Potassium (2S)-4-carboxy-2-(tetradecanoylamino)butanoate

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

06 May 2013 to 10 May 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Water solubility:

58.4 g/L

Temp.:

20 °C

pH:

>= 6.67 - <= 6.78

Remarks on result:

other: Temperature ± 0.1 °C; Solubility ± 5.2, (RDS% = 8.4)

Calibration

Six concentration levels were used: 0.5, 0.75, 1, 1.5, 2, and 3.5 μg/mL. The calibration graph was calculated applying linear regression.

Table 2: Summary of Standard Curve Parameters 

Date	Intercept	Slope	Correlation Coefficient
08 May 2013	-402571	6.67×10⁶	0.9972
09 May 2013	-701559	6.94×10⁶	0.9969
10 May 2013	-577312	5.35×10⁶	0.9991

Results of the Shake Flask Method

pH of the samples varied in the range of 6.67 – 6.78.

Samples were analysed with the above LC-MS method.

Measured concentrations are summarised in Table 3.

Table 3: Results of the determination of test item concentrations

Measured concentration after 24 hours (g/L)	pH	Measured concentration after 48 hours (g/L)	pH	Measured concentration after 72 hours (g/L)	pH	Solubility of the test material (g/L)
57.7	6.76	53.5	6.71	62.3	6.70	58.4 ± 5.2
58.3	6.78	54.0	6.67	63.0	6.69
59.9	6.75	54.1	6.69	63.2	6.71
Mean: 58.7	-	Mean: 53.9	-	Mean: 62.8	-	RSD% = 8.4

Conclusions:

Interpretation of results (migrated information): very soluble (> 10000 mg/L)
Under the conditions of the test, the water solubility of the test material was determined to be 58.4 ± 5.2 g/L (95% confidence interval) at 20 °C ± 1°C using the shake-flask method.

Executive summary:

The water solubility of the test material was determined in a study performed under GLP conditions and in line with the standardised guidelines OECD 105 and EU Method A.6. Since the expected water solubility was above 10^-2g/L, the flask method was applied.

The substance (5.00 g) is dissolved in water (20 mL) and agitated at 30 °C. The theoretical concentration of the solution is 250 mg/mL, assuming total dissolution of the test material.

After one day, three flasks and one control were removed and re-equilibrated at 20 °C for 24 hours. The concentration in the clear solvent phase was determined by LC-MS. The other flasks were treated similarly after initial equilibration at 30 °C for two and three days, respectively. The pH of each sample was recorded.

Before the analysis samples were centrifuged, 100-fold and 500-fold diluted in two consecutive steps. Three replicate dilutions were carried out using methanol.

Under the conditions of the test, the water solubility of the test material was determined to be 58.4 ± 5.2 g/L (95% confidence interval) at 20 °C ± 1°C using the shake-flask method.

Description of key information

Water solubility: 58.4 g/L at 20°C, OECD 105 and EU Method A. 6, Sárvári 2013c.

Key value for chemical safety assessment

Water solubility:

58.4 g/L

at the temperature of:

20 °C

Additional information

In the key study (Sárvári, 2013c) the water solubility of the test material was determined in a study performed under GLP conditions and in line with the standardised guidelines OECD 105 and EU Method A. 6. Since the expected water solubility was above 10^-2g/L, the flask method was applied.

The substance (5.00 g) is dissolved in water (20 mL) and agitated at 30 °C. The theoretical concentration of the solution is 250 mg/mL, assuming total dissolution of the test material. After one day, three flasks and one control were removed and re-equilibrated at 20 °C for 24 hours. The concentration in the clear solvent phase was determined by LC-MS. The other flasks were treated similarly after initial equilibration at 30 °C for two and three days, respectively. The pH of each sample was recorded. Before the analysis samples were centrifuged, 100-fold and 500-fold diluted in two consecutive steps. Three replicate dilutions were carried out using methanol.

Under the conditions of the test, the water solubility of the test material was determined to be 58.4 ± 5.2 g/L (95% confidence interval) at 20 °C ± 1°C using the shake-flask method.