Acetylcysteine

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2018-02-28 to 2018-09-17

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7840 (Water Solubility)

Deviations:

no

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:

179.5 g/L

Conc. based on:

test mat.

Temp.:

20 °C

pH:

2.7

Preliminary Test

The preliminary test at room temperature showed, that the water solubility of the test item was between 62.9 g/L and 167.6 g/L.

 

Preliminary test for the water solubility

Amount of test item [mg]	Total volume of added water [mL]	Ultrasonic bath [min]	Remark
100.56	0.1	--	not dissolved
	0.6	--	not dissolved
	1.6	2	dissolved

The solubility of the test item in water at room temperature was estimated to be > 62.9 g/L and < 167.6 g/L. Therefore, the flask method was performed.

 

Main Test

For the main test three flasks were prepared with an amount of test item and water, and one flask only with water. After stirring and centrifugation the aqueous phases were measured by means of HPLC. The solution of each flask has been measured twice. The values represented in the table are rounded values. The calculation was carried out with the original not rounded values.

Results of the flask method

 

Flask	1a	2a	3a	4a
measured value [mg/L]	161.9 / 166.6	201.5 / 201. 5	171.7 / 174.0	0 / 0
aliquot of the flask [mL]	1	1	1	1
total volume after 1^stdilution [mL]	100	100	100	100
aliquot of the 1^stdilution [mL]	0.1	0.1	0.1	0.1
total volume after 2^nddilution [mL]	1	1	1	1
water solubility [g/L]	161.9 / 166.6	201.5 / 201. 5	171.7 / 174.0	0 / 0
average water solubility [g/L]	164.2	201.5	172.9	0
mean value of the water solubility [g/L]	179.5			0
standard deviation [g/L]	19.5			--
relative standard deviation [%]	10.9			--

 

Conclusions:

The water solubility was determined to be 179.5 ± 10.9 g/L.

Executive summary:

The water solubility was determined according to OECD 105 using the shake flask method with HPLC analysis. In a preliminary test, in a stepwise procedure, increasing volumes of water were added at room temperature to approximately 0.1 g of the test item in a 100 mL glass-stoppered measuring cylinder. The water solubility was estimated to be between 62.9 and 167.6 g/L. In the main test, amounts of the test item were weighed into each of three flasks. After addition of 100 mL of double distilled water to each flask the flasks were stirred at 30 °C for different periods of time (24, 48 and 72 h). After the stirring times enough precipitate remained in the flasks to ensure the saturation of the solution. After stirring at 30 °C the flasks were cooled down to 20 °C and stirred at 20 °C for another 24 h. After 24 h stirring time the contents of the flasks were centrifuged for 30 min at 20 °C with 15000 rpm. For the analytical measurement by means of HPLC the centrifuged clear aqueous phases were diluted from 1 mL to 100 mL and again from 0.1 mL to 1 mL with double distilled water. The water solubility at 20 °C of the test item was determined to be 179.5 ± 10.9 g/L.

Description of key information

The water solubility was determined to be 179.5 ± 10.9 g/L.

Key value for chemical safety assessment

Water solubility:

179.5 g/L

at the temperature of:

20 °C

Additional information

The water solubility was determined according to OECD 105 using the shake flask method with HPLC analysis. In a preliminary test, in a stepwise procedure, increasing volumes of water were added at room temperature to approximately 0.1 g of the test item in a 100 mL glass-stoppered measuring cylinder. The water solubility was estimated to be between 62.9 and 167.6 g/L. In the main test, amounts of the test item were weighed into each of three flasks. After addition of 100 mL of double distilled water to each flask the flasks were stirred at 30 °C for different periods of time (24, 48 and 72 h). After the stirring times enough precipitate remained in the flasks to ensure the saturation of the solution. After stirring at 30 °C the flasks were cooled down to 20 °C and stirred at 20 °C for another 24 h. After 24 h stirring time the contents of the flasks were centrifuged for 30 min at 20 °C with 15000 rpm. For the analytical measurement by means of HPLC the centrifuged clear aqueous phases were diluted from 1 mL to 100 mL and again from 0.1 mL to 1 mL with double distilled water. The water solubility at 20 °C of the test item was determined to be 179.5 ± 10.9 g/L (reference 4.8 -1)