Potassium isobutyrate

Partition coefficient

Administrative data

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

02 Sept 2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Report date:

2019

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Test material

Test material information

Constituent 1

Reference substance name:

Potassium isobutyrate

EC Number:

243-077-8

EC Name:

Potassium isobutyrate

Cas Number:

19455-20-0

Molecular formula:

C4H8O2.K

IUPAC Name:

potassium 2-methylpropanoate

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: sponsor / 181101001
- Expiration date of the lot/batch: 31 Oct 2020
- Purity test date: 01 Nov 2018

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room Temperature (20 ± 5 °C); Keep away from humidity, keep under inert gas
- Stability under test conditions: Stable

Study design

Analytical method:

high-performance liquid chromatography

Results and discussion

Partition coefficient

Key result

Type:

log Pow

Partition coefficient:

-0.443

Temp.:

25 °C

pH:

5

Any other information on results incl. tables

Result and Validity

Result

As peak 1 showed a relative area about 100 %. it was considered as major peak.

Although area is not necessarily correlated to absolute concentration if a UV detector is used. it is assumed that the test item consists mainly of the peak 1. Using the correlation log k / log P_OW. the log P_OWof the major components of test itemPotassium isobutyratewas calculated as -0.443 ± 0.043 (mean ± standard deviation).

 

Validity

The validity criteria and results are presented in the following table:

Table. Validity Criteria and Results

Peak	Parameter	Criterion	Found	Assessment
1	Range (Max – Min. log POW)	< 0.1	0.086	valid
	Value within Range of Ref. Items	1.833 – 7.154	1.566	not valid

 

Discussion

Variations in the retention times of reference items and test item are very small. Therefore a stable configuration of the HPLC-column can be assumed.

The correlation log k/log P_OW is good: the coefficient of determination r²was calculated with 0.9568. This value was considered as sufficiently high to use the calibration function for the determination of the log P_OW of the test itemPotassium isobutyrate.

The test item peak lies before the reference item with the lowest log P_OW, 2- butanone. Therefore, the corresponding log P_OW should be stated as < 0.3. It is thus concluded that the test itemPotassium isobutyratehas a log P_OW of < 0.3. Using extrapolation, thelog P_OW of the test itemPotassium isobutyratelies about – 0.443 ± 0.043.

Although area is not necessarily correlated to the absolute concentration, if a UV detector is used, it is assumed that the test item consists mainly of one peak.

No observations were made which might cause doubts concerning the validity of the study outcome.

Applicant's summary and conclusion

Conclusions:

Using the correlation log k / log POW. the log POW of the major components of test item Potassium isobutyrate was calculated as -0.443 ± 0.043 (mean ± standard deviation).