Reaction mass of calcium 2,6-bis(3-carboxylatopropanamido)hexanoate and isomers of calcium amino-(3-carboxylatopropanamido)hexanoate

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

10 April 2017 - 13 July 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:

July 27, 1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Version / remarks:

March 2014

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7840 (Water Solubility)

Version / remarks:

March 1998

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Key result

Water solubility:

93.39 g/L

Conc. based on:

test mat. (dissolved fraction)

Incubation duration:

>= 1 - <= 3 d

Temp.:

20 °C

pH:

ca. 9.9

Remarks on result:

other: water solubility of one constituent

Key result

Remarks on result:

other: It was concluded that no single water solubility for the test substance could be stated.

Preliminary test: The water solubility of the test item from saturated solution was estimated to be 20 g/L. After sonication the test item was observed to be dissolved completely, but after centrifugation there were undissolved parts remaining at the bottom of the centrifuge tube.

Calibration:

The calibration solutions were prepared in 0.2 - 20 μg/mL range. The calibration samples were analysed by HPLC with three parallel injections from each. The test items concentrations were calculated with the help of the calibration equation (see regression data).

Table 1. Data of the calibration on 13 April 2017 for the Preliminary Test

Concentration of the test item (µg/mL)	Mean of the Peak Areas of test item (n=3)	Accuracy (absolute value) %
0.21	6950	14
0.52	17067	5
1.04	34191	2
2.1	68824	1
5.2	168668	0
10.4	341612	1
20.8	670861	0

Table 2. Data of the calibration on 21 April 2017 for the Main Test

Concentration of the test item (µg/mL)	Mean of the Peak Areas of test item (n=3)	Accuracy (absolute value) %
0.21	7189	8
0.52	17737	2
1.04	34834	2
2.1	71072	2
5.2	172733	0
10.4	348406	1
20.8	690668	0

Table 3. Regression data

Analytical occasion	constant	X Coefficient	R.Squared
13 April 2017	1169	32299	0.9999
21 April2017	861	33209	1.0000

Table 4. Results of the determination of water solubility of the test item

Pre-incubation period	Measured concentration of Retardan 200 P (g/L)		Measured pH
	Test vessels	Mean
24 h	81.42	*79.47	9.94
	72.51		10.00
	84.49		9.98
48 h	93.91	93.62	9.96
	91.44		9.97
	95.51		9.89
72 h	92.78	93.15	9.94
	93.86		9.92
	92.82		9.93
Solubility of the test item (g/L)		93.39	-
Confidence interval (95 %)		1.45	-
RSD%		1	-
Ultrapure water		-	5.7 – 5.8

* Measured concentration between the 24 and 48 hour pre-incubation period samples differ by more than 15 %, therefore, the result of the 24 hour pre-incubation period was not used for the calculation.

Conclusions:

The determination of the water solubility of the test item reveals different results for the individual constituents. For the constituent of the test item which was measured by the HPLC method it is concluded that the test item completely recovered. The water solubility of this constituent was determined to be 93.39 ± 1.45 g/L (95 % confidence interval) at 20 ± 0.5 °C using the shake-flask method for the performance of the main test.
During the preliminary test above 10 g/L concentration precipitate was observed. Thus, it was concluded that the water solubility of one constituent of the test item is 10 g/L. Based on these results, it was concluded that no single water solubility for the test item could be stated.

Executive summary:

A study according OECD TG 105, EU method A.6 and EPA OPPTS 830.7840 was conducted to evaluate the solubility ofthe test item in water at 20 ± 0.5 °C. A preliminary test for solubility was carried out as a range finding test for the decision whether the column elution method or the flask method has to be used for the performance of the main test. The solubility of the test item was higher than 10 mg/L. Therefore the shake-flask method was used for the main test. The determination of the water solubility of the test item reveals different results for the individual constituents. For the constituent of the test item which was measured by the previously validated HPLC method it is concluded that the test item completely recovered. The water solubility of this constituent was determined to be 93.39 ± 1.45 g/L (95 % confidence interval) at 20 ± 0.5 °C using the shake-flask method for the performance of the main test. During the preliminary test above 10 g/L concentration precipitate was observed. Thus, it was concluded that the water solubility of one constituent of the test item is 10 g/L. Based on these results, it was concluded that no single water solubility for the test item could be stated.

Description of key information

The determination of the water solubility of the test item reveals different results for the individual constituents. For the constituent of the test item which was measured by the HPLC method it is concluded that the test item completely recovered. The water solubility of this constituent was determined to be 93.39 ± 1.45 g/L (95 % confidence interval) at 20 ± 0.5 °C using the shake-flask method for the performance of the main test.

During the preliminary test above 10 g/L concentration precipitate was observed. Thus, it was concluded that the water solubility of one constituent of the test item is 10 g/L. Based on these results, it was concluded that no single water solubility for the test item could be stated. A water solubility of 10 g/L was determined as key value as a worst case approach.

Key value for chemical safety assessment

Water solubility:

10 g/L

at the temperature of:

20 °C

Additional information

A study according OECD TG 105, EU method A.6 and EPA OPPTS 830.7840 was conducted to evaluate the solubility of the test item in water at 20 ± 0.5 °C. A preliminary test for solubility was carried out as a range finding test for the decision whether the column elution method or the flask method has to be used for the performance of the main test. The solubility of the test item was higher than 10 mg/L. Therefore the shake-flask method was used for the main test. The determination of the water solubility of the test item reveals different results for the individual constituents. For the constituent of the test item which was measured by the previously validated HPLC method it is concluded that the test item completely recovered. The water solubility of this constituent was determined to be 93.39 ± 1.45 g/L (95 % confidence interval) at 20 ± 0.5 °C using the shake-flask method for the performance of the main test. During the preliminary test above 10 g/L concentration precipitate was observed. Thus, it was concluded that the water solubility of one constituent of the test item is 10 g/L. Based on these results, it was concluded that no single water solubility for the test item could be stated. A water solubility of 10 g/L was determined as key value as a worst case approach.