Registration Dossier

Administrative data

Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Octobre 2019
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Remarks:
The study was conducted according to an internationally recognised method. No deviation was reported. Test substance is adequately specified. Therefore full validation applies

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2020
Report Date:
2020

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method)
Version / remarks:
Council Regulation (EC) No 2016/266 of 7. December 2015, Method A.24 “Partition Coefficient (n-
Octanol//Water), High Performance Liquid Chromatography (HPLC) Method
Deviations:
no
Qualifier:
according to
Guideline:
other: UE A.24
Version / remarks:
Council Regulation (EC) No 2016/266 of 7. December 2015, Method A.24 “Partition Coefficient (n-
Octanol//Water), High Performance Liquid Chromatography (HPLC) Method
Deviations:
no
GLP compliance:
no
Type of method:
HPLC method
Partition coefficient type:
octanol-water

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Details on test material:
- Appearance: Yellow powder
- Storage In darkness at room temperature
- Batch: 19246
- Manufacturing date: September 2019
- Expiry date: September 2021

Study design

Analytical method:
high-performance liquid chromatography

Results and discussion

Partition coefficient
Key result
Type:
log Pow
Partition coefficient:
< 0.3
Temp.:
20 °C
pH:
ca. 5
Details on results:
Due to the nature of the tests item which is an UVCB (substances of Unknown or Variable composition, Complex reaction products or Biological materials), a peak is measured between 1.35 and 1.84 minutes.
As the retention of the beginning of the peak was lower than the dead time and the retention time of the peak apex was equal to the dead time, the value of Log Pow was determined by using the regression equation on the Log k found thanks to the retention time of the end of the peak. If we consider that the linearity of calibration curve is still valid outside of the concentrations range used for calibration, the calculated < -0.51.
Even if the correlation coefficient r = 0.9862 is good, all measurements were lower than the retention time of the reference substance with the lowest partition coefficient (0.3) i.e.
2-butanone.
So, the partition coefficient n-octanol/water of the tests item is stated as lower than 0.3.

Applicant's summary and conclusion

Conclusions:
According to OECD method No. 117 and EU A.24, the partition coefficient n-octanol/water (Log Pow) of the test item is stated as lower than 0.3
Executive summary:

A non-GLP study was conducted according to OECD 117 and EU. A.24 to determine the partition coefficient of the test item.

The study was performed using an HPLC/RI detector with a C18 column. Seven reference items with different retention times and uracil, for the determination of the dead time, were used to establish a calibration curve.

This calibration curve, log k versus log Pow, was obtained from the known Log Pow values (between 0.3 and 4) of the reference items as reported in the OECD117/EU-method A.24 and the capacity factor k, calculated from the retention time of the respective reference items and uracil. The calibration curve was validated considering the correlation coefficient higher than 0.9. All measurements showed that the substance was eluted at a retention time lower than the retention time of the reference substance with the lowest partition coefficient (0.3), i.e. 2-butanone. So, according to the OECD method 117/EU A.24, the partition coefficient n-octanol/water of the test item was stated as lower than 0.3.