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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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 vivo
Type of information:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
supporting study
Study period:
1982
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:
study report
Title:
Unnamed
Year:
1982
Report date:
1982

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
The substance was applied to the shaved back skin of rats. The animals were housed in metabolic cages to collect urine and faeces. After 48 h the rats were euthanised and the substance was measured in urine and faeces, in the skin of the application area and in the remaining body.
GLP compliance:
no

Test material

Constituent 1
Reference substance name:
(1-hydroxyethylidene)bisphosphonic acid, sodium salt
EC Number:
249-559-4
EC Name:
(1-hydroxyethylidene)bisphosphonic acid, sodium salt
Cas Number:
29329-71-3
Molecular formula:
C2H8O7P2.xNa
IUPAC Name:
(1-hydroxyethylidene)bisphosphonic acid, sodium salt
Test material form:
not specified
Radiolabelling:
yes
Remarks:
14C

Test animals

Species:
rat
Strain:
Wistar
Sex:
male
Details on test animals or test system and environmental conditions:
weight: 220-260 g
caging in open metabolic cages at a room temperature of 20 °C
feed (Altromin 1324) and water ad libitum

Administration / exposure

Type of coverage:
other: glass capsule with holes, allows gas exchange but prevents the rats to lick off the substance
Vehicle:
water
Duration of exposure:
48 h
Doses:
0.2 g of a 1 % solution
No. of animals per group:
10
Control animals:
no

Results and discussion

Signs and symptoms of toxicity:
not specified
Dermal irritation:
not specified
Total recovery:
81.5 %
Percutaneous absorption
Dose:
0.1 %
Parameter:
percentage
Absorption:
0.46 %
Remarks on result:
other: 48 h

Any other information on results incl. tables

The absorbed radioactivity was mostly eliminated via faeces (0.082 %), while a minor part was eliminated via urine (0.025 %). Elimination via faeces was similar in both collection periods (0 - 24 h and 24 - 48 h), while elimination via urine was predominantly found in the first collection period. After 48 h a mean of 0.339 % of the applied radioactivity could be found in the remaining carcass.

Applicant's summary and conclusion

Conclusions:
The absorption of sodium HEDP is very low (0.46 %).
Executive summary:

Cutaneous absorption and elimination of sodium HEDP was determined in male rats. The measurements were performed with 14C labelled CA 2. The radioactive substance was applied as a 1 % solution to the shaved back skin of rats. Absorption and elimination was measured after 48 h. After this time, 0.46 % of the applied radioactivity was absorbed. This shows that sodium HEDP is absorbed poorly. The main route of elimination was via faeces. Most of the absorbed amount (0.34 %) could be found in the remaining carcass (excluding the skin of the application area) at the end of the test. This may suggest a delayed elimination and probably an accumulation in the bones.