Registration Dossier

Administrative data

Endpoint:
dermal absorption in vitro / ex vivo
Type of information:
experimental study
Adequacy of study:
other information
Study period:
1994
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: experimental study, not guideline conform, only one concentration tested

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
1994
Report Date:
1994

Materials and methods

Principles of method if other than guideline:
in vitro skin permeability
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid
Details on test material:
- Name of test material (as cited in study report): 1,3-butylene glycol
Radiolabelling:
no

Test animals

Species:
rat
Strain:
other: WBN/ILA-Ht
Sex:
male
Details on test animals and environmental conditions:
- aged 6-7 weeks
- abdominal skin, freshly excised

Administration / exposure

Details on in vitro test system (if applicable):
- freshly excised skin from male rats was mounted between two half-diffusion cells with water jacket connected to a water bath at 37°C
- volume of each cell: 2.5 ml
- effective diffusion area: 0.966 square centimetre
- receiver compartment: filled with distilled water
- donor compartment: filled with D2O containing a test item and inulin
- application amount: 10 mg/ml
- inulin was used as volume marker at 0.2 mg/ml
- osmotic-pressure differential was adjusted to 3.08, 0 and -3.08 osmol/l by the addition of NaCl to donor or receiver compartments
- donor and receiver solutions were stirred
- at certain intervals aliquots were withdrawn from the receiver and receiver solution added to keep the volume constant
- determination of test item concentration: gas chromatograph

Results and discussion

Applicant's summary and conclusion

Conclusions:
In vitro investigations with abdominal skin of rats indicate that 1,3-butylene glycol can penetrate the skin and the penetration rate was comparable to ethylene glycol.
Executive summary:

In vitro investigations on skin permeability of 1,3-butylene glycol with abdominal skin of rats showed that the test item can penetrate the skin.Values for permeation clearance were between 2.5 to 7.5 µg/h. These data were comparable to the values obtained with ethylene glycol, which was tested under identical conditions (Hatanaka et al., 1994).

The study allows for the reliable comparison with the well characterised ethylene glycol under identical experimental conditions.