Enzymatic hydrolysis products of Ophiopogon japonicus, Liliaceae, root

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

March 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. 484 g/L

Conc. based on:

test mat.

Loading of aqueous phase:

1 158 g/L

Temp.:

30 °C

pH:

ca. 5

Remarks on result:

other: the water solubility of OF14 AT was determined as 484 g/L at 30 ± 0.5°C (pH=5), for a loading rate of 1158 ± 2 g/L and considering that the test item contains 3.5%w/w of water (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

6.0500

6

1008.33

5

/

21

10 minutes

/

Viscous – undissolved powder

Dissolution test T1 at 1008.33 g/L of OF14 AT in water revealed very low solubility. The test solution was viscous and the powder was 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)

E2

6.0500

30

201.67

5

5

21

10 minutes

5

Clear and totally dissolved

200-1000

Dissolution test T2 at 201.67 g/L revealed good solubility because the totality of OF14 AT was dissolved (visual control).

 

According to this preliminary OECD 105 test, the range of solubility of OF14 AT in water was [200 g/L - 1000 g/L] at room temperature.

2- Flask method

Based on conclusion of the first preliminary test, the solubility of OF14 AT was determined to be between 200 and 1000 g/L. In order to saturate the test solution, a solution should be prepared whose concentration is 5 x 1000 g/L, i.e. 5000 g/L.

But during the preliminary test, it was found undissolved powder at a concentration of 1000 g/l. The maximal saturated concentration should be around 1000 g/l.

It was decided to progressively add mass of test item to a defined volume of water until “maximal saturation was reached according to a visual control. This pre-test was performed at room temperature.

 

The resultsare listed in the following table:

 

Volume of water (ml)	Powder weight (g))	Concentration (g/L)	Visual appearance
10	6,5	650	Powder fully solubilized
	7,0	700
	7,5	750	Suspension powder then dissolved after a few minutes of stirring
	8,0	800
	8,5	850
	9,0	900
	9,5	950
	10,0	1000
	10,5	1050
	11,0	1100	Powder in suspension
	11,5	1150	Formation of lumps

The “maximal saturated” concentration obtained by visual control in this pre-test was1100 g/L at room temperature.[BC3] This loading rate will be considered for the main test.

 

Three flasks were preparedat a loading rate of about 1100g/L for equilibration for 24, 48 and 72 hours at 30 ± 0.5°C.

 

	Solution	Sample weight (g)	Water (mL)	“Saturated concentration” (g/L) = loading rate	Initial pH	Temperature (± 0.5°C)	Mixing	Equilibration (occasional shaking made morning and evening)	Final pH	Visual appearance	Centrifugation
TEST	T1	11,5668	10	1156,7	5	30	24h	24h	5	Clear yellow	4000 rpm 10 minutes
	T2	11,5929	10	1159,3	5	30	24h	48h	5	Clear yellow	4000 rpm 10 minutes
	T3	11,5653	10	1156,5	5	30	24h	72h	5	Clear yellow	4000 rpm 10 minutes

The three tests yielded similar results and so the study could be continued.

 

Determination of the dry matter content (DM)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 in duplicate: 7, 24 and 48 hours.

 

	0h		7h			24h			48h
Replicas	Tare weight (g)	Full weight (g)	Sample weight (g)	DM content (mg/g)	Mean DM of powder (mg/g)	Sample weight (g)	DM content (mg/g)	Mean DM of powder (mg/g)	Sample weight (g)	DM content (mg/g)	Mean DM of powder (mg/g)
a	12,1520	15,2566	13,6626	486,57	486,22	13,6291	475,78	475,73	13,6058	468,27	468,06
b	12,1682	15,3083	13,6939	485,88		13,6619	475,69		13,6373	467,85

 

The results for the drying times between 7h and 48h were similar (RSD=1.9%) and so it was decided to use the drying time of 24 hours.

 

 

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

 

	Solution	Replicas	Tare weight (g)	Full weight (g)	Dry weight 24 h (g)	DM content 24 h (g/L)	Mean DMTi (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	12.0664	15.9321	13.8399	458.8	459.9	19.3	2.2	Y	467.3	23.1	12.3	Y
		b	12.8604	16.4737	14.5260	461.0				Y
	T2	a	13.0698	16.8876	14.8682	471.1	469.7	19.7	2.7	Y
		b	12.3710	15.6635	13.9133	468.4				Y
	T3	a	11.7756	14.7921	13.1812	466.0	472.2	19.8	12.4	Y
		b	12.1521	15.7050	13.8518	478.4				Y

The results from vessels 1, 2 and 3 show a tendency of increasing values. However, the three dry matter contents determined (DM_T1, DM_T2and DM_T3) did not differ by more than 15%, (RSD=1.39%) and so the results were validated according to OECD method No. 105.

 

The dry matter content of saturated solutions of OF14 AT was 467 g/L at 30 ± 0.5 °C (pH 5) for a loading rate of approximately 1158 +/- 2g/L (without correction of water contained in OF14 AT

Determination of the water content of the test product

The dry matter content of the powder was assayed in order to determine the water content of OF14 AT.

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)	Sample weight (g)	DM content (mg/g)	Mean DM of powder (mg/g)	Sample weight (g)	DM content (mg/g)	Mean DM of powder (mg/g)	Sample weight (g)	DM content (mg/g)	Mean DM of powder (mg/g)
a	44,9655	45,8862	45,8445	954,71	955,20	45,8439	954,06	953,4	45,8435	953,62	952,93
b	44,8850	45,9547	45,9073	955,69		45,9042	952,79		45,9036	952,23

The results at 24, 40 and 48 hours were similar (RSD = 0.13%) and so it was decided to use the powder of dried for40 hours.

 

OF14 AT samples were analyzed in duplicate and the results were 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) (%w/w)	Mean water content (%w/w) Cwater mean (14)
Sample	a	45.1363	46.2242	46.1846	963.6	964.9	40,5	2.7	Y	3.6	3.5
	b	44.7146	45.6547	45.623	966.3				Y	3.4

 

The water content of OF14 AT powder was 3.5%w/w, in compliance with the result reported in the Certificate of analyses provided in attachment.

 

Determination of water solubilityof 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=5), for a loading rate of 1158 ± 2 g/L and considering that the test item contains 3.5%w/w of water
467	3.5	483.9

 

Conclusions:

According to OECD method No. 105, the water solubility of OF14 AT was determined as 484 g/L at 30 ± 0.5°C (pH=5), for a loading rate of 1158 ± 2 g/L and considering that the test item contains 3.5%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 OF14 AT.

The water solubility of OF14 AT was determined as 484 g/L at 30 ± 0.5°C (pH=5), for a loading rate of 1158 ± 2 g/L and considering that the test item contains 3.5%w/w of water (dry matter result obtained on the powder).

Description of key information

The water solubility of OF14 AT was determined as 484 g/L at 30 ± 0.5°C (pH=5).

Key value for chemical safety assessment

Water solubility:

484 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 OF14 AT.

The water solubility of OF14 AT was determined as 484 g/L at 30 ± 0.5°C (pH=5), for a loading rate of 1158 ± 2 g/L and considering that the test item contains 3.5%w/w of water (dry matter result obtained on the powder).