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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Endpoint:
dermal absorption in vitro / ex vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1995-03-06
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
test procedure in accordance with national standard methods
Remarks:
No controls are used

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1995
Report date:
1995

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
- Principle of test: The diffusion of the test substance through human epidermis was measured via quantitation of the substance in the receptor solution.
- Short description of test conditions: Samples of human epidermis were mounted in glass diffusion cellls over chambers filled with receptor fluid. Test material was applied to the epidermis as a 2% solution in either water or diluted shampoo solution. Half of the cells were occluded for the 30 h exposure, half were occluded for only half an hour. Samples of the receptor solution were taken periodically and analyzed for the test substance.
- Parameters analysed / observed: Samples taken at intervals to measure the amount of test substance in the receptor fluid.
GLP compliance:
yes (incl. QA statement)

Test material

Constituent 1
Chemical structure
Reference substance name:
Hydroxyl-2-pyridone
EC Number:
212-506-0
EC Name:
Hydroxyl-2-pyridone
Cas Number:
822-89-9
Molecular formula:
C5H5NO2
IUPAC Name:
1-hydroxy-1,2-dihydropyridin-2-one
Test material form:
solid: particulate/powder
Specific details on test material used for the study:
- Certificate of Analysis Reference: 9173
- Analytical purity: 99.6% w/w
- Expiration date: not reported
- Storage condition: not reported
STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: not reported
- Stability under test conditions: not reported
- Solubility and stability of the test substance in the solvent/vehicle: not reported
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: not reported
Radiolabelling:
no

Test animals

Species:
other: Human
Sex:
not specified
Details on test animals or test system and environmental conditions:
No details on source

Administration / exposure

Type of coverage:
occlusive
Vehicle:
other: Water or 5% v/v Commercially available shampoo
Remarks:
The shampoo is a straw coloured liquid (Pears Deep Cleansing Shampoo).
Duration of exposure:
1 application, 30 hour exposure. Half of the cells exposed to 2% w/v Oxypyrion in Water and 2% w/v Oxypyrion in Diluted Shampoo were rinsed after 0.5h. After decontamination these membranes were re-occluded for the remainder of the 30h exposure.
Doses:
Nominal doses, for both Continuous Exposure and Rinsed Application:
- 2% w/v Oxypyrion in Water
- 2% w/v Oxypyrion in Diluted Shampoo (consisting of 5% v/v shampoo in distilled water)
No. of animals per group:
12 epidermis cells per vehicle
Control animals:
no
Details on study design:
DOSE PREPARATION
- Method for preparation of dose suspensions: Not described
- Method of storage: Not described

APPLICATION OF DOSE: The test material was applied to the epidermal membranes as 2% w/v solutions in water or diluted shampoo at a rate of 200 µL/cm², using 12 cells for each dosing solution.

REMOVAL OF TEST SUBSTANCE
For half of the cells for each application:
- Washing procedures and type of cleansing agent: decontamination by rinsing with 3 x 5 mL distilled water
- Time after start of exposure: 0.5h after start of exposure

ANALYSIS
- Method type(s) for identification: HPLC
- Limits of detection and quantification: 1 µg/mL
- Column: µBondapak phenyl 10 µm; 300 x 3.9 mm id
- Solvent: Methanol:water (5:95 v/v) containing copper (II) nitrate (0.1 % w/v) and citric acid (0.1 % w/v)
- Flow rate: 1 mL/min
- Detector Wavelenght: 300 nm
- Injection volume: 50 µL
Details on in vitro test system (if applicable):
SKIN PREPARATION
- Source of skin: Not provided
- Ethical approval if human skin: Not provided
- Type of skin: Not provided
- Preparative technique: Extraneous tissue was removed from human whole skin samples. The skin samples were immersed in water at 60°C for 40-45 seconds and the epidermis teased off the dermis.
- Thickness of skin (in mm): Not provided
- Membrane integrity check: Samples of epidermis were mounted in glass diffusion cells and their integrity determined by measurment of their permeability to tritiated water (Dugard et al., 1984). Membranes with a calculated permeability coefficient of <1.5 x 10^-3 cm/h were regarded as being undamaged and used for exposure to the test material.
- Storage conditions: Deep frozen until required for use.
- Justification of species, anatomical site and preparative technique: Not provided

PRINCIPLES OF ASSAY
- Diffusion cell: Not described
- Receptor fluid: distilled water
- Solubility of test substance in receptor fluid: Not described
- Static system: Not described
- Flow-through system: Not described
- Test temperature: Not described
- Humidity: Not described
- Occlusion: Not described
- Reference substance(s): Not described

Results and discussion

Signs and symptoms of toxicity:
not specified
Dermal irritation:
not specified
Absorption in different matrices:
- from the 2% w/v in water continuous experiment, one cell was rejected as contamination was suspected to be present
Percutaneous absorptionopen allclose all
Time point:
10 h
Dose:
mean absorption rate in water, (2.25-10 hr) continuous exposure
Parameter:
rate
Absorption:
5.79 other: µg/cm²/h
Remarks on result:
other: Mean absorption rate between 2.25 and 10 h
Time point:
30 h
Dose:
mean absorption rate in water, (10-30 hr) continuous exposure
Parameter:
rate
Absorption:
7.88 other: µg/cm²/h
Remarks on result:
other: Mean absorption rate between 10 and 30 h
Time point:
10 h
Dose:
mean absorption rate in diluted shampoo, (2.25-10 hr) continuous exposure
Parameter:
rate
Absorption:
5.23 other: µg/cm²/h
Remarks on result:
other: Mean absorption rate between 2.25 and 10 h
Time point:
30 h
Dose:
mean absorption rate in diluted shampoo, (10-30 hr) continuous exposure
Parameter:
rate
Absorption:
11.1 other: µg/cm²/h
Remarks on result:
other: Mean absorption rate between 10 and 30 h
Time point:
6 h
Dose:
mean absorption rate in water, (1-6 hr) rinsed application
Parameter:
rate
Absorption:
0.586 other: µg/cm²/h
Remarks on result:
other: Mean absorption rate between 1 and 6 h
Remarks:
Since the absorption process reached a pleateau by 10h, no steady-state rates of absorption could be calculated for oxypyrion from the rinsed exposures.
Time point:
6 h
Dose:
mean absorption rate in water, (1-6 hr) rinsed application
Parameter:
rate
Absorption:
0.549 other: µg/cm²/h
Remarks on result:
other: Mean absorption rate between 1 and 6 h
Remarks:
Since the absorption process reached a pleateau by 10h, no steady-state rates of absorption could be calculated for oxypyrion from the rinsed exposures.

Applicant's summary and conclusion

Conclusions:
The data obtained in this study predict that during normal use, dermal absorption of oxypyrion through human epidermis would be minimal.