Sodium naphthalene-2-sulphonate

Basic toxicokinetics

Administrative data

Endpoint:

basic toxicokinetics in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Data source

Reference

Reference Type:

publication

Title:

Final Report on the Amended Safety Assessment of Sodium Polynaphthalenesulfonate and Sodium Naphthalenesulfonate1

Author:

Cytotest Cell Research GmbH & Co

Year:

2003

Bibliographic source:

International Journal of Toxicology, 22(Suppl. 2):37–44, 2003

Materials and methods

Objective of study:

absorption

Principles of method if other than guideline:

In Vitro Absorption study of 2-naphthalenesulfonic acid on pig skin

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Sodium naphthalene-2-sulphonate

EC Number:

208-523-8

EC Name:

Sodium naphthalene-2-sulphonate

Cas Number:

532-02-5

Molecular formula:

C10H8O3S.Na

IUPAC Name:

sodium naphthalene-2-sulphonate

Constituent 2

Reference substance name:

2-naphthalenesulfonic acid

IUPAC Name:

2-naphthalenesulfonic acid

Details on test material:

- Name of test material (as cited in study report): 2-naphthalenesulfonic acid (SNS)
- Molecular formula (if other than submission substance): C10-H8-O3-S.Na
C10-H7-O3-S.Na
- Molecular weight (if other than submission substance): 230.2183 g/mole
- Substance type: Organic
- Physical state: No data available
- Impurities (identity and concentrations): Not more than 0.5% sulfate (as sodium sulfate); not more than 20 mg/kg of heavy metals; and not more than 2 mg/kg arsenic.

Radiolabelling:

no

Test animals

Species:

pig

Strain:

not specified

Sex:

not specified

Administration / exposure

Route of administration:

other: Diffusion of porcine skin

Vehicle:

other: Physiologic saline (0.9% NaCl solution)

Details on exposure:

The skin was mounted in each of four glass diffusion chambers with a total surface area exposed of 1.13 cm2. Receptor chambers were filled with 7ml of physiologic saline (0.9% NaCl solution) and 339 μl of SNS (at a concentration of 1 μg/μl in deionized water) was placed in donor chambers. Each donor chamber was covered with parafilm and the diffusion chambers placed in an incubator at 37◦C. Samples (0.5 ml) were drawn from the receptor chamber at regular intervals. After the sample was taken, 0.5 ml of deionized water was added to each receptor chamber to keep volume constant.

Duration and frequency of treatment / exposure:

Single

Doses / concentrations

Remarks:

Doses / Concentrations:
339 μl

No. of animals per sex per dose / concentration:

1

Control animals:

yes, concurrent vehicle

Positive control reference chemical:

Data not available

Details on study design:

Samples were analyzed by measuring the amount of UV absorbed at 227 nm. The experiment was replicated once.

Details on dosing and sampling:

Data not available

Statistics:

Data not available

Results and discussion

Preliminary studies:

Data not available

Main ADME results

Type:

absorption

Results:

Small amounts were absorted from pig skin

Toxicokinetic / pharmacokinetic studies

Details on absorption:

Small amounts of SNS were lost from the donor fluid by penetration through or absorption into porcine skin. Of the 339 μg applied, only around 5 μg was noncovalently bound to the skin and only approximately 1% of the applied material appeared in the receptor fluid.

Details on distribution in tissues:

Data not available

Details on excretion:

Data not available

Metabolite characterisation studies

Metabolites identified:

not specified

Details on metabolites:

Data not available

Bioaccessibility (or Bioavailability)

Bioaccessibility (or Bioavailability) testing results:

Data not available

Any other information on results incl. tables

Concentration (μg/ml) of Sodium Naphthalenesulfonate appearing in receptor chambers as a function of time (Cytotest Cell Research GmbH & Co. 1997)

	Experiment 1				Experiment 2
Time (hours)	Chamber 1	Chamber 2	Chamber 3	Chamber 4	Chamber 1	Chamber 2	Chamber 3	Chamber 4
0	0.00	0.08	0.05	0.01	0.09	0.13	0.10	0.10
0.5	0.13	0.14	0.14	0.08	0.14	0.09	0.09	0.14
1.0	0.14	0.17	0.16	0.09	0.17	0.13	0.14	0.19
2.0	0.24	0.25	0.28	0.22	0.22	0.17	0.25	0.25
4.0	0.24	0.28	0.28	0.18	0.31	0.27	0.39	0.33
6.0	0.34	0.42	0.37	0.29	0.38	0.34	0.50	0.36
8.0	0.31	0.49	0.41	0.33	0.38	0.32	0.55	0.35
24.0	0.51	0.53	0.52	0.62	0.49	0.44	0.75	0.58

 

Sodium Naphthalenesulfonate concentration in donor fluid (μg/ml) and the amount (μg) eluted from skin patches at the end of the experiment (Cytotest Cell Research GmbH & Co. 1997)

	Experiment 1		Experiment 2
Chamber	Concentration in donor fluid∗	Amount eluted from skin	Concentration in donor fluid∗	Amount eluted from skin
1	947.13	4.74	996.51	5.99
2	985.04	5.59	1003.49	5.69
3	995.51	5.19	1000.00	4.99
4	929.18	5.39	992.02	4.89

^∗Sodium Naphthalenesulfonate was applied at a concentration of 1 μg/μl in a 339-μl aliquot.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): low bioaccumulation potential based on study results
On the basis of observed result it is concluded the 2-naphthalenesulfonic acid have very low absorption and expected to have Low bio-accumulation potential based on study results.

Executive summary:

In a in vitroAbsorption study, porcine skin of pig weremounted in diffusion chambers with a total surface area exposed of 1.13 cm2. Receptor chambers were filled with 7ml of physiologic saline (0.9% NaCl solution) and 339 μl of SNS (at a concentration of 1 μg/μl in deionized water) was placed in donor chambers. After 24 h, Skin patches were removed and eluted with 2 ml of deionized water, centrifuged

and the concentration of SNS in the supernatantwas determined. small amounts of SNS were lost from the donor fluid by penetration through or absorption into porcine skin. Of the 339 μg applied, only around 5 μg was noncovalently bound to the skin and only approximately 1% of the applied material appeared in the receptor fluid.Therefore, on the basis of observed result it is concluded the2-naphthalenesulfonic acidhavevery low absorptionandexpected to have Low bio-accumulation potential based on study results.