Diammonium 5-(hexylsulfonyl)-2-{[3-methyl-2,7-dioxo-1-(3-sulfonatobenzoyl)-2,7-dihydro-3H-naphtho[1,2,3-de]heterocycle-6-yl]amino}benzenesulfonate

Hydrolysis

Administrative data

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

08 January 2009 to 26 February 2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: 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 relevant results.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method C.7 (Degradation: Abiotic Degradation: Hydrolysis as a Function of pH)

GLP compliance:

yes (incl. QA statement)

Remarks:

Date of inspection: 19 August 2008; Date of signature: 04 March 2009

Test material

Test material information

Radiolabelling:

no

Study design

Analytical monitoring:

yes

Duration of test

Duration of test 1

Duration:

120 h

pH:

4

Temp.:

50 °C

Initial conc. measured:

0.515 g/L

Duration of test 2

Duration:

120 h

pH:

4

Temp.:

50 °C

Initial conc. measured:

0.514 g/L

Duration of test 3

Duration:

120 h

pH:

7

Temp.:

50 °C

Initial conc. measured:

0.511 g/L

Duration of test 4

Duration:

120 h

pH:

7

Temp.:

50 °C

Initial conc. measured:

0.513 g/L

Duration of test 5

Duration:

120 h

pH:

9

Temp.:

50 °C

Initial conc. measured:

0.502 g/L

Duration of test 6

Duration:

120 h

pH:

9

Temp.:

50 °C

Initial conc. measured:

0.501 g/L

Results and discussion

Transformation products:

not specified

Dissipation DT50 of parent compound

Dissipation DT50 of parent compound 1

pH:

4

Temp.:

25 °C

DT50:

> 1 yr

Dissipation DT50 of parent compound 2

pH:

7

Temp.:

25 °C

DT50:

> 1 yr

Dissipation DT50 of parent compound 3

pH:

9

Temp.:

25 °C

DT50:

> 1 yr

Any other information on results incl. tables

Preliminary test/Tier 1

The mean peak areas relating to the standard and sample solutions are shown in the following table:

Table 2

Solution	Mean peak area
Standard 487 mg/l	1.237 x 10^4
Standard 505 mg/l	1.291 x 10^4
Initial Sample A, pH 4	1.316 x 10^4
Initial Sample B, pH 4	1.317 x 10^4
Standard 563 mg/l	1.420 x 10^4
Standard 530 mg/l	1.341 x 10^4
69 Hour Sample A, pH 4	1.309 x 10^4
69 Hour Sample B, pH 4	1.309 x 10^4
Standard 568 mg/l	1.436 x 10^4
Standard 560 mg/l	1.436 x 10^4
120 Hour Sample A, pH 4	1.312 x 10^4
120 Hour Sample B, pH 4	1.308 x 10^4
Standard 578 mg/l	1.490 x 10^4
Standard 551 mg/l	1.420 x 10^4
Initial Sample A, pH 7	1.315 x 10^4
Initial Sample B, pH 7	1.319 x 10^4
Standard 493 mg/l	1.308 x 10^4
Standard 513 mg/l	1.331 x 10^4
69 Hour Sample A, pH 7	1.303 x 10^4
69 Hour Sample B, pH 7	1.299 x 10^4
Standard 554 mg/l	1.403 x 10^4
Standard 551 mg/l	1.419 x 10^4
120 Hour Sample A, pH 7	1.306 x 10^4
120 Hour Sample B, pH 7	1.310 x 10^4

Solution	Mean peak area
Standard 538 mg/l	1.377 x 10^4
Standard 542 mg/l	1.387 x 10^4
Initial Sample A, pH 9	1.361 x 10^4
Initial Sample B, pH 9	1.365 x 10^4
Standard 516 mg/l	1.261 x 10^4
Standard 524 mg/l	1.315 x 10^4
69 Hour Sample A, pH 9	1.284 x 10^4
69 Hour Sample B, pH 9	1.292 x 10^4
Standard 553 mg/l	1.417 x 10^4
Standard 532 mg/l	1.375 x 10^4
120 Hour Sample A, pH 9	1.291 x 10^4
120 Hour Sample B, pH 9	1.291 x 10^4

The test material concentrations at the given time points are shown in the following tables:

Table 3    pH 4 at 50.0 ± 0.5ºC

Time (Hours)	Concentration (g/l)		Log10[concentration (g/l)]		% of mean initial concentration
	A	B	A	B	A	B
0	0.517	0.517	-0.287	-0.286	99.9	100
69	0.518	0.518	-0.285	-0.285	100	100
120	0.515	0.514	-0.288	-0.289	99.7	99.4

Result:           Less than 10% hydrolysis after 5 days at 50°C, equivalent to a half-life greater than 1 year at 25°C.

Table 4    pH 7 at 50.0 ± 0.5ºC

Time (Hours)	Concentration (g/l)		Log10[concentration (g/l)]		% of mean initial concentration
	A	B	A	B	A	B
0	0.510	0.512	-0.292	-0.291	99.9	100
69	0.497	0.495	-0.304	-0.305	97.2	96.9
120	0.511	0.513	-0.291	-0.290	100	100

Result:           Less than 10% hydrolysis after 5 days at 50°C, equivalent to a half-life greater than 1 year at 25°C.

Table 5    pH 9 at 50.0 ± 0.5ºC

Time (Hours)	Concentration (g/l)		Log10[concentration (g/l)]		% of mean initial concentration
	A	B	A	B	A	B
0	0.532	0.533	-0.274	-0.273	99.8	100
69	0.518	0.522	-0.285	-0.283	97.4	98.0
120	0.502	0.501	-0.300	-0.300	94.3	94.2

Result:           Less than 10% hydrolysis after 5 days at 50°C, equivalent to a half-life greater than 1 year at 25°C.

 Validation

The linearity of the detector response with respect to concentration was assessed over the nominal concentration range of 0 to 1.00 x 10³ mg/l for each matrix. These were satisfactory with correlation coefficients of ≥ 0.999 being obtained.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The estimated half-lives at 25°C of the test material at pH 4, pH7 and pH9 was shown to be >1 year.

Executive summary:

Assessment of hydrolytic stability was carried out using Method C7 Abiotic Degradation, Hydrolysis as a Function of pH of Commission Regulation (EC) No 440/2008 of 30 May 2008.

The results are as follows:

pH	Estimated half-life at 25°C
4	>1 year
7	>1 year
9	>1 year