Silver nitrate

Dermal absorption

Administrative data

Endpoint:

dermal absorption in vivo

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1964

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Remarks:

Reasonably well-documented publication, despite major methodological deficiencies.

Data source

Reference

Reference Type:

publication

Title:

A comparative investigation of the percutaneous absorption of metal compounds in the guinea pig by means of the radioactive isotopes: 51Cr, 58Co, 65Zn, 110mAg, 115mCd, 203Hg*

Author:

Skog, E.; Wahlberg, J.E.

Year:

1964

Bibliographic source:

J. Invest. Derm. 43, 187-192

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

This study investigated the absorption of radioactive silver nitrate through the skin of the living guinea pig by following the disappearance of the radioactivity compounds from the cutaneous surface, so called "disappearance measurements".

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Silver nitrate

EC Number:

231-853-9

EC Name:

Silver nitrate

Cas Number:

7761-88-8

Molecular formula:

AgNO3

IUPAC Name:

Silver nitrate

Test material form:

solid

Specific details on test material used for the study:

Silver nitrate were obtained from J.T. Baker's Chemical Co (USA) 110m Ag, half-life 253 days.

Radiolabelling:

yes

Remarks:

110mAg (Half-life = 253 days)

Test animals

Species:

guinea pig

Strain:

not specified

Sex:

male/female

Details on test animals or test system and environmental conditions:

weight 300-500 g

Administration / exposure

Type of coverage:

not specified

Vehicle:

water

Remarks:

distilled water

Duration of exposure:

5 hours

Doses:

The concentrations were chosen which permitted direct comparison with previous investigations.
The lowest concentration was chosen on account of the specific activity of the perspective isotope.
The highest concentration was chosen by limiting solubility in distilled water at room temperature

No. of animals per group:

10-15 animals/dose

Results and discussion

Total recovery:

The absorption of silver nitrate is relatively small, most of the value given are <1.0% after 5 hours.

Any other information on results incl. tables

Disappearance constant (k) and disappearance percentage during 5 hours for silver nitrate for different concentration
k.10^5 min-1			< 3.4	3.4-6.6	6.7 -10.1	10.2-13.3
%/ 5 hours			< 1.0	1.0-1.9	2.0-2.9	3.0-3.9
Conc. M	pH	No.	No.	No.	No.	No.
0.00048	6.0	10	9	-	1	-
0.005	5.7	10	6	1	2	1
0.080	5.5	15	9	4	2	-
0.118	5.2	10	9	-	1	-
0.239	4.7	14	12	2	-	-
0.398	4.6	10	8	2	-	-
0.753	4.4	11	8	3	-	-
4.870	3.3	10	10	-	-	-

Disappearance constants and the disappearance percentage per 5-hours periods for silver nitrate for various concentration is presented in the table above.

 

Applicant's summary and conclusion

Conclusions:

Less than 1 % of an applied dose of silver nitrate was absorbed across intact skin of
guinea pigs within 5 hours of exposure. Test system not according to current standards
(i.e., no mass balance, no analysis of actual percutaneous transfer or residual Ag in skin
layers).