rate of 26.2 µg/cm²/hr.
This rate of absorption are virtually constant over the duration of the experiment.
The total amount of chemical that was absorbed during the time of exposure was 0.7 % of the applied dose.

Absorption of Lauryl methacrylate through whole rat skin:

Like the smaller esters investigated, Lauryl methacrylate was also metabolised to methacrylic acid as it was absorbed through whole rat skin. the peak rate of appearance of methacrylic acid was calculated to be 11.8 µg/cm²/hr, which occurred between 8 and 24 hours.
0.264 % of the Lauryl methacrylate was depleted from the donor reservoir over the 24 hr exposure period.
Percutaneous absorptionopen allclose all
Time point:
24 h
Dose:
100 µL/cm²
Parameter:
percentage
Absorption:
0.7 %
Remarks on result:
other: Rat epidermis
Time point:
24 h
Dose:
100 µL/cm²
Parameter:
percentage
Absorption:
0.264 %
Remarks on result:
other: whole rat skin
Conversion factor human vs. animal skin:
With respect to human skin, 14 times more efficient permeation through rat skin obtained in an epidermal PB-PK model developed in this study.

Applicant's summary and conclusion