N-(2-(4-amino-N-ethyl-m-toluidino)ethyl)methanesulphonamide sesquisulphate

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

6 Nov 2017 to 25 Mar 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:

Estimation method was used.

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient - Shake Flask Method)

Version / remarks:

Estimation method was used.

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7550 (Partition Coefficient, n-octanol / H2O, Shake Flask Method)

Version / remarks:

Estimation method was used.

Deviations:

no

GLP compliance:

yes

Type of method:

estimation method (solubility ratio)

Partition coefficient type:

octanol-water

Type:

log Pow

Partition coefficient:

< -5.1

Temp.:

19.9 °C

Remarks on result:

other: Estimation method

Remarks:

based on water solubility and n-octanol solubility

Results

n-Octanol solubility test

The content of test item dissolved in the n-octanol sample was 8.25 mg/L.

Estimation Method

The water solubility of the test item was > 1003 g/L. Based on the results for water solubility and n-octanol solubility, the Pow value of the test item is < 8.3 x 10^-6.  This corresponds with a log Pow value of < -5.1. Therefore, no further testing was performed and estimation method was applied instead of the shake flask method.

 

Conclusion

Since Pow appeared to be very low, the estimation method was applied for the determination of the partition coefficient (Pow) of CD-3 / CAS 25646-71-3. The Pow value of the test item is < 8.3 x10^-6.  It corresponds with a log Pow value of < -5.1.

Description of key information

Log Pow value is < -5.1 at 19.9 °C (OECD 107, estimation method).

Key value for chemical safety assessment

Log Kow (Log Pow):

-5.1

at the temperature of:

19.9 °C

Additional information

The partition coefficient of the target substance was additionally evaluated by means of (Q)SAR models, using the organic fragment of the substance as representative structure. The log Pow values as estimated by the three models present in VEGA v1.1.3 are reported in the following table. The two most similar substances identified by VEGA are also included (using their CAS number), together with their similarity degree with the target component, experimental log Pow values and the predictions obtained by the QSAR models.

 

Molecule / CAS	Similarity degree	Experimental log Pow	VEGA / ALogP	VEGA / Meylan-KOWWIN	VEGA / MLogP
Target / 25646-71-3	-	n.a.	1.58	1.34	1.38
Similar / 97141-32-7	0.846	2.13	2.307	1.915	1.979
Similar / 97141-29-2	0.845	1.45	1.394	0.933	1.426

 

With respect to the calculated applicability domain index (AD Index = 0.85), the substance is suspected to be not fully compliant with the applicability domain of the three models. The performances on the similar molecules are however generally good (only the Meylan-KOWWIN prediction for 97141-29-2 gave moderate performance).

 

Based on the obtained results, the log Pow of the target substance can be estimated as the average between the three obtained predictions, resulting as log Pow = 1.43.