Ethyl pyruvate

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

26 October 2017 - 09 March 2018

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Key result

Water solubility:

>= 65.1 - <= 69.4 other: w/w%

Conc. based on:

test mat.

Temp.:

20 °C

pH:

1.6

Details on results:

Based on the extremely high water solubility of the test item, it was not possible to prepare
sample solutions at five times the saturation concentration and isolate the resulting saturated
solution for analysis, as specified in the regulatory methods quoted in Section 4.5.1.

Therefore, a range of sample solution concentrations were prepared, using the standardized
preparation and treatment steps specified in these methods, and the solubility of the test item
determined by visual assessment.

Following completion of the Preliminary Test/Miscibility Test 1, further, unreported samples
were prepared to cover a nominal concentration range of 25 to 50% w/w. However on
shaking these samples for a saturation period of 72 hours, which is the standardized
maximum time applied by the regulatory methods, following re-equilibration to 20 °C for
24 hours, all samples were fully miscible/soluble with water. As a result of this, Miscibility
Test 2 was initiated, to further characterize the solubility properties of the test item under the
standardized sample treatment conditions of the regulatory methods. This, as suspected,
showed an increased solubility when compared to the first test performed, which used an
initial saturation period of only 21 hours.

Finally, the Main Test samples were prepared to narrow down the solubility range of the test
item to an approximately 5% w/w bracket, under identical, standardized sample preparation
and treatment conditions.

On review of the water solubility data generated, in particular the pH values obtained and the
test item structure, time dependent solubility characteristics observed were attributed to the
influence of hydrolysis of the test item. The low pH of all aqueous solutions, and a further
decrease for similar concentration solutions but with an extended preparation period,
supported hydrolysis of the ester functional group to generate the corresponding carboxylic
acid and alcohol, promoting solubility.

Conclusions:

The water solubility of the test item has been determined to be in the range 65.1 to 69.4% w/w of solution at 20.0 ± 0.5 °C.

Executive summary:

The water solubility of the test item has been determined to be in the range 65.1 to 69.4% w/w of solution at 20.0 ± 0.5 °C.

Description of key information

The water solubility of the test item has been determined to be in the range 65.1 to 69.4% w/w of solution at 20.0 ± 0.5 °C.