Sodium 2-[[4-(cyclohexylamino)-9,10-dihydro-9,10-dioxo-1-anthryl]amino]-5-ethoxybenzenesulphonate

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

March from 12th to 14th, 2018

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)

Version / remarks:

adopted: 27 July 1995

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 105 (Water Solubility)

Version / remarks:

adopted: 27 July 1995

GLP compliance:

yes

Type of method:

other: individual solubility in water and octanol

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Type:

log Pow

Partition coefficient:

-0.87

Temp.:

20 °C

pH:

8.6 - 8.7

Details on results:

Partition coefficient of test item was determined by adopting solubility’s from the individual solvents i.e., water and octanol. The test item was performed in triplicates at a temperature of 20 °C.
The solubility of test item in n-octanol was determined to be 0.599 g/l with 0.17 % of RSD for replicates. The pH of octanol samples were recorded as 8.64, 8.66 and 8.67 during the experimental phase.
The solubility in Milli-Q water was determined to be 4.435 g/l with 0.45 % of RSD for replicates. The pH of samples water were recorded as 8.58, 8.60 and 8.57 during the experimental phase.
The individual solubility’s in the respective solvents, the partition coefficient was calculated from the ratio of solubility in n-octanol and milli-Q water is found to be -0.87 log Pow.

Individual solubilities

Standard conc. (mg/l)	Dilution Factor	Conc. obtained (g/l)	Mean conc. obtained (g/l)	± SD	% RSD
Solubility in n-octanol
0.42	2500	0.599	0.599	0.001	0.17
0.42	2500	0.598
0.42	2500	0.601
0.42	2500	0.598
0.42	2500	0.598
0.42	2500	0.599
Solubility in Milli-Q-water
0.42	5000	4..45	4.435	0.020	0.45
0.42	5000	4.44
0.42	5000	4.45
0.42	5000	4.45
0.42	5000	4.41
0.42	5000	4.41

Conclusions:

log Pow: -0.87 at 20 °C and pH 8.6 - 8.7

Executive summary:

The partition coefficient of test item was determined from individual solubility in octanol and water. The testing procedures and method were in accordance to the indications outlined into the OECD guidelines 107 and 105. For test substance identification and quantification, a analytical HPLC-UV method was validated, in accordance with SANCO/3029/99. Saturated n-Octanol and Milli-Q Water were prepared in separate bottles and the experiment was performed in triplicates at a temperature of 20 °C.

The solubility of test item in n-octanol was determined to be 0.599 g/l with 0.17 % of RSD for replicates. The solubility in Milli-Q water was determined to be

4.435 g/l with 0.45 % of RSD for replicates.

Based on the individual solubilities in the respective solvents, the partition coefficient was calculated to be logPow = -0.87 at 20 °C and pH 8.6 - 8.7.

Conclusion

log Pow: -0.87 at 20 °C and pH 8.6 - 8.7

Description of key information

log Pow: -0.87 at 20 °C and pH 8.6 - 8.7

Key value for chemical safety assessment

Log Kow (Log Pow):

-0.87

at the temperature of:

20 °C

Additional information

OECD 107 and 105 - estimation method (solubility ratio)