Disodium {sulfonylbis[4,1-phenylenediazene-2,1-diyl(1-ethyl-6-hydroxy-4-methyl-2-oxo-1,2-dihydropyridine-5,3-diyl)]}dimethanesulfonate

Partition coefficient

Administrative data

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

12-Oct-2010 to 04-Mar-2011

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results. The study report was conclusive, done to a valid guideline and the study was conducted under GLP conditions.

Cross-reference

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2011

Report date:

2011

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

shake-flask method to: flask method

Partition coefficient type:

octanol-water

Test material

Test material information

Constituent 1

Reference substance name:

Acid Yellow RN 2903

IUPAC Name:

Acid Yellow RN 2903

Details on test material:

Identification: Acid Yellow RN 2903
Batch Number: Vers. Kilo 6, 26.05.2009
Purity: 65.7 %
Expiry Date: August 01, 2015
Storage Conditions: At room temperature at about 20 °C

Study design

Analytical method:

high-performance liquid chromatography

Results and discussion

Partition coefficient

Type:

log Pow

Partition coefficient:

< -3.4

Temp.:

22 °C

pH:

7.9

Any other information on results incl. tables

Neither the HPLC-method according to OECD Guideline No. 117 nor the flask-shaking method according to OECD Guideline No. 107 were applicable for the determination of the partition coefficient of Acid Yellow RN 2903. Thus, the log P_OW-value for the test item was estimated from its solubility in n-octanol and in water, respectively.

 

In the present study, the n-octanol solubility of Acid Yellow RN 2903 was determined to be < 2.501 µg/mL, which is below the concentration of the smallest calibration point (multiplied with the dilution factor). The water solubility was determined in the main test of Harlan Laboratories study D04382 and was found to be 6392.1 mg/L using the flask shaking method.

 

The tabulated values represent rounded results, which were obtained by calculation using the exact raw data.

 

A typical chromatogram of the smallest calibration point is given in the attached Figure 1. A typical chromatogram of a sample solution in n-octanol is given in the attached Figure 2. A typical HPLC chromatogram of a blank solution is shown in the attached Figure 3. An example of a calibration curve and the data for test item-standards is given in the attached Figure 4 and Table 2. The correlation coefficient r²was 0.9916 (optimum 1.0000). This reflects the linearity of the HPLC-system within the calibration range of 0.5002 µg/mL to 30.012 µg/mL of the test item.

 

The partition coefficient, log P_OW, of Acid Yellow RN 2903 was calculated from the individual solubilities in n-octanol and in water, respectively, to be:

 

log P_OW= log₁₀ (<2.501 mg/L / 6392.1 mg/L) = <-3.4

Table1       Results obtained for the Solubility of Acid Yellow RN 2903 in n-Octanol

Initial Weight of Test Item	n-Octanol added	Measured Concentration	Dilution Factor	Solubility in n-Octanol	Mean
[g]	[mL]	[mg/L]		[mg/L]	[mg/L]
0.10	10	< 0.5002	5	< 2.501	< 2.501
0.11	10	< 0.5002	5	< 2.501

 

 

 

Applicant's summary and conclusion

Conclusions:

The partition coefficient, log POW, of Acid Yellow RN 2903 was calculated from the individual solubilities in n-octanol and in water, respectively, to be log POW = <-3.4 at about 22 °C. The pH in the aqueous phase was 7.9.

Executive summary:

The determination of the partition coefficient log P_OWof Acid Yellow RN 2903 was performed using the flask shaking method as described in OECD guideline no. 117, “Preliminary estimate of the partition coefficient”.

 

Based on the results of the preliminary test, the partition coefficient, log P_OW, of Acid Yellow RN 2903 wasfoundto be below -2. Based on the individual solubilities in n‑octanol and in water, respectively, the log P_OWwas calculated to be:

 

log P_OW < -3.4 at about 22 °C

 

The pH in the aqueous phase was 7.9.