Registration Dossier

Diss Factsheets

Physical & Chemical properties

Water solubility

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
water solubility
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2008.04.01-2008.04.11
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP-Guideline study
Qualifier:
according to guideline
Guideline:
EU Method A.6 (Water Solubility)
Qualifier:
according to guideline
Guideline:
OECD Guideline 105 (Water Solubility)
GLP compliance:
yes (incl. QA statement)
Remarks:
The Department of Health of the Government of the United Kingdom
Type of method:
flask method
Water solubility:
ca. 3.68 mg/L
Temp.:
20 °C
pH:
ca. 7.3
Water solubility:
ca. 3.89 mg/L
Temp.:
20 °C
pH:
ca. 7.6
Water solubility:
ca. 3.51 mg/L
Temp.:
20 °C
pH:
ca. 7.8
Details on results:
To remove dissolved oxygen from the glass double-distilled water, to reduce the effects of oxidation of the test material, a volume was boiled and sparged with nitrogen and stored in a closed vessel with a nitrogen headspace. The prepared samples were sealed with a nitrogen purged headspace for shaking at 30 °C and equilibration at 20 °C.

As the Sponsor indicated the test material hydrolysed in water, it was decided to carry out the test with reduced shaking/equilibration times. This would then reduce the extent of hydrolysis occurring and also oxidation. Therefore, the solution would contain less hydrolysis products, which often being more water soluble than the test material, would possibly act as a co-solvent in helping to dissolve more test material than would otherwise occur.

The ion masses were chosen for the analysis to monitor the ions with different adducts and to give a representative profile of the test material. The peak at 6 minutes represents the main component of the test material and the one used to calculate the water solubility value. The other 2 main peaks at 3 and 8.5 minutes are the tri-ester and penta-ester impurities respectively.

The estimated water solubility using WSKOW v1.41, © 2000 US Environmental Protection Agency was calculated at 5.224 mg/l at 25 °C. Using a partition coefficient of 3.03 in the calculations, as determined in Safepharm Project 1158/0056, amended the value to 2.188 mg/l at 25 °C.

Concluding, triplicate experimental determinations resulted in the following concentrations of test material in water solution: 3.68 mg/L (pH~7.3), 3.89 mg/L (pH~7.6) and 3.51 mg/L (pH~7.8), mean concentration was reported 3.69 mg/L at 20.0+/-0.5 °C and range of concentrations: 3.51 mg/L to 3.89 mg/L.
The water solubility of the test material has been determined to be 3.69 mg/l of solution at 20.0+/-0.5 °C.

The prelimianry test of water solubility waas 6.71 mg/l.

The mean peak areas relating to the standard and sample solutions are shown in the following table (Table 1):

Table 1:

 solution  mean peak area
standard 0.274 mg/l  1.680x106 
standard 0.292 mg/l 1.971x106 
 blank none detected  
 sample 1A 2.385x105 
 sample 1B 2.355x105
 sample 2A 2.520x105
 sample 2B 2.489x105
 sample 3A 1.666x105 (not used in calculations due to inconsistency)
 sample 3B 2.260x105

The concentration (g/l) of the test material in the sample solutions is shown in the following table (Table 2):

Table 2:

 sample number  time shaken at ~ 30 °C (hours)  time equilibrated at 20 °C (hours) concentration (g/l)  solution pH
1  1  1 3.68x10-3 7.3
2  2  1 3.89x10-3 7.6
 3  1 3.51x10-3 7.8

Mean concentration: 3.69x10 -3 g/l at 20 +/-0.5 °C.

Range: 3.51x10-3to 3.89x10-3g/l.

Conclusions:
Interpretation of results: slightly soluble (0.1-100 mg/L)
The water solubility of the test material THIOCURE PETMP has been determined to be ~3.69 mg/l of solution at 20.0+/-0.5°C and pH~7.57.
Executive summary:

The test material THIOCURE PETMP has been determined to have a water solubility ~3.69 mg/l of solution at 20.0 +/-0.05 °C (at pH~7.57) by using flask method with concentration determination by high performance liquid chromatography – mass spectrometry (HPLC-MS), according to method 105 OECD Guideline for Testing of Chemicals, 27 July 1995 and Method A6 of Commission Directive 92/69/EEC (which constitutes Annex V of Council Directive 67/548/EEC).

Description of key information

Water solubility: ~3.69 mg/l of solution at 20.0 +/-0.05 °C (at pH~7.57)
Fox, J.M. (2008)

Key value for chemical safety assessment

Water solubility:
3.69 mg/L
at the temperature of:
20 °C

Additional information

In the experimental laboratory study the water solubility of the test substance THIOCURE PETMP has been determined to be ~3.69 mg/l of solution at 20.0 +/-0.05 °C (at pH~7.57) by using flask method with concentration determination by high performance liquid chromatography – mass spectrometry (HPLC-MS), according to method 105 OECD Guideline for Testing of Chemicals, 27 July 1995 and Method A6 of Commission Directive 92/69/EEC (which constitutes Annex V of Council Directive 67/548/EEC).