Registration Dossier

Administrative data

Endpoint:
hydrolysis
Type of information:
experimental study
Adequacy of study:
key study
Study period:
6 August - 20 September 2007
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study was conducted in GLP compliance and in accordance with an internationally established guideline (see below).

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2007
Report date:
2007

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)

Test material

Constituent 1
Chemical structure
Reference substance name:
-
EC Number:
485-140-4
EC Name:
-
Cas Number:
515815-48-2
Molecular formula:
C33 H30 N4 O2 x HCl
IUPAC Name:
4’-(2-Propyl-4-methyl-6-(1-methylbenzimidazolyl-2-yl)-benzimidazol-1-ylmethyl)biphenyl-2-carbonsäure Hydrochlorid
Details on test material:
- Name of test material (as cited in study report): BIBR 277 CL
- Molecular formula (if other than submission substance): C33H30N4O2*HCl
- Molecular weight (if other than submission substance): 514.6 + 36.5 g/mol
- Structural formula attached as image file (if other than submission substance): see reference substance
- Physical state: solid; sligh brownish
- Analytical purity: 99.8 %
- Purity test date: 26. march 2007
- Lot/batch No.: 10
- Expiration date of the lot/batch: 8. march 2008
- Storage condition of test material: at room temperature, dark and dry

Study design

Details on sampling:
Samples were taken after 41, 72, 121 and 168 hours. The samples were filtered before the analysis.
Buffers:
20 mM Sodiumhexylsulfonate, 50 mM potassium dihydrogenphosphate
3.76 g sodium hexylsulfonate and 6.80 g potassium dihydrogenphosphate were dissolved in water and the pH was set to 3 with the addition of phosphoric acid solution. The final volume was 1000 ml.
Details on test conditions:
The hydrolysis was examined at 4 pH at 50 +- 0.5°C and at 25 +- 0.5°C in the dark.
Sterile buffer solution was prepared:
pH 4.0: 5 ml 0.2 M Sodium hydroxide and 625 ml 0.2 M Potassium hydrogen phthalate was diluted 2500 ml with ultra-pure water. The pH of the buffer solution was checked with calibrated pH meter. The hydrolysis reaction was carried out using a dark thermostat to avoid photolytic effects. Nitrogen was bubbled into the water for five minutes before the preparation of the solution in order to exclude oxygen.
Statistical methods:
The chromatograms were evaluated with the help of 'LaChrom Chromatogram Processor'.
Calculation of the rate constant:
k = 2.303/t * log (Co/Ct)
Calculation of the half-life:
t1/2 = 0.693 / k

with t = time; Co = concentration at time 0; Ct = concentration at time t

Results and discussion

Preliminary study:
A preliminary study was carried out indicating that more than 10% of the test substance hydrolyse at pH 4, 50°C after 5 days (see LAB International_06/134-336AN)
Dissipation DT50 of parent compoundopen allclose all
pH:
4
Temp.:
25 °C
Hydrolysis rate constant:
0
DT50:
101 d
pH:
4
Temp.:
50 °C
Hydrolysis rate constant:
0
DT50:
85 d

Applicant's summary and conclusion

Conclusions:
A hydrolysis half life value of 101 d was determined at pH 4 at 25°C in a reliable study conducted according to an appropriate test protocol but not conducted according to GLP.