Esterification product of sunflower-oil fatty acids, with 1,4:3,6-dianhydro-D-glucitol

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 25 October 2018 to 21 December 2018

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Due to the strongly hydrophobic behaviour of test item and despite the efforts made to improve the sensitivity of the analytical method, an accurate value of the water solubility could not be provided. However the results show that the water solubility is < 1 mg/L.

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

Adopted 27 July 1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Version / remarks:

Regulation (EC) No 440/2008 of 30 May 2008

Deviations:

no

Principles of method if other than guideline:

Due to the expected low solubility of the test item, a concentration step by liquid-liquid extraction was applied during the validation of the analytical method, which needs relatively high sample volumes and which is not practicable in the column elution method. Hence in this case the flask method was applied.

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Key result

Water solubility:

1 mg/L

Conc. based on:

test mat. (dissolved fraction)

Loading of aqueous phase:

0.44 other: mg/ml

Incubation duration:

>= 48 - <= 72 h

Temp.:

20 °C

pH:

>= 5.92 - <= 6.11

Remarks on result:

other: Not determined accurately due to the strongly hydrophobic behaviour of test item. The water solubility is less than 1 mg/L.

Details on results:

After one-day saturation time, the test item was not detectable after enrichment (or <The two-day and three-day saturation time, results were similar, and the deviation from the measured daily mean concentration was less than 15% (11.8%).
The high relative standard deviations of the parallel extractions from each tubes show that extraction of the test item from the ultrapure water was not highly reproducible. This suggests the presence of some inhomogeneous microemulsion of the test item or colloid particles, which probably can pass through the filter. It is considered that the real water solubility is probably significantly lower than the experimentally determined values.

Parallel tubes	Parallel extraction	Measured concentration after 1 day (mg/L)	pH	Measured concentration after 2 days (mg/L)	pH	Measured concentration after 3 days (mg/L)	pH	Solubility of the test item (mg/L)
1	1	nd	5.82	0.63	6.01	0.71	6.04
	2	nd		0.87		0.57
	3	bql		1.33		0.72
	Mean	bql	-	0.94	-	0.66	-
	RSD %	-		37.8%		12.8%
2	1	bql	6.02	0.56	6.11	1.24	5.99
	2	bql		0.44*		1.09
	3	bql		0.51		1.57
	Mean	bql	-	0.51	-	1.30	-
	RSD %	-		12.2%		19.0%
3	1	nd	6.07	0.49*	6.08	0.58	6.02
	2	bql		0.53		0.59
	3	nd		0.51		0.61
	Mean	bql	-	0.51	-	0.59	-
	RSD %	-		4.2%		3.1%
Mean	mg/L	bql	-	0.65	-	0.85	-	0.75
RSD %	%	-		38.4%		45.4%		11.8%

nd= not detected

bql= below the quantification limit (less than LOQ)

*Although these values are slightly below the quantification limit, these are included in the calculation, because these results are similarly representative for the behaviour of the test item.

 

Conclusions:

The water solubility of the substance "Esterification products of 1,4:3,6-dianhydro-D-glucitol with sunflower oil fatty acids" is less than 1 mg/L at 20°C and pH around 6.

Executive summary:

The water solubility of the substance " Esterification products of 1,4:3,6-dianhydro-D-glucitol with sunflower oil fatty acids" was determined according to the EU method A.6 and the OECD 105 and in compliance with the GLP.

Due to the expected low solubility of the test item, a concentration step by liquid-liquid extraction was applied during the validation of the analytical method, which needs relatively high sample volumes and which is not practicable in the column elution method. Hence in this case the flask method was applied.

Oversaturated solutions (20 mg in 45 ml ultra pure water) were prepared in tubes (3 parallel tubes on each day and the control tubes). The tubes were shaken vigorously at about 30°C for 1, 2 and 3 days. Then the tubes were removed and re-equilibrated at 20 ± 1°C for 24 hours. After the re-equilibration time, the content of the vessels was filtered by 0.22 µm filter. The samples were concentrated to 10 fold by liquid-liquid extraction (3 parrallel extraction from each tube, except the control tubes which were extracted with one sample) and the concentration of the test item in the solvent extract samples was determined by the validated GC-FID method (17/310-316AN). Then the concentration in the water was back-calculated.

After one-day saturation time, the test item was not detected and after 2 -day and 3-day saturation time, the deviation from the measured daily mean concentration was less than 15% and the results are considered as similar.

However the high relative standard deviation of the parallel extractions show that extraction of the test item from the ultrapure water was not highly reproducible. This suggests the presence of some inhomogeneous microemulsion of the test item or colloid particles, which probably can pass through the filter. Therefore accurate value of the water solubility can not be determined and it is considered that the real water solubility is probably significantly lower than the experimentally determined values.

In conclusion, the water solubility of LAB 4448 was determined to be less than 1 mg/L at 20°C ± 0.5°C using the shake-flask method.

The water solubility study is classified as acceptable taking into account the low solubility of the test item and the efforts made to improve the sensitivity of the analytical method.

Description of key information

The water solubility of the substance "Esterification products of 1,4:3,6-dianhydro-D-glucitol with sunflower oil fatty acids" is less than 1 mg/L at 20°C and pH around 6.

Key value for chemical safety assessment

Water solubility:

1 mg/L

at the temperature of:

20 °C

Additional information

The water solubility of the substance " Esterification products of 1,4:3,6-dianhydro-D-glucitol with sunflower oil fatty acids" was determined according to the EU method A.6 and the OECD 105 and in compliance with the GLP.

Due to the expected low solubility of the test item, a concentration step by liquid-liquid extraction was applied during the validation of the analytical method, which needs relatively high sample volumes and which is not practicable in the column elution method. Hence in this case the flask method was applied.

Oversaturated solutions (20 mg in 45 ml ultra pure water) were prepared in tubes (3 parallel tubes on each day and the control tubes). The tubes were shaken vigorously at about 30°C for 1, 2 and 3 days. Then the tubes were removed and re-equilibrated at 20 ± 1°C for 24 hours. After the re-equilibration time, the content of the vessels was filtered by 0.22 µm filter. The samples were concentrated to 10 fold by liquid-liquid extraction (3 parrallel extraction from each tube, except the control tubes which were extracted with one sample) and the concentration of the test item in the solvent extract samples was determined by the validated GC-FID method (17/310-316AN). Then the concentration in the water was back-calculated.

After one-day saturation time, the test item was not detected and after 2 -day and 3-day saturation time, the deviation from the measured daily mean concentration was less than 15% and the results are considered as similar.

However the high relative standard deviation of the parallel extractions show that extraction of the test item from the ultrapure water was not highly reproducible. This suggests the presence of some inhomogeneous microemulsion of the test item or colloid particles, which probably can pass through the filter. Therefore accurate value of the water solubility can not be determined and it is considered that the real water solubility is probably significantly lower than the experimentally determined values.

In conclusion, the water solubility of LAB 4448 was determined to be less than 1 mg/L at 20°C ± 0.5°C using the shake-flask method.