3-acetoxymethylen-7-amino-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

July 26, 2012 to November 26, 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study (OECD107) with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 107 (Partition Coefficient (n-octanol / water), Shake Flask Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient)

Deviations:

no

GLP compliance:

no

Type of method:

shake-flask method to: flask method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Key result

Type:

log Pow

Partition coefficient:

< -3.4

Temp.:

20 °C

pH:

ca. 4

Details on results:

The measurements of the Octanol phases produced a signal of the test item in the HPLC, which is not as clear as in the aqueous phases. Due to the presence of Octanol, the peak of the test item is overlaid by another signal, which was not observed in the aqueous phases or in the calibration. Although the integration of the test item signal for the Octanol phases is more conservative and should lead to higher concentrations, the concentrations of the tests 1a to 2b were below the lowest reasonable calibration standard with a concentration of 0.054275 mg/L.

Table 4 shows the results of the main test for the determination of the partition coefficient.

The values represented in the table are rounded values. The calculation was carried out with the original not rounded values.

Table 4: Main test for the determination of the partition coefficient

Test	1a	1b	2a	2b	3a	3b
c (aqueous phases) [mg/L] (measured values)	131.13 / 131.03	131.97 / 130.94	84.70 / 84.54	83.58 / 83.45	262.25 / 261.76	257.66 / 257.41
c (aqueous phases, mean values) [mg/L]	131.09	131.46	84.62	83.52	262.01	257.54
pH value of aq. phases (24°C)	4.3	4.1	4.1	4.1	3.8	3.8
c (n-Octanol phases) [mg/L] (measured values)	<0.05 / <0.05	<0.05 / <0.05	<0.05 / <0.05	<0.05 / <0.05	0.08 / 0.08	0.08 / 0.08
c (n-Octanol phases, mean values) [mg/L]	<0.05	<0.05	<0.05	<0.05	0.08	0.08
Total recovery rate of the test item [%]	88	89	86	84	88	87
POW	<0.0004	<0.0004	<0.0006	<0.0006	0.0003	0.003
log POW	<-3.4	<-3.4	<-3.2	<-3.2	-3.5	-3.5
Mean value log POW	<-3.4

Conclusions:

log Pow < -3.4
Pow < 0.0004

Executive summary:

The partition coefficient at 20 °C of test item 7-Aminocephalosporanic acid was determined by the shake flask method, according to OECD Test Guideline 107 and EC No. 440/2008 Part A. Method A.8.

log Pow < -3.4

Pow < 0.0004

Description of key information

log Pow < -3.4

Pow < 0.0004

Key value for chemical safety assessment

Log Kow (Log Pow):

-3.4

at the temperature of:

20 °C

Additional information

The log Pow is not -3.4, as one is forced to enter in the field above, but the log Pow is <-3.4.