3-amino-2,4,6-triiodobenzoic acid

Water solubility

Administrative data

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

17 Jan 2002 and 19 Feb 2002

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

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

GLP compliance:

yes

Type of method:

flask method

Test material

Test material information

Constituent 1

Reference substance name:

3-amino-2,4,6-triiodobenzoic acid

EC Number:

221-493-0

EC Name:

3-amino-2,4,6-triiodobenzoic acid

Cas Number:

3119-15-1

Molecular formula:

C7H4I3NO2

IUPAC Name:

3-amino-2,4,6-triiodobenzoic acid

Test material form:

solid: bulk

Results and discussion

Water solubility

Key result

Water solubility:

> 0.435 - < 0.453 g/L

Conc. based on:

test mat.

Loading of aqueous phase:

0.01 g/L

Incubation duration:

< 7 d

Temp.:

20 °C

pH:

ca. 3.13

Remarks on result:

other: standard deviation

Remarks:

0.008 g/L

Any other information on results incl. tables

The water solubility of the test item was determined using the flask method which is based on a suspending of the test substance in the solvent until saturation is reached, followed by separation of the saturated solution from the insoluble residues. The concentration was monitored by HPLC analysis. The results are given in the following table:

 

Table 1: Water solubility of the test item

t (days)	S 20°C (g/L) experiment A	S 20°C (g/L) experiment B
3	0.4975*	0.4782*
4	0.4445	0.4272
6	0.4471	0.4483
7	0.4474	0.4488

 

t: sampling time, time from start of the experiment at 20°C

S20°C-exp.A / S20°C-exp.B: raw data of the experiment A and B (duplicate)

* equilibrium not reached, therefore not taken for the calculation of the mean value

 

Averaging the actual concentrations of series of experiments after equilibration gives the following solubility of the test item with 95 % confidence interval:S20°C = 0.444 g/L ± 0.009 g/L.

 

Standard deviation: s = 0.008 g/L

The pH value of the aqueous solution was determined to be 3.13.

 

The investigation of the insoluble residue by HPLC showed no increase of decomposition products. According to X-ray powder diffraction the starting material and the insoluble residue consist of the same solid state form (see attatchment).

Applicant's summary and conclusion

Conclusions:

The mean measured water solubility of the test substance by HPLC was S20°C = 0.444 g/L ± 0.009 g/L (pH = 3.13).

Executive summary:

The water solubility of the test item was determined using the flask method. The following solubility with 95 % confidence interval of the substance in saturated solution was obtained after equilibration at 20°C and separation from the insoluble residues : S20°C = 0.444 g/L ± 0.009 g/L.The pH value of the aqueous solution was determined to be 3.13. The test item can be considered as very slightly soluble in accordance with the descriptive term of Ph.Eur., 3rd Edition and USP 24. According X-ray powder diffraction the starting material (batch 60708021) consist of the same solid state form as the insoluble residue.