1-Propanaminium, N-(3-aminopropyl)-2-hydroxy-N,N-dimethyl-3-sulfo-, N-(C12-18(even numbered) acyl) derivs., hydroxides, inner salts

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

water solubility

Remarks:

expressed as Critical Micelle Concentration (CMC)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

March 19th, 2018 - September 21st, 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Qualifier:

no guideline available

Principles of method if other than guideline:

The design of this study was based on EC Guideline A.5 (Surface Tension - March 04, 2016) and OECD Guideline 115 (Surface Tension of Aqueous Solutions - July 27, 1995). The Critical Micelle Concentration (CMC) was determined by measuring the surface tension of test item solutions at different test item concentrations. For surface active substances which form micelles in solution, the surface tension decreases with increasing concentration until the CMC is reached. At concentrations above the CMC, the surface tension remains constant.

GLP compliance:

yes (incl. QA statement)

Type of method:

other: OECD harmonized ring method

Water solubility:

809 mg/L

Conc. based on:

test mat.

Temp.:

20 °C

Remarks on result:

other: water solubility expressed as Critical Micelle Concentration (CMC)

Key result

Water solubility:

402 mg/L

Conc. based on:

other: solid content

Temp.:

20 °C

Remarks on result:

other: water solubility expressed as Critical Micelle Concentration (CMC)

The CMC was determined from the intersection of the two trend lines y1 and y2. Trendline y1 was obtained using the data of the test solutions with test item concentrations of 1, 10, 40, 70, 100 and 201 mg solids/L. Trendline y2 was obtained from the mean surface tension of the test solutions with test item concentrations of 503, 1003, 3998, 7008 and 10008 mg solids/L. The intersection was calculated to be at a log C value of 2.60. It corresponded with a CMC of 402 mg solids/L (equivalent to a CMC of 809 mg test item/L).

Conclusions:

The CMC of the test item was determined by measuring the surface tension of test item solutions at different test item concentrations. The CMC of the test item was 809 mg test item/L, equivalent to a CMC of 402 mg solid content/L.

Executive summary:

The Critical Micelle Concentration (CMC) of the test item (= substance EC 939-455-3 in aqueous commercial product) was determined in a GLP-compliant study by measuring the surface tension of test item solutions at different test item concentrations. The CMC of the test item was 809 mg/L, equivalent to a CMC of 402 mg solid content/L.

Reference 2

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 16 May 2012 to 25 January 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

2012-12-15

Type of method:

flask method

Key result

Water solubility:

> 500 g/L

Conc. based on:

test mat.

Temp.:

20 °C

pH:

>= 8.56 - <= 8.64

Preliminary test results:

Through the serial volume addition of water to the test item, it was shown that the water solubility of the test item was estimated to be higher than 200 g/L at 20 ± 1.0 °C. Based on this result, it was decided to made the main test with water at a concentration of 500 g/L.

Main test results:

The following table show the data used for the determination of the calibration curve.

Reference of calibration solution	RUN	Peak area (area units)	Conc (mg/L)	Response factor	Final Volume (ml)	Dilution factor	Sample weight (mg)	Conc back-calc	Diff
		A	C= (w*P)/(V*Df)	RF = A/C	V	Df	w	C'= (A-b)/a	%
Lin 50%	L002	3855199	39.71	9.70946E+04	100	1.0	10.34	40.11	1.01%
Lin 50%	L003	3891853	39.71	9.80177E+04	100	1.0	10.34	40.49	1.99%
Lin 75%	L004	5422447	57.14	9.48989E+04	100	1.0	14.88	56.65	-0.84%
Lin 75%	L005	5433634	57.14	9.50947E+04	100	1.0	14.88	56.77	-0.65%
Lin 100%	L006	7374440	78.84	9.35425E+04	100	1.0	20.53	77.27	-1.99%
Lin 100%	L007	7468601	78.84	9.47369E+04	100	1.0	20.53	78.26	-0.74%
Lin 125%	L008	9266255	96.38	9.61389E+04	100	1.0	25.10	97.24	0.89%
Lin 125%	L009	9296883	96.38	9.64567E+04	100	1.0	25.10	97.56	1.22%
Lin 150%	L010	10663622	112.59	9.47130E+04	100	1.0	29.32	111.99	-0.52%
Lin 150%	L011	10754715	112.59	9.55221E+04	100	1.0	29.32	112.96	0.33%

The calibration curve used for the determination of the test item concentration in the analytical solutions was equal to :

Peaks area = 94709 * (C in mg/l) + 56748

The following concentrations were obtained in the solutions prepared for the hydrosolubility determination:

		Reference of calibration solution	Peak area (area units)	Peak area mean (area units)	Conc (mg/L)	Dilution Factor	Final conc test item C12 (g/l)	Final conc test item (g/l)	Sample weight (mg)	Volume added (ml)	Theoretical conc (g/l)	Recovery %
	pH			A	C= A-b/ a (cal)	F	Cf = C*F /1000	Cf' = Cf / 0,384	w	V	T = W*100/ ((w/d)+V)	R = Cf' /T
After 24 h	8,56	12-091 1 dil2500	8190397	8157495	85.5	2500	214	557	10.01245	10	550	1,01
		12-091 1 dil2500	8124593
	8,61	12-091 2 dil2500	7920542	7952601	83.4	2500	209	544	10.01456	10	550	0,99
		12-091 2 dil2500	7984660
After 48 h	8,59	12-091 3 dil2500	8178539	8143775	85.4	2500	214	557	10.00240	10	550	1,01
		12-091 3 dil2500	8109011
	8,64	12-091 4 dil2500	8253107	8269688	86.7	2500	217	565	10.02856	10	550	1,03
		12-091 4 dil2500	8286269
After 72h	8,63	12-091 5 dil2500	7851170	7916528	83.0	2500	208	542	9.97568	10	549	0,99
		12-091 5 dil2500	7981886
	8,6	12-091 6 dil2500	8388785	8388389	88.0	2500	220	573	10.07985	10	552	1,04
		12-091 6 dil2500	8387993

pH was taken at 20°C

The mean results are summarized in the following table

Mean value C12 (g/l)	Mean value test item (g/l)	Mean recovery (%)	RSD (%)
214	556	101	2,1

The observed mean concentration of test item is equal to 556 g/L with an RSD of 2.1% using starting solutions obtained with about 10 g of test item

and 10 mL of water.

Conclusions:

The solubility of test item in water is higher than 500 g/L at 20.0 ± 1.0 °C. The obtained experimental value is equal to 556 g/L using starting solutions obtained with about 10 g of test item and 10 mL of water.

Executive summary:

The water solubility of the test item (= substance EC 939-455-3) was investigated in a GLP-compliant study performed in accordance withOECD Guideline 105 (Water Solubility) and EU Method A.6 (Water Solubility). The solubility of the test item in water was found to be higher than 500 g/L at 20.0 ± 1.0 °C. The experimental value obtained is equal to 556 g/L using starting solutions obtained with about 10 g of test item and 10 mL of water. The analytical method used for the test was validated on the basis of the most important constituent represented by the C12 fraction in the test item.

Reference 3

Endpoint:

water solubility

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
C8-C18 AAPHS and C12-18 AAPHS have the same functional groups, and general composition. The main variable resides in the alkyl chain distribution.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
Source chemical = C8-18 cocamidopropyl hydroxysultaine (EC 939-455-3).
Target chemical = C12-18 cocamidopropyl hydroxysultaine (EC 939-457-4).

3. ANALOGUE APPROACH JUSTIFICATION
The alkyl C-chain distribution of the source chemical significantly overlaps with the one of the target chemical, the C12-alkyl derivative being the major constituent in both chemicals. The structural differences in side C-chains is not expected to lead to significant differences on phys-chem properties.

4. DATA MATRIX
See "Documentation and scientific justification of the read-across approach" in section 13.2.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Key result

Water solubility:

556 g/L

Conc. based on:

other: solid content

Temp.:

20 °C

pH:

>= 8.56 - <= 8.64

Remarks on result:

other: read-across from EC 939-455-3

Key result

Water solubility:

402 mg/L

Conc. based on:

other: solid content

Temp.:

20 °C

Remarks on result:

other: water solubility expressed as Critical Micelle Concentration

Remarks:

read-across from EC 939-455-3

Conclusions:

By analogy with the source substance EC 939-455-3, a water solubility of 556 g/L at 20.0 ± 1.0 °C was reported for the target substance 1-Propanaminium, N-(3-aminopropyl)-2-hydroxy-N,N-dimethyl-3-sulfo-, N-(C12-18(even numbered) acyl) derivs., hydroxides, inner salts (EC 939-457-4).

As well, by analogy, by analogy with the source substance EC 939-455-3, a Critical Micelle Concentration of 402 mg/L was reported for the target substance 1-Propanaminium, N-(3-aminopropyl)-2-hydroxy-N,N-dimethyl-3-sulfo-, N-(C12-18(even numbered) acyl) derivs., hydroxides, inner salts (EC 939-457-4).

Description of key information

As the water solubility of the substance EC 939-457-4 has not been determined experimentally, a read-across approach was followed to fill in the endpoint. The water solubility of a structural analogue substance (= source substance EC 939-455-3) was investigated in a GLP-compliant study (Ricau, 2013) performed in accordance with OECD Guideline 105 (Water Solubility) and EU Method A.6 (Water Solubility). The solubility of the analogue substance was 556 g/L at 20.0 ± 1.0 °C. By analogy, a water solubility of 556 g/L at 20.0 ± 1.0 °C was reported for the target substance 1-Propanaminium, N-(3-aminopropyl)-2-hydroxy-N,N-dimethyl-3-sulfo-, N-(C12-18(even numbered) acyl) derivs., hydroxides, inner salts. numbered) acyl) derivs., hydroxides, inner salt (EC 939-457-4).

In addition, the Critical Micelle Concentration (CMC) of the structural analogue substance (= source substance EC 939-455-3) was determined in a GLP-compliant study (Maire, 2018) by measuring the surface tension of test solutions at different test concentrations. The CMC was 402 mg solid content/L. By analogy, a CMC of 402 mg solid content/L was reported for the target substance 1-Propanaminium, N-(3-aminopropyl)-2-hydroxy-N,N-dimethyl-3-sulfo-, N-(C12-18(even numbered) acyl) derivs., hydroxides, inner salts. numbered) acyl) derivs., hydroxides, inner salt (EC 939-457-4).

The alkyl C-chain distribution of the source substance EC 939-455-3 significantly overlaps with the one of the target substance EC 939-457-7, the C12-alkyl derivative being the major constituent in both chemicals. The structural differences in side C-chains is not expected to lead to significant differences on phys-chem properties.

Key value for chemical safety assessment

Water solubility:

556 g/L

at the temperature of:

20 °C

Additional information

The water solubility and Critical Micelle Concentration of the structural analogue (= source substance EC 939-455-3) were investigated in GLP-compliant studies (Ricau, 2013; Maire, 2018) performed in accordance with standard methods, without deviations. The studies are considered as reliable (Klimisch 1) and were selected as key studies for the endpoint of the target substance EC 939-457-4.