Sodium 1-amino-9,10-dihydro-4-[5-[(2-hydroxyethyl)sulphamoyl]-3,4-xylidino]-9,10-dioxoanthracene-2-sulphonate

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 107 (Partition Coefficient (n-octanol / water), Shake Flask Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient)

Deviations:

no

GLP compliance:

no

Type of method:

flask method

Partition coefficient type:

octanol-water

Specific details on test material used for the study:

Test material was a blue powder.

Analytical method:

other: UV-Vis

Type:

log Pow

Partition coefficient:

-0.05

Temp.:

20 °C

Remarks on result:

other: unknown pH

Individual Results:

Preliminary Visual Estimation of the n-octanol solubility:

Different amounts of the test item were stirred with different amounts of n-octanol at room temperature and visually checked for any undissolved particles.

 

Table: Appearance of the test mixtures

Amount of test item in mg	Volume in ml	Total volume in ml	Stirring time	Appearance of mixture
10	0.10	0.10	60 min	undissolved
10	1.00	1.00	60 min	undissolved
1	10	10	60 min	undissolved
1	20	20	60 min	dissolved

 

According to this preliminary test the solubility of the test item in n-octanol is above 50 mg/L (without correction of the purity).

 

Calculation of the partition coefficient log Pow from the preliminary tests:

The partition coefficient Pow may be estimated from the saturation concentrations in n-octanol and water by the following equation:

Pow = cs octanol /cs water

s = saturation

With the data obtained from the preliminary experiments above (octanol solubility cs = 50 mg/L) and in the preliminary test (water solubility: cs = 1.2 g/L) the partition coefficient was calculated as log POW -1.4.

 

Determination of the solubility in the n-Octanol phase: Flask Method

Table: Solubility of the test item –experiments A to D

Experiment	A	B	C	D (blank)
Amount of test item (mg)	1000	1000	1000	--
Stirring time at 30 °C (h)	24	48	72	72
Aliquot of the flasks (mL)	1/4	1/4	1/4	1/4
End volume (mL)	5	5	5	5
Measured concentration (μg/mL)	9.75	9.25	9.80	--
Solubility (mg/L)	39	37	39	--

 

The values of the measured concentrations of the test item in n-octanol is 39 mg/L.

 

Table: Concentrations of the standards for recheck:

Standard	Measured concentration (μg/mL)	% Recovery
Standard B + 10.8 μg test item	21.5	98.1

 

Recovery of 98.1 % indicates a sufficient accuracy of the analytical method.

 

Shake Flask method:

 

Experiment Ratio octanol/water	A (Ratio 1:1)	B (Ratio 1:2)	C (Ratio 2:1)
Stock solution in mg/100 mL	13.1	13.1	13.1
Stock solution in ml	4	4	8
Flask concentration in μg	524	524	1048
Water volume (mL)	4	4	8
Measured concentration n-octanol phase (mg/L)	58.28	69.52	41.44
Measured concentration water phase (mg/L)	67.40	85.49	42.07
Pow	0.865	0.810	0.980
Log Pow	-0.06	-0.09	-0.01

Conclusions:

The partition coefficent n-octanol/water of the test item at 20 °C was determined to be -0.05 (log Pow).

Executive summary:

The n-octanol/water partition coefficient of FAT 20033/L was determined in a study conducted according to OECD Guideline 107 and 117. The flask method was used for the purpose. A stock solution of the test item was prepared in water (pre-saturated with n-octanol): 13.1 mg/100 mL. Three different experiments (double determination) were started with following ratios of n-octanol/water: A (1:1); B (1:2); C (2:1). After phase separation by centrifugation, the total concentration of the test substance was determined by UV-spectroscopy (255 nm) at 20 °C in each phase. UV/VIS was used for the test substance concentration determination. Based on the measured concentrations in n-octanol and water, the partition coefficent n-octanol/water of the FAT 20033/L at 20 °C was determined to be -0.05 (log Pow).

Description of key information

The n-octanol/water partition coefficient of FAT 20033/L was determined to be -0.05 (log Pow).

Key value for chemical safety assessment

Log Kow (Log Pow):

-0.05

at the temperature of:

20 °C

Additional information

The n-octanol/water partition coefficient of FAT 20033/L was determined in a study conducted according to OECD Guideline 107 and 117. The flask method was used for the purpose. A stock solution of the test item was prepared in water (pre-saturated with n-octanol): 13.1 mg/100 mL. Three different experiments (double determination) were started with following ratios of n-octanol/water: A (1:1); B (1:2); C (2:1). After phase separation by centrifugation, the total concentration of the test substance was determined by UV-spectroscopy (255 nm) at 20 °C in each phase. UV/VIS was used for the test substance concentration determination. Based on the measured concentrations in n-octanol and water, the partition coefficient n-octanol/water of the FAT 20033/L at 20 °C was determined to be -0.05 (log Pow).