Sodium 3-amino-2,4,6-triiodobernzoate

Partition coefficient

Administrative data

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

not reported

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Report date:

2002

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

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

Version / remarks:

Guideline 107 is not specifically stated but Shake Flask method is referenced in the study report.

Deviations:

no

Principles of method if other than guideline:

Information on the n-octanol/water partition coefficient of the test substance was to be obtained as a contribution to the Schering project “Ecotoxicological Evaluation of Starting Materials, Intermediates and Drug Substances”. The project is part of the “Freiwillige Selbstverpflichtung der deutschen chemischen Industrie für die Erfassung und Bewertung von Stoffen” (voluntary self commitment of the German chemical industry to catalogue and evaluate chemicals) as promoted by the VCI (Verband der Chemischen Industrie).

The guidance provided by the VCI (Ref. 1) calls for valid data with respect to the aim of the project, namely to gain information on the behavior or the persistence and fate of such compounds in the environment. Within the scope of the project conclusions are acceptable as drawn on basis of analogies to similar compounds or as derived from knowledge regarding the behavior of chemical structures and functional groups.

GLP compliance:

not specified

Type of method:

flask method

Partition coefficient type:

octanol-water

Test material

Test material information

Constituent 1

Reference substance name:

Sodium 3-amino-2,4,6-triiodobernzoate

EC Number:

614-015-0

Cas Number:

67031-56-5

Molecular formula:

C7-H3-I3-N-O2.Na

IUPAC Name:

Sodium 3-amino-2,4,6-triiodobernzoate

Test material form:

solid: bulk

Results and discussion

Partition coefficient

Partition coefficient 1

Key result

Type:

log Pow

Partition coefficient:

3.3

Temp.:

25 °C

pH:

ca. 1

Partition coefficient 2

Key result

Type:

log Pow

Partition coefficient:

0.97

Temp.:

25 °C

pH:

ca. 4

Partition coefficient 3

Key result

Type:

log Pow

Partition coefficient:

> 0.105 - < 0.111

Temp.:

25 °C

pH:

ca. 7

Partition coefficient 4

Key result

Type:

log Pow

Partition coefficient:

-1.42

Temp.:

25 °C

pH:

ca. 9

Any other information on results incl. tables

Please see attatchment.

Applicant's summary and conclusion

Conclusions:

The n-octanol/water partition coefficient was calculated (0.1 M HCl and 25 degree C) to be log Pow 3.30 at pH= 1, log Pow 0.97 at pH= 4, log Pow - 0.97 at pH= 7, and log Pow - 1.42 at pH= 9.

Executive summary:

The pH dependence of the n-octanol/water partition coefficient of the free acid of the test substance was determined with the flask-shaking method (see report A04323 (ADP 2001_091)) to be:

 

pH	mean Powwith standard deviations	log Pow	95 % confidence intervals for log Pow
1*	1984 ± 33	3.30	3.29 to 3.31
4	9.3 ± 0.2	0.97	0.96 to 0.98
7	0.108 ± 0.003	- 0.97	- 0.98 to (- 0.96)
9	0.038 ± 0.001	- 1.42	- 1.43 to (- 1.41)

*0.1 M HCl

Due to the law of mass action, the ratio of neutral to protonated form(s) and thus also the n-octanol/water partition coefficient of a ionizable substance is only dependent on the pH value of the solution and not of the form applied. Therefore the above results are also valid for the sodium salt of the test substance.