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Administrative data

specific investigations: other studies
Type of information:
experimental study
Adequacy of study:
supporting study
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions
Most of it performed under GLP, well documented. Analytical method not sensitive enough.

Data source

Reference Type:
study report
Report date:

Materials and methods

Test guideline
according to guideline
other: "Practical Guidelines for Mutagenicity and Hydrolysis Data requested by SCF". Appendix 2: "Hydrolysis data" Issued by The Commission of the European Communities.
GLP compliance:
yes (incl. QA statement)
Type of method:
in vitro

Test material

Constituent 1
Chemical structure
Reference substance name:
Dioctadecyl 3,3'-thiodipropionate
EC Number:
EC Name:
Dioctadecyl 3,3'-thiodipropionate
Cas Number:
Molecular formula:
dioctadecyl 3,3'-thiodipropionate
Details on test material:

Administration / exposure

unchanged (no vehicle)
Details on exposure:
Medium 1 : Simulated gastric fluid (pH 1.2)
Medium 2 : Simulated intestinal fluid (pH 7.5)
Medium 3 : Simulated saliva (pH 9.0)

1.1. Simulated gastric fluid (Medium 1)
700 ml of hydrochloric acid are diluted to 1000 ml with distilled water. The resulting pH value is 1.19.

1.2. Simulated intestinal fluid (Medium 2)
6.8 g of KH2PO4 are dissolved in 250 ml of water, 190 ml of 0.2 N NaOH and 400 ml of water are added. 10.0 g of pancreatin (Fluka, pig pancreas) are added, mixed, and the pH is adjusted to a value of 7.50 with 42 ml of 0.2 N NaOH. This solution is diluted with water to 1000 ml.

1.3. Simulated saliva (Medium 3)
4.2 g of sodium bicarbonate (NaHC03), 0.5 g of sodium chloride (NaCl) and 0.72 g of potassium carbonate (K2CO3) are dissolved in 1 liter of distilled water. The resulting solution has a pH value of 9.0.
Analytical verification of doses or concentrations:
Details on analytical verification of doses or concentrations:
The test solutions are analysed by liquid chromatography.
Pareuneters are given below:
Injector : SPECTRA-PHYSICS 8780 XR
Injection vol. : 10 y.1
Column : steel, 125 x 4,6 mm, packed with NUCLEOSIL C-18 5 micrometer
Column temp. : room temperature
Mobile phase :acetonitrile/tetrahydrofuran (70 + 30 parts by volume)
Flow : 1 ml/min
Detection wavelength 205 nm
Retention time: approx 7.4 min
Detection limit: 20 mg/L
Duration of treatment / exposure:
In each case 2.00 - 2.50 mg of Irganox PS 802 are weighed into a 25 ml round bottom flask. 10 ml of the respective media (heated up to 37°C) are added. The test mixtures are kept at 37°C with stirring for at the most 240 min. The mixtures then quantitatively are transferred to 50 ml volumetric flasks using tetrahydrofuran and adjusted to the mark with tetrahydrofuran. The resulting solutions are analysed by liquid chromatography.

Results and discussion

Details on results:
The solubilities of the test substance in all media tested are below the detection limit of the analytical method. Therefore the hydrolysis test could not be performed. Still it was shown that the substance was stable to at least 90% of the initial concentration in all media tested (The stability tests were not performed according to GLP).

Applicant's summary and conclusion