Dl-Proline, 5-oxo-, compd. with N2-coco acyl-l-arginine Et ester

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14 August 2017 to 17 November 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:

65 600 mg/L

Conc. based on:

test mat.

Incubation duration:

3 d

Temp.:

20 °C

pH:

5

Remarks on result:

other: 65.6 ± 1.43 mg/mL

Details on results:

- pH of the samples varied in the range of 4.94 – 5.00.
- The concentration in the clear solvent phase of samples were analysed with the HPLC method. Measured concentrations are summarised in Table 2.
- From the highest visually acceptable solution, the concentration was determined to be 65.6 ± 1.43 mg/mL (95 % confidence interval) at 20 ± 0.5 °C using the shake-flask method.

Table 1: Preliminary test of the different ratio of mixtures by visual assessment

How many times excess of the estim. solubility	Amount of		Visual Observations
	Test Material (g)	Water (mL)	Shaking	Re-equilibration	For further analysis
			at 30 °C	at 20 °C
1x	1.75	25	apparently a colourless solution	slight crystallisation	filterable, solution-like
2x	3.50	25	apparently a white, viscous suspension	cream-like suspension	untreatable
3x	5.25	25	apparently a white, viscous suspension	cream-like suspension	untreatable
4x	7.00	25	apparently a white, viscous suspension	cream-like suspension	untreatable

Table 2: Results of the determination of the test material concentrations

Measured concentration after 1 day (mg/mL)	pH	Measured concentration after 2 days (mg/mL)	pH	Measured concentration after 3 days (mg/mL)	pH	Concentration of the test material* (mg/mL)
64.9	5.00	62.5	4.96	64.8	5.00	65.6 ± 1.43
64.6	4.98	65.1	4.96	65.5	4.94
68.1	4.96	66.3	4.95	68.5	4.96
Mean: 65.9	-	Mean: 64.6	-	Mean: 66.3	-	RSD% = 2.8 %

* From a solution made at the maximum visual concentration as a solution, at 1.75 g test material per 25 mL.

Conclusions:

Under the conditions of this study, the water solubility of the test material was determined to be 65.6 ± 1.43 mg/mL (95 % confidence interval) at 20 ± 0.5 °C.

Executive summary:

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

The test material: water ratio used for the main test was determined in a preliminary visual assessment. About 1.75 g of test material was measured into stoppered Erlenmeyer flasks (three parallel). After the addition of 25 mL ultrapure water, the flasks were agitated at 30 °C. After one and two days, three other similarly prepared flasks were agitated at 30 °C. One day later all of the vessels were removed and re-equilibrated at 20 °C for 24 hours. The samples were filtered, then diluted before the analysis (two parallel dilutions and two injections each). The concentration of the samples was determined by HPLC.

Under the conditions of this study, the water solubility of the test material was determined to be 65.6 ± 1.43 mg/mL (95 % confidence interval) at 20 ± 0.5 °C.

Description of key information

Under the conditions of this study, the water solubility of the test material was determined to be 65.6 ± 1.43 mg/mL (95 % confidence interval) at 20 ± 0.5 °C.

Key value for chemical safety assessment

Water solubility:

65 600 mg/L

at the temperature of:

20 °C

Additional information

The water solubility of the test material was investigated 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).

The test material: water ratio used for the main test was determined in a preliminary visual assessment. About 1.75 g of test material was measured into stoppered Erlenmeyer flasks (three parallel). After the addition of 25 mL ultrapure water, the flasks were agitated at 30 °C. After one and two days, three other similarly prepared flasks were agitated at 30 °C. One day later all of the vessels were removed and re-equilibrated at 20 °C for 24 hours. The samples were filtered, then diluted before the analysis (two parallel dilutions and two injections each). The concentration of the samples was determined by HPLC.

Under the conditions of this study, the water solubility of the test material was determined to be 65.6 ± 1.43 mg/mL (95 % confidence interval) at 20 ± 0.5 °C.