Registration Dossier

Administrative data

Endpoint:
water solubility
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Jan 19 - Mar 23 2018
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018
Report Date:
2018

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 105 (Water Solubility)
Version / remarks:
July 27, 1995
GLP compliance:
yes
Type of method:
flask method

Test material

Reference
Name:
Unnamed
Type:
Constituent

Results and discussion

Water solubility
Water solubility:
>= 1.49 - <= 2.25 mg/L
Temp.:
20 °C
pH:
>= 6 - <= 6.5

Any other information on results incl. tables

Test results

Sample

pH

Concentration of test item in test solution (mg/L)

Average (mg/L)

Standard deviation

Maximum difference (%)

Sample 1-a

6.5

1.49

 

 

 

Sample 1-b

6.2

1.65

 

 

 

Sample 2-a

6.5

2.15

 

 

 

Sample 2-b

6.0

1.75

 

 

 

Sample 3-a

6.3

1.63

 

 

 

Sample 3-b

6.1

2.25

1.82

0.307

33.7

 

Water solubility: 1.49 - 2.25 mg/L (20 °C)

 

 

Discussion

Recovery test

In the OECD Guidelines for Testing of Chemicals, No. 105 (TG105), the centrifugation is recommended as a means to separate the insoluble substance from the test solution. However, the insoluble part of test item could not be separated by the centrifugation (1000xg to 10000xg, 20 min.) from the cloudy solution because the test item is liquid and its specific gravity is close to that of water. Therefore, the insoluble part of test item in the test solution was filtered with a membrane filter. The filtrate was transparent and checked that the colloidal matter did not exist by the examination of the Tyndall effect. From the above-mentioned results, the insoluble part of test item and the solution were able to be separated by filtration. The recovery rate of test item by the filtration was low but adopted as the correction coefficient of the test item concentration in the test solution because the repeatability of recovery rates was good.

 

Variation of water solubility

The variation among the test item concentrations in the test solutions was more than 15%, the variation criteria in the TG105. It was considered that the large variation was caused by the difficulty of complete separation between the insoluble part of test item and the solution. However, the test item concentrations in the test solutions did not show an increasing tendency. Therefore, the range of measurement results was adopted as the water solubility of test item.

Applicant's summary and conclusion