Registration Dossier

Diss Factsheets

Administrative data

Endpoint:
water solubility
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
the study does not need to be conducted because the substance is hydrolytically unstable at pH 4, 7 and 9 (half-life less than 12 hours)
Justification for type of information:
The stability of the test item in aqueous media (demineralized water, Hydrolysis Buffer Solutions pH 4, pH 7, pH 9, Algal, and Daphnia test medium) was determined by measuring the concentration of the test item and its degradation products over time, using a validated HPLC method.
Due to the poor solubility of the test item, the medium / acetonitrile ratio must be 50 / 50 % (v/v).
The stability was determined by measuring a standard solution containing 50 mg/L :
- in demineralized water, Hydrolysis Buffer Solutions pH 4, pH 7, pH 9 at the time levels 0 h, 0.5 h, 4 h and 24 h, stored in closed bottles at room temperature (24.2 – 25.8 °C).
- in algal test medium at the time levels 0 h, 24 h and 72 h, stored in glass beakers covered with perforated plastic wrap at 21 – 23.3 °C.
- in daphnia test medium at the time levels 0 h, 24 h and 48 h, stored in glass beakers covered with perforated plastic wrap at 22.2 ± 23.5 °C.
The standard in all media showed insufficient stability. After 4 hours at the latest, more than half of the initial concentration of the test item had decomposed. Only in the hydrolysis buffer pH 9 and in the algal test medium a low signal (concentration < LOQ) of the test item could be detected after 24 h.
For the medias demineralized water and hydrolysis buffer pH 9 the half-life t1/2 was calculated:
t1/2 (demin. H2O; 25 °C) = 1.2 ± 0.7 h

t1/2 (hydrolysis buffer solution pH 9; 25 °C) = 3.1 ± 0.2 h

As a consequence, and in accordance with the column 2 of the annex VII of REACh regulation, the study does not need to be conducted, as the substance is hydrolytically unstable at pH 4, 7 and 9 (half-life less than 12 hours).
Cross-reference
Reason / purpose for cross-reference:
data waiving: supporting information
Reference
Endpoint:
other: Half-life in various aqueous media
Type of information:
experimental study
Adequacy of study:
key study
Study period:
From 03/09/2018 to 06/09/2018
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
comparable to guideline study
Principles of method if other than guideline:
The stability of the test item in aqueous media was determined by measuring the test item and its degradation products concentration over time, using a validated HPLC method.
GLP compliance:
yes (incl. QA statement)
Results:
The standard in all media showed insufficient stability. After 4 hours at the latest, more than half of the initial concentration of the test item had decomposed. Only in the hydrolysis buffer pH 9 and in the alga test medium a low signal (concentration < LOQ) of the test item could be detected after 24 h.
To perform a half-life calculation, at least 3 measured values are required, therefore only the half-life of the test item in the media demineralized water and hydrolysis buffer solution pH 9 can be calculated.
The half life of the test item was determined considering a first order kinetics.

The calculated half-life of the test item in demineralized water is:
t1/2 (demin. H2O; 25 °C) = 1.2 ± 0.7 h

The calculated half-life of the test item in hydrolyse buffer pH 9 is:
t1/2 (demin. H2O; 25 °C) = 3.1 ± 0.2 h

RESULTS

Stability in demineralized water

Nominal
Concentration
[mg/L]

Dilution
factor

Peak
Area
[mAU*min]

Concen-
tration
[mg/L]

Mean
Concentration
[mg/L]

Stability
[%]

50
t = 0 h

none

6.2270

39.18

36.58

100

5.9970

37.76

5.6509

35.62

5.3531

33.78

50
t = 0.5 h

none

4.2755

27.12

25.83

70.6

4.1483

26.33

3.9402

25.05

3.9038

24.82

50
t =4 h

none

1.5530

10.29

9.58

26.2

1.5415

10.22

1.3235

8.88

1.3297

8.91

50
t = 24 h

none

n.a.

n.a.

n.a.

0.0

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

 

The test item showed a very low stability in demineralized water. In addition to the decomposition of the test item, degradation products (DP) could be detected. The following table reports the retention times and the relative areas at the corresponding points in time of the test item and the degradation products.

Sample
point
[h]

Test item [%]

DP 1
[%]

DP 2
[%]

DP 3
[%]

DP 4
[%]

DP 5
[%]

DP 6
[%]

Retention
time
[min]

1.92

0.77

0.99

1.26

0.56

1.04

1.39

0

94.74

n.a

5.26

n.a

n.a

n.a

n.a

0.5

89.46

n.a

10.54

n.a

n.a

n.a

n.a

4

54.92

4.85

37.32

2.91

n.a

n.a

n.a

24

n.a

9.82

32.03

11.54

18.85

24.04

3.73

 

Stability in hydrolysis buffer solution pH 4

The test item immediately decomposed with the addition of the hydrolysis buffer solution pH 4. No signal of the test object could be detected in the chromatogram, only degradation products (DP) could be detected. The following table reports the retention times and the relative areas at the corresponding points in time of the degradation products.

Sample
point
[h]

Test item [%]

DP 1
[%]

DP 2
[%]

DP 3
[%]

DP 4
[%]

Retention
time
[min]

 

0.78

0.99

1.26

0.58

0

n.a

12.34

87.66

n.a

n.a

0.5

n.a

12.97

87.03

n.a

n.a

4

n.a

11.81

81.41

6.09

n.a

24

n.a

9.78

67.95

13.35

8.92

 

Stability in hydrolysis buffer solution pH 7

The test item immediately decomposed with the addition of the hydrolysis buffer solution pH 7. No signal of the test object could be detected in the chromatogram, only degradation products (DP) could be detected. The following table reports the retention times and the relative areas at the corresponding points in time of the degradation products.

Sample
point
[h]

Test item [%]

DP 1
[%]

DP 2
[%]

DP 3
[%]

DP 4
[%]

Retention
time
[min]

 

0.78

0.99

1.39

0.56

0

n.a

12.10

87.90

n.a

n.a

0.5

n.a

12.91

87.09

n.a

n.a

4

n.a

10.60

81.41

8.00

n.a

24

n.a

7.75

57.03

13.21

22.01

 

Stability in hydrolysis buffer solution pH 9

Nominal
Concentration
[mg/L]

Dilution
factor

Peak
Area
[mAU*min]

Concen-
tration
[mg/L]

Mean
Concentration
[mg/L]

Stability
[%]

50
t = 0 h

none

7.5369

47.28

46.69

100

7.6106

47.73

7.1660

44.98

7.3281

45.99

50
t = 0.5 h

none

6.7903

42.66

41.76

89.8

6.7398

42.35

6.4459

40.53

6.5996

41.48

50
t =4 h

none

2.8297

18.18

18.01

38.7

2.8882

18.55

2.7213

17.51

2.7640

17.78

50
t = 24 h

none

n.a.

0.00

< LOQ

0.0

n.a.

0.00

0.5887

< LOQ

0.5818

< LOQ

 

The test item showed a low stability in hydrolysis buffer solution pH 9. In addition to the decomposition of the test item, degradation products (DP) could be detected. The following table reports the retention times and the relative areas at the corresponding points in time of the test item and the degradation products.

Sample
point
[h]

Test item [%]

DP 1
[%]

DP 2
[%]

DP 3
[%]

DP 4
[%]

DP 5
[%]

Retention
time
[min]

1.92

0.75

1.00

1.21

0.56

1.04

0

99.12

n.a

0.88

n.a

n.a

n.a

0.5

97.46

n.a

2.54

n.a

n.a

n.a

4

64.49

3.06

26.68

5.77

n.a

n.a

24

9.29

8.54

n.a.

10.18

10.47

61.52

 

Stability in algal test medium

Nominal
Concentration
[mg/L]

Dilution
factor

Peak
Area
[mAU*min]

Concen-
tration
[mg/L]

Mean
Concentration
[mg/L]

Stability
[%]

50
t = 0 h

none

7.5662

47.46

44.26

100

7.3644

46.21

6.6201

41.61

6.6467

41.77

50
t = 24 h

none

0.0838

< LOQ

< LOQ

0.0

0.0847

< LOQ

0.0839

< LOQ

0.0818

< LOQ

50
t = 72 h

none

n.a.

n.a.

n.a.

0.0

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

 

The test item showed a low stability in algal test medium. In addition to the decomposition of the test item, degradation products (DP) could be detected. The following table reports the retention times and the relative areas at the corresponding points in time of the test item and the degradation products.

 

Sample
point
[h]

Test item [%]

DP 1
[%]

DP 2
[%]

DP 3
[%]

DP 4
[%]

DP 5
[%]

DP 6
[%]

Retention
time
[min]

1.92

0.70

0.95

1.26

0.53

1.04

1.39

0

77.52

19.49

2.63

n.a

0.35

n.a

n.a

24

2.24

45.34

21.81

15.03

11.17

n.a

4.41

72

n.a

30.14

10.32

18.50

28.70

4.00

5.32

 

Stability in daphnia test medium

Nominal
Concentration
[mg/L]

Dilution
factor

Peak
Area
[mAU*min]

Concen-
tration
[mg/L]

Mean
Concentration
[mg/L]

Stability
[%]

50
t = 0 h

none

7.2693

45.62

44.21

100

7.1750

45.04

6.9313

43.53

6.7850

42.63

50
t = 24 h

none

n.a.

n.a.

n.a.

0.0

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

50
t = 48 h

none

n.a.

n.a.

n.a.

0.0

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

 

The test item showed a very low stability in algal test medium. In addition to the decomposition of the test item, degradation products (DP) could be detected. The following table reports the retention times and the relative areas at the corresponding points in time of the test item and the degradation products.

Sample
point
[h]

Test item [%]

DP 1
[%]

DP 2
[%]

DP 3
[%]

Retention
time
[min]

1.93

0.70

0.96

1.21

0

77.20

20.04

2.76

n.a

24

n.a

51.20

36.09

12.72

48

n.a

45.22

43.50

11.28

 

Assessment of stability

The standard in all media showed insufficient stability. After 4 hours at the latest, more than half of the initial concentration of the test item had decomposed. Only in the hydrolysis buffer pH 9 and in the alga test medium a low signal (concentration < LOQ) of the test item could be detected after 24 h.

To perform a half-life calculation, at least 3 measured values are required, therefore only the half-life of the test item in the media demineralized water and hydrolysis buffer solution pH 9 can be calculated.

The half life of the test item was determined considering a first order kinetics.

 

The calculated half-life of the test item in demineralized water is:

t1/2(demin. H2O; 25 °C) = 1.2 ± 0.7 h

 

The calculated half-life of the test item inhydrolyse buffer pH 9is:

t1/2(demin. H2O; 25 °C) = 3.1 ± 0.2 h

Conclusions:
The standard in all media showed insufficient stability. After 4 hours at the latest, more than half of the initial concentration of the test item had decomposed. Only in the hydrolysis buffer pH 9 and in the algal test medium a low signal (concentration < LOQ) of the test item could be detected after 24 h.
For the medias demineralised water and hydrolyse buffer pH 9 the half-life t1/2 was calculated:
t1/2 (demin. H2O; 25 °C) = 1.2 ± 0.7 h

t1/2 (hydrolyse buffer solution pH 9; 25 °C) = 3.1 ± 0.2 h

No observations arousing doubts concerning the accuracy of the results and the validity of the study were made.
Executive summary:

The stability of the test item in aqueous media (demineralized water, Hydrolysis Buffer Solutions pH 4, pH 7, pH 9, Algal, and Daphnia test medium) was determined by measuring the concentration of the test item and its degradation products over time, using a validated HPLC method.

Due to the poor solubility of the test item, the medium / acetonitrile ratio must be 50 / 50 % (v/v).

The stability was determined by measuring a standard solution containing 50 mg/L :

-       in demineralized water, Hydrolysis Buffer Solutions pH 4, pH 7, pH 9 at the time levels 0 h, 0.5 h, 4 h and 24 h, stored in closed bottles at room temperature (24.2 – 25.8 °C).

-       in algal test medium at the time levels 0 h, 24 h and 72 h, stored in glass beakers covered with perforated plastic wrap at 21 – 23.3 °C.

-       in daphnia test medium at the time levels 0 h, 24 h and 48 h, stored in glass beakers covered with perforated plastic wrap at 22.2 ± 23.5 °C.

The standard in all media showed insufficient stability. After 4 hours at the latest, more than half of the initial concentration of the test item had decomposed. Only in the hydrolysis buffer pH 9 and in the algal test medium a low signal (concentration < LOQ) of the test item could be detected after 24 h.

For the medias demineralized water and hydrolysis buffer pH 9 the half-life t1/2 was calculated:       

t1/2(demin. H2O; 25 °C) = 1.2 ± 0.7 h

 

t1/2(hydrolysis buffer solution pH 9; 25 °C) = 3.1 ± 0.2 h

 

No observations arousing doubts concerning the accuracy of the results and the validity of the study were made.

Data source

Materials and methods

Results and discussion

Applicant's summary and conclusion