Lupine, L. albus, ext.

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

April 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Remarks:

The study was conducted according to an internationally recognised method. No deviation was reported. Test substance is adequately specified. Therefore full validation applies.

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

not specified

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

not specified

GLP compliance:

no

Type of method:

flask method

Key result

Water solubility:

ca. 581 g/L

Conc. based on:

test mat.

Loading of aqueous phase:

1 500 g/L

Temp.:

30 °C

pH:

ca. 7

Remarks on result:

other: The water solubility of the substance was determined as 581 g/L at 30 ± 0.5°C (pH = 7). The conditions of the test were: a loading rate of 1500 ± 30 g/L and a water content of 4.2% w/w (dry matter result obtained on the powder).

Results and discussion

1-Preliminary test

Solution

Sample weight (g)

Volume of water (mL)

Concentration (g/L)

Kathon^®(drops)

Initial pH

Test temperature (°C)

Mixing

Final pH

Visual appearance

T1

6.4578

6

1076.3

5

7

21

10 minutes

7

Small amount of undissolved powder

Dissolution test T1 at 1076.3 g/L of test item in water revealed a low solubility. The powder is not fully solubilized.

 

Solution

Sample weight (g)

Volume of water (mL)

Concentration (g/L)

Kathon^®(drops)

Initial pH

Test temperature (°C)

Mixing

Final pH

Visual appearance

Range of solubility (g/L)

T2

6.4578

30

215.3

5

7

21

10 minutes

7

Clear and totally dissolved

200-1000

Dissolution test T2 at 215.3 g/L revealed a very good solubility because the totality of test item was dissolved (visual control).

 

According to this preliminary OECD 105 test, the range of solubility of the test item in water is [200 g/L - 1000 g/L]at room temperature.

 

2-Flask method

a.  Preparation of solutions

Based on conclusion of the first preliminary test, the solubility of the test item was determined to be between 200 and 1000 g/L. In order to saturate the test solution, OECD 105 recommends to prepare a solution whose concentration is 5 x 1000 g/L, i.e. 5000 g/L.

But at such concentration, the solution of test item is very viscous and has many lumps preventing any agitation. Therefore, for technical reasons, it was decided to progressively add mass of test item to a defined volume of water until the maximal saturation was reached according to a visual control.

The results are listed in the following table:

Volume of water (mL)	Powder weight (g)	Concentration (g/L)	Visual appearance
3	2.7309	900	Totally dissolved
	2.8852	950
	3.0291	1000	Thickened solution
	3.1823	1050
	3.3537	1100
	3.5111	1150
	3.6481	1200
	3.7917	1250	Viscous solution - Mixing slow but regular Undissolved powder observed
	3.9401	1300
	4.0929	1350
	4.2652	1400
	4.4237	1450
	4.5889	1500

The maximal saturated concentration obtained by visual control was 1500 g/L at room temperature. This loading rate will be considered for the main test.

 

Three flasks were prepared at a loading rate close to 1500 g/L for equilibration for 24, 48 and 72 hours at 30 ± 0.5°C.

	Solution	Sample weight (g)	Water (mL)	Saturated concentration (g/L)	Initial pH	Temperature (°C)	Mixing	Equilibration	Final pH	Visual appearance	Centrifugation
TEST	T1	4.5885	3	1529.5	7	30	24h	24h	7	Brown orange	4000 rpm 10 minutes
	T2	4.4306	3	1476.9	7	30	24h	48h	7	Brown orange	4000 rpm 10 minutes
	T3	4.5117	3	1503.9	7	30	24h	72h	7	Brown orange	4000 rpm 10 minutes

The observations made during for the three equilibration times were similar.

b.  Determination of the dry matter content of saturated solutions

The concentration of the test item dissolved in water was determined using dry matter assay method RD-ANA-MSG-I-047.

Three drying times in a 105°C oven were tested on test item at 1010.15 g/L in duplicate: 7, 24 and 48 hours.

 

	0h		7h			24h			48h
Replicas	Tare weight (g)	Full weight (g)	Dry weight (g)	DM content (g/L)	Mean DM of powder (mg/g)	Dry weight (g)	DM content (g/L)	Mean DM of powder (mg/g)	Dry weight (g)	DM content (g/L)	Mean DM of powder(mg/g)
a	12,5631	15,6959	14,0921	488,06	488,46	14,0739	482,25	482,23	14,0675	480,21	480,13
b	12,7285	16,0538	14,3541	488,86		14,3320	482,21		14,3248	480,05

 

The results for the drying times between 7h and 48h were similar (RSD = 1.8 %) and so it was decided to use the drying time of 7 hours.

Solutions were analyzed in duplicate and the results are listed in the following table:

 

	Solution	Replicas	Tare weight (g)	Full weight (g)	Dry weight 7 h (g)	DM content 7 h (g/L)	Mean DMTSi (1)   (g/L)	Uncertainty (g/L) (2)	Amplitude (g/L) (3)	Compliant (Y/N) (4)	Mean (DMmean) (5) (g/L)	Uncertainty (g/L) (6)	Amplitude (g/L) (7)	Compliant (Y/N) (8)
TEST	T1	a	11.3229	13.8714	12.7440	557.6	557.2	23.4	0.8	O	556.8	27.6	3.3	Y
		b	11.9698	15.1246	13.7263	556.8				O
	T2	a	13.0471	16.2521	14.8993	559.2	558.3	23.4	1.8	O
		b	12.6081	15.4279	14.1799	557.4				O
	T3	a	11.7086	14.5683	13.2941	554.4	555.0	23.3	1.1	O
		b	13.1147	15.9040	14.6641	555.5				O

The three dry matter contents determined (DM_T1, DM_T2and DM_T3) did not differ by more than 15%, (RSD = 0.3 %) and so the results are validated according to OECD method No. 105.

The dry matter content of saturated solutions of test item was 557 g/L at 30 ± 0.5 °C (pH = 7) for a loading rate of approximately 1500 +/- 30 g/L (without correction of water contained in the test item).

a.  Determination of the water contentof the test product

The dry matter content of the powder was assayed in order to determine the water content .

Three drying times in a 105°C oven were tested: 24, 40 and 48 hours.

 

	0h		24h			40h			48h
Replicas	Tare weight (g)	Full weight (g)	Dry weight (g)	DM content (g/L)	Mean DM of powder (mg/g)	Dry weight (g)	DM content (g/L)	Mean DM of powder (mg/g)	Dry weight (g)	DM content (g/L)	Mean DM of powder(mg/g)
a	50,0290	51,0543	51,0135	960,21	960,03	51,0124	959,13	958,34	51,0122	958,94	957,84
b	44,9651	45,9591	45,9192	959,86		45,9169	957,55		45,9161	956,74

 

The results between 24 and 48 hours were similar (RSD = 0.1%) and so it was decided to use the powder of dried for40 hours.

Samples were analyzed in duplicate and the results are listed in the following table:

 

	Replicas	Tare weight (g)	Full weight (g)	Sample weight at 40 h (g)	DM content at 40 h (mg/g)	Mean DM of powder (9) (mg/g)	Uncertainty (mg/g) (10)	Amplitude (mg/g) (11)	Compliant (Y/N) (12)	Water content (13) (%)	Mean water content (%) Cwater mean (14)
Sample	a	50.0290	51.0543	51.0124	959.1	958.3	40.2	1.6	Y	4.1	4.2
	b	44.9651	45.9591	45.9169	957.5				Y	4.3

The water content of the test item powder was 4.2% w/w, in compliance with the result reported in the Certificate of analyses provided in attachment.

Determination of water solubility of the test product

With:

 

Mean dry matter: DMmean(g/L)	Mean water content: Cwater mean (%)	Water solubility (g/L) at 30 ± 0.5°C (pH = 7), for a loading rate of 1500 ± 30 g/L and considering that the test item contains 4.2% w/w of water
557	4.2	581

Conclusions:

According to OECD method No. 105, the water solubility of the test item was determined as 581 g/L at 30 ± 0.5°C (pH=7), for a loading rate of  1500 ± 2 g/L and considering that the test item contains 4.2%w/w of water (dry matter result obtained on the powder).

Executive summary:

A non-GLP study using flask method according to OECD method 105 and EU. A6 was conducted to determine the water solubility of the test item.

The water solubility ofthe test item was determined as 581 g/L at 30 ± 0.5°C (pH=7), for a loading rate of 1500 ± 2 g/L and considering that the test item contains 4.2% w/w of water (dry matter result obtained on the powder).

Description of key information

The water solubility of test item was determined as 581 g/L at 30 ± 0.5°C (pH = 7).

Key value for chemical safety assessment

Water solubility:

581 g/L

at the temperature of:

30 °C

Additional information

A non-GLP study using flask method according to OECD method 105 and EU. A6 was conducted to determine the water solubility of the test item.

The water solubility of the test item was determined as 581 g/L at 30 ± 0.5°C (pH=7), for a loading rate of 1500 ± 2 g/L and considering that the test item contains 4.2%w/w of water (dry matter result obtained on the powder).