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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:
key study
Study period:
1990
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Acceptably documented study which meets basic scientific principles and contains sufficient detail to be able to judge the results reliable as a contribution to the understanding of the toxicokinetics of this substance.

Data source

Reference
Reference Type:
publication
Title:
Triethylene glycol ethers: Evaluation of in vitro absorption through human epidermis, 21 day dermal toxicity in rabbits and a developmental screen in rats
Author:
Leber AP, Scott RC, Hodge MCE, Johnson D, Krasavage WJ
Year:
1990
Bibliographic source:
J Am Coll Toxico, 9 (5) 507-15

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 428 (Skin Absorption: In Vitro Method)
Deviations:
not specified
Principles of method if other than guideline:
The study seems to follow main requirements of the OECD protocol although not all information is included in publication to judge if it is followed exactly. Further reference given to the method of Dugard et al (Env Hlth Persp, 17, 193, 1984)
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Poly-solv TB
- Physical state: liquid
- Analytical purity: 99.9% pure
- Supplier: Olin Corporation, New Haven, CT

- Control substance: Ethylene glycol monomethyl ether, ex ICI, UK. 100% pure.
Radiolabelling:
no

Test animals

Species:
human
Strain:
other: human
Sex:
female

Administration / exposure

Vehicle:
other: 0.9% saline
Control animals:
no
Details on in vitro test system (if applicable):
SKIN PREPARATION
- Source of skin: human, obtained post mortem, predominantly from females of varied age.
- Ethical approval if human skin:
- Type of skin: whole skin (dermis plus epidermis)
- Preparative technique: samples of epidermis separated from dermis following immersion in water at 60C for 45-60s.
- Membrane integrity check: tested using tritiated water in 0.9% saline monitored over 3-6 hours

PRINCIPLES OF ASSAY
- Diffusion cell: Epidermal sample mounted in a glass diffusion apparatus. 2.54cm2 area of exposure. Measurements made over 12 hours in triplicate
- Receptor fluid: 0.9% saline
- Solubility od test substance in receptor fluid: fully miscible
- Reference substance(s): ethylene glycol methyl ether

Results and discussion

Absorption in different matrices:
An in vitro study determined that the permeability of 2-(2-(2-butoxyethoxy)ethoxy)ethanol to human skin is quite low. The permeability co-efficient was determined to be 22 +/-8.6ug/cm2/hr, which is around 1% of the skin penetration rate of the shorter chain glycol ether ethylene glycol methyl ether. Exposure to the substance also caused no significant deterioration of skin barrier properties.

Any other information on results incl. tables

Human abdominal whole skin (2.54 cm sq) was mounted in a glass diffusion apparatus (at 30 +/- 1 degree C) and the diffusion of triethylene glycol monobutyl etherwas monitored during a 12-hr period using gas chromatography (n=6). The integrity of the epidermal membranes was first assessed by measuring permeability of membranes to tritiated water. Epidermal membranes displaying permeability constants greater than 1.5 x 10E-3 cm/hr were deemed to have been damaged during preparation and were rejected. The mean steady state of absorption for triethylene glycol monobutyl ether was 22.2 ug/cm sq/hr (SD +/- 8.59), which was 100-fold less than that of ethylene glycol monomethyl ether. Test material did not increase permeability of the membrane (damage ratio of 1.26).

Applicant's summary and conclusion

Conclusions:
An in vitro study determined that the permeability of 2-(2-(2-butoxyethoxy)ethoxy)ethanol to human skin is quite low. The permeability co-efficient was determined to be 22 +/-8.6ug/cm2/hr, which is around 1% of the skin penetration rate of the shorter chain glycol ether ethylene glycol methyl ether. Exposure to the substance also caused no significant deterioration of skin barrier properties.
Executive summary:

An in vitro study determined that the permeability of 2-(2-(2-butoxyethoxy)ethoxy)ethanol to human skin is quite low. The permeability co-efficient was determined to be 22 +/-8.6ug/cm2/hr, which is around 1% of the skin penetration rate of the shorter chain glycol ether ethylene glycol methyl ether. Exposure to the substance also caused no significant deterioration of skin barrier properties.