Reaction mass of L-Glutamic acid, N-coco acyl derivs., monosodium salts and sodium hydrogen N-(1-oxooctadecyl)-L-glutamate

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

12 June 2017 to 26 June 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Version / remarks:

2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Key result

Water solubility:

5 050 mg/L

Conc. based on:

test mat.

Incubation duration:

6 d

Temp.:

20 °C

pH:

>= 6.24 - <= 6.26

Remarks on result:

other: ± 0.104 mg/mL (95 % confidence interval)

Details on results:

CALIBRATION
- Six concentration levels were used: 1, 2, 5, 20, 50 and 100 μg/mL. The calibration graph was calculated applying quadratic regression using 1/concentration as weighting factor.

RESULTS OF THE SHAKE FLASK METHOD
- pH of the samples varied in the range of 6.24 to 6.26.
- Samples were analysed with the LC-MS method.
- Based on the measured concentrations the test mixtures were homogeneous.
- Based on the measured concentrations the saturation reached after three days. In the summary calculation the day four, five and six results were used.

Results of the determination of test material concentrations

Saturation time	Measured concentration (mg/mL)	pH	Mean concentration (mg/mL)
2 days	4.31	6.25	4.51
	4.60	6.25
	4.63	6.26
3 days	4.66	6.25	4.78
	4.77	6.26
	4.92	6.26
4 days	4.95	6.25	4.92
	4.87	6.24
	4.93	6.25
5 days	5.30	6.25	5.11
	4.96	6.25
	5.06	6.25
6 days	5.08	6.25	5.12
	5.16	6.26
	5.12	6.26
Solubility of the test material (mg/mL)			5.05 ± 0.104
RSD %			3 %

Summary of the standard curve parameters

C: -1.69 x 10^6

B: 2.20 x 10^6

A^2: 8.66 x 10^3

Correlation coefficient: 0.998

Conclusions:

Under the conditions of this study, the water solubility of the test material was determined to be 5.05 ± 0.104 mg/mL (95 % confidence interval) at 20 °C ± 0.5°C using the shake-flask method.

Executive summary:

The water solubility of the test material was determined in accordance with the standardised guidelines OECD 105 and EU Method A.6 under GLP conditions.

Water solubility was investigated using the shake-flask method. The test material was dissolved in water at a temperature somewhat above the test temperature. Then saturation is achieved the mixture is cooled and kept at the test temperature, as long as necessary to reach equilibrium. Subsequently, the mass concentration of the test material in the aqueous solution was determined by analytical methods. Before the LC-MS analysis the samples were diluted with methanol.

At first the test was performed with one, two and three days saturation time. The result showed that three days was not enough to reach the saturation. Therefore, the test was repeated with longer saturation time (6 days).

Under the conditions of this study, the water solubility of the test material was determined to be 5.05 ± 0.104 mg/mL (95 % confidence interval) at 20 °C ± 0.5°C using the shake-flask method.

Description of key information

Under the conditions of this study, the water solubility of the test material was determined to be 5.05 ± 0.104 mg/mL (95 % confidence interval) at 20 °C ± 0.5°C using the shake-flask method.

Key value for chemical safety assessment

Water solubility:

5.05 g/L

at the temperature of:

20 °C

Additional information

The water solubility of the test material was determined in accordance with the standardised guidelines OECD 105 and EU Method A.6 under GLP conditions. The study was awarded a reliability score of 1 in accordance with the criteria set forth by Klimisch et al. (1997).

Water solubility was investigated using the shake-flask method. The test material was dissolved in water at a temperature somewhat above the test temperature. Then saturation is achieved the mixture is cooled and kept at the test temperature, as long as necessary to reach equilibrium. Subsequently, the mass concentration of the test material in the aqueous solution was determined by analytical methods. Before the LC-MS analysis the samples were diluted with methanol.

At first the test was performed with one, two and three days saturation time. The result showed that three days was not enough to reach the saturation. Therefore, the test was repeated with longer saturation time (6 days).

Under the conditions of this study, the water solubility of the test material was determined to be 5.05 ± 0.104 mg/mL (95% confidence interval) at 20 °C ± 0.5°C using the shake-flask method.