Butanedioic acid, 2-hydroxy-, 1,4-bis[5,7,7-trimethyl-2-(1,3,3-trimethylbutyl)octyl] ester

Hydrolysis

Administrative data

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

July 2007 - March 2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.7 (Degradation: Abiotic Degradation: Hydrolysis as a Function of pH)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

1,4-bis[2-(4,4-dimethylpentan-2-yl)-5,7,7-trimethyloctyl] 2-hydroxybutanedioate

EC Number:

807-422-1

Cas Number:

66918-01-2

Molecular formula:

C40H78O5

IUPAC Name:

1,4-bis[2-(4,4-dimethylpentan-2-yl)-5,7,7-trimethyloctyl] 2-hydroxybutanedioate

Details on test material:

- Name of test material (as cited in study report): SALACOS 222
- Physical state: liquid
- Analytical purity: > 98%
- Lot/batch No.: 7-2-D
- Expiration date of the lot/batch: 04/10
- Stability under test conditions: stable
- Storage condition of test material: room temperature (20 +/- 5 °C)

Specific details on test material used for the study:

Identification: SALACOS 222
Batch Number: 7-2-D
Purity: > 98%
Appearance: Liquid
Expiry Date: April 2010
Storage Conditions: At room temperature at about 20 °C
Molecular Weight: 639.065 g/mol
Preparation of the Test Solutions
About 23 mg of SALACOS 222 were dissolved in 2 mL solubilizer (acetone, ethanol and
tetrahydrofuran, respectively) and filled up to 100 mL with the respective buffer solution (pH 4.0,
pH 7.0 and pH 9.0). Each mixture was ultrasonified and submitted to a 0.2 μm filtration. To
obtain a test solution of not more than half the water solubility, 50 mL of the filtered solution
was diluted to 100 mL with the respective buffer. 5 mL of these solutions were evaporated to
dryness in a rotary evaporator. The residue was dissolved in 2 mL of tetrahydrofuran.
Aliquots of each test solution were measured using the analytical method as described later in
this report.

Radiolabelling:

no

Study design

Analytical monitoring:

yes

Details on sampling:

20 μL aliquots of each test solution at each pH value were analyzed without dilution

Buffers:

Buffer Solution pH 4.0
Biphthalate buffer, pH 4.00 ± 0.02 (25 °C), J.T. Baker, Art. No. 5657
Buffer Solution pH 7.0
Phosphate buffer, pH 7.00 ± 0.02 (25 °C), J.T. Baker, Art. No. 5656
Buffer Solution pH 9.0
Borate/Potassium chloride/NaOH buffer, pH 9.00 ± 0.02 (20 °C), J.T. Baker, Art. No. 7145
Rationale: The test system and test method are recommended by international guidelines.

HPLC-Conditions
Apparatus: Merck-Hitachi autosampler L-7200
Merck-Hitachi pump L-6200
Detector ELSD (Low Temperature Evaporative Light Scattering
Detector), Oven Temperature: 60 °C, Gain 7
Column: Mini Mixed E PLGEL; 250 x 4.6 mm; 3 μm
Eluent: Tetrahydrofuran
Temperature: Room temperature
Injection Volume: 20 μL
Flow: 0.5 mL/min
Run Time: 15 minutes
Retention Time
of SALACOS 222: Approx. 4.8 minutes under these HPLC-conditions

Estimation method (if used):

Model Calculation (QSAR) of the Partition Coefficient (n-Octanol /
Water) and the Water Solubility
For the determination of the hydrolysis behavior of a test item a suitable that means a sufficient
sensitive analytical method must be available. For SALACOS 222 this is not the case. Therefore
no main test could be performed as described in the guidelines and in accordance with the RCC
Ltd Standard Operating Procedures.
To give an idea oft the low water solubility the value was calculated using a model calculation as
given later in this report. For the calculation the partition coefficient (n-octanol/water) was used.

Calculation of the Partition Coefficient (n-Octanol / Water)
The log POW of the test item was estimated by a calculation method1 based on the theoretical
fragmentation of the molecule into substructures for which reliable log POW increments are
known. The log POW is obtained by summing the fragment values and the correction terms for
intramolecular interactions. Details of the fragmentation and the calculation are given in the
attached table. The estimated value was 15.4904.

Details on test conditions:

According to the guidelines, the following tests were performed.
The solubility of SALACOS 222 in the buffer solutions pH 4.0, pH 7.0 and pH 9.0 is very low,
therefore a test with different solubilizers was performed to increase the solubility of
SALACOS 222. Aliquots of each test solution were measured using the analytical method as
described later in this report.

Number of replicates:

not applicable (see any other information on materials and methods section)

Positive controls:

not specified

Negative controls:

not specified

Statistical methods:

none

Results and discussion

Preliminary study:

The solubility of SALACOS 222 in the buffer solutions pH 4.0, pH 7.0 and pH 9.0 was very low.
It was not possible to increase the solubility of the test item with the use of different solubilizers
(acetone, ethanol and tetrahydrofuran). Peaks obtained, if any, were too small to allow
quantification or even to follow a degradation curve. The calculation of the water solubility at
25 °C, based on the molecule structure of SALACOS 222 result in 1.7 · 10-11 mg/L.
According to the EEC Directive 92/69, Section C.7, the method is applicable only to water
soluble substances. The test item shows no significant solubility in the different solvent systems.
Therefore, no further testing could be performed with SALACOS 222 at pH 4.0, pH 7.0 and
pH 9.0. Additionally, no sensitive analytic method was available.
Therefore, no hydrolyze testing could be performed with SALACOS 222 at different pH values.

Transformation products:

not measured

Dissipation DT50 of parent compound

Key result

Remarks on result:

not determinable because of methodological limitations

Applicant's summary and conclusion

Validity criteria fulfilled:

not applicable

Conclusions:

The solubility of SALACOS 222 in the buffer solutions pH 4.0, pH 7.0 and pH 9.0 was too low
to allow quantification or even to follow a degradation curve. The test item shows no significant
solubility in the different solvent systems (acetone, ethanol and tetrahydrofuran). Therefore, no
further testing could be performed with SALACOS 222 at pH 4.0, pH 7.0 and pH 9.0.
Additionally, no sensitive analytic method was available.

Executive summary:

The solubility of SALACOS 222 in the buffer solution pH 4.0, pH 7.0 and pH 9.0 was very low.

It was not possible to increase the solubility of the test item with the use of a solubilizer (acetone,

ethanol and tetrahydrofuran). Peaks obtained, if any were too small to allow quantification or

even to follow degradation. Additionally, no sensitive analytic method was available.

According to the EEC Directive 92/69, Section C.7, the method is applicable only to water

soluble substances. The test item shows no significant solubility in the different solvent systems.

Therefore, no further testing could be performed with SALACOS 222 at pH 4.0, pH 7.0 and

pH 9.0.