Registration Dossier

Administrative data

Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Modern study peformed under GLP and using the recommended method, EU method A.8.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1994

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
EU Method A.8 (Partition Coefficient)
GLP compliance:
yes
Type of method:
shake-flask method to: flask method
Partition coefficient type:
octanol-water

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
The test material received from F. Hoffmann-La Roche Ltd was a white solid powder from lot no. 25927 with a purity of 99.8%.

Study design

Analytical method:
gas chromatography

Results and discussion

Partition coefficient
Type:
Pow
Partition coefficient:
121.07
Temp.:
25 °C
Details on results:
The partition coefficient of PTH-decahydroamide (Ro 31-9373/000) in octanol/water at 25 °C was determined to be Pow = 121.07 (log Pow = 2.07).

Any other information on results incl. tables

The table below shows the resuls for the partition coefficient of PTH-Decahydroamide in n-octanol/water at 25 ⁰C;

Test Sample

PTH

n-octanol (g/L)

PTH-

H2O total (g/L)

PTH

H2O neutral (g/L)

Partition coefficient Pow

logPow

pH of the aqueous layer

A1

1.87475

0.02058

0.01644

114.04

2.06

7.23

A2

1.84765

0.01777

0.01396

132.35

2.12

7.47

B1

2.04995

0.02685

0.02206

92.93

1.97

7.71

B2

2.02725

0.02887

0.02388

84.89

1.93

7.58

C1

1.99910

0.01646

0.01281

156.06

2.19

7.70

C2

1.99240

0.01739

0.01363

146.18

2.16

7.63

 

 

 

Average

121.08

2.07

7.55

 

 

 

Std. Dev.

28.75

0.10

0.18

 

 

 

Rel. Std. Deviation

23.7%

4.8%

2.4%

 

 

 

n

6

6

6

Averaging the values calculated from the 6 test experiments, the partition coefficient of PTH-decahydroamide (Ro 31-9373/000) in octanol/water at 25 °C was determined to be Pow= 121.07 (log Pow= 2.07). The log Pow values range from 1.93 to 2.19 which is within the range of ±0.3 log units allowed by the EEC guidelines A.8.

The recoveries of 93.6 -103.5% obtained for all the test experiments demonstrated the validity of the analytical method applied.

Applicant's summary and conclusion

Conclusions:
The partition coefficient of PTH-decahydroamide (Ro 31-9373/000) in octanol/water at 25 °C was determined to be Pow = 121.07 (log Pow = 2.07).
Executive summary:

The determination of the partition coefficient (n-octanol/water) of PTH-Decahydroamide (Ro 31 -9373/000) was performed using EC directive 92/69/EEC, method A.8 (1992),

The partition coefficient of PTH-decahydroamide (Ro 31-9373/000) in octanol/water at 25 °C was determined to be Pow = 121.07 (log Pow = 2.07).