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Toxicological information

Dermal absorption

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Administrative data

Endpoint:
dermal absorption in vitro / ex vivo
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
no data available
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Well documented and scientifically acceptable.

Data source

Reference
Reference Type:
publication
Title:
Permeabilty of human skin to selected anions and cations - in vitro studies.
Author:
Laudanska, H.; et al.
Year:
2002
Bibliographic source:
Res. Communications Molecular Pathol. Pharmacol., 16-26

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Estimation whether magnesium ions (Mg2+) and calcium ions (Ca2+) are able to pass through isolated patches of human skin and investigation of the dynamics of ion diffusion.
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Type:
Constituent
Type:
Constituent
Type:
Constituent
Details on test material:
Common name: calcium chloride anhydrans
- Name of test material (as cited in study report): calcium chloride anhydrans
- Physical state: solid
- Name of test material (as cited in study report): magnesium sulfate heptahydrate
- Physical state: solid
Radiolabelling:
no

Test animals

Species:
human
Strain:
other: not applicable, human tissue
Sex:
not specified
Details on test animals and environmental conditions:
not applicable, since no test animals were used

Administration / exposure

Type of coverage:
other: in solution
Vehicle:
physiological saline
Duration of exposure:
20 hours at 37 °C for each experiment.
Doses:
Concentrations of 2.0 and 7.6 mg Ca2+/L or 0.3 and 2.1 mg Mg2+/L were tested
No. of animals per group:
not applicable
Control animals:
no
Details on study design:
DOSE PREPARATION
no data
APPLICATION OF DOSE:
in solution
VEHICLE
no further details as described in the field "Vehicle"
TEST SITE
not applicable
SITE PROTECTION / USE OF RESTRAINERS FOR PREVENTING INGESTION: no (not applicable)
REMOVAL OF TEST SUBSTANCE
not applicable
SAMPLE COLLECTION
not applicable
SAMPLE PREPARATION
- Storage procedure: Samples were frozen in -20°C and stored for discriminations.
- Preparation details: no data
ANALYSIS
Ion chromatography method was used to determine cation and anion levels. Ion chromatograph Metrohm operated with Metrodata 714 IC version 2.06 software equipped with Super SEP anionic and cationic
columns was applied.
OTHER:
no further details
Details on in vitro test system (if applicable):
SKIN PREPARATION
- Source of skin: Human skin samples from mammectomised breasts of 27 breast cancer patients, aged 34 to 55 years.
- Ethical approval if human skin: The study was approved by University Ethic Committee.
- Preparative technique: A dermatome was used to sample the skin in all cases.
- Thickness of skin (in mm): 0.5
- Storage conditions: Skin samples were transported in ice-cold saline and frozen (-20 °C) until used in the experiments. Storage did not exceed 3 weeks.
PRINCIPLES OF ASSAY
- Diffusion cell: Each of 3 systems consisted of dual (transmission and reception chamber of 20 mL volume, respectively) diffusion chambers. A fraction collector and a peristaltic pump were attached to each
system.
- Receptor fluid: Isotonic saline solution.
- Test temperature: 37 °C
- Other: For each of the ions, 5 to 8 experiments were performed resulting in a total of 27 experiments; samples for analysis were taken at 60-minute intervals.

Results and discussion

Signs and symptoms of toxicity:
not specified
Dermal irritation:
not specified
Absorption in different matrices:
not applicable
Total recovery:
no data
Percutaneous absorption
Remarks on result:
other: not determined
Conversion factor human vs. animal skin:
not examined

Any other information on results incl. tables

The aim of the study was to exemplify the changes in ion concentrations in the first 20 hours of perfusion. In this study it was shown that human skin, under in vitro conditions, was permeable to calcium ions. Continuous sampling of solution performed in 1-hour intervals and consecutive refilling the chamber with equal volume of perfusion solution would lead to gradual steady decrease in concentration in the reception chamber.

Applicant's summary and conclusion

Conclusions:
Human skin is permeable to magnesium and calcium ions at concentrations comparable to those found in rainwater from Polish regions with different levels of air pollution. However, specific dermal dermal absorption rates cannot be derived from the parameters reported.