Pregnenolone

Surface tension

Administrative data

Endpoint:

surface tension

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because water solubility is below 1 mg/L at 20°C

Cross-reference

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

10 November 2017 - 13 December 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Version / remarks:

2016

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7840 (Water Solubility)

Version / remarks:

1998

Deviations:

no

GLP compliance:

yes

Type of method:

column elution method

Key result

Water solubility:

0.344 mg/L

Conc. based on:

test mat.

Temp.:

20 °C

pH:

>= 7.7 - <= 8

Remarks on result:

other: average of two runs

Details on results:

Mean concentration in the water samples (n=10) obtained at the flowrate of 24 mL/h was 0.346 mg/L. CV= 1.3%.
Mean concentration in the water samples (n=10) obtained at the flowrate of 12 mL/h was 0.342 mg/L. CV= 2.1%.
The maximum difference on the mean values at both flow rates was ≤ 30% (i.e. 1.2%). Average of two runs: 0.344 mg/L.

The coefficient of variation (CV) (n=10) was ≤ 30% at both flow rates. It demonstrated that the system was in equilibrium at all flow rates.

Small responses at the retention time of the test item were detected in the chromatograms of the samples from the blank column taken at a flow rate of 12 and 24 mL/h. The maximum contribution to the mean analyzed concentration of the samples was 13 % (24 mL/h) and 17% (12 mL/h). It was considered that it has no significant effect on the results of the test samples.

.

Conclusions:

The water solubility at 20°C was determined to be 0.344 mg/L.

Executive summary:

The water solubility of the substance was determined using the column elution method in a GLP study according to EC A.6, OECD 105 and OPPTS 830.7840.

Quantification was performed by HPLC. The water solubility was calculated as the average of two runs (24 mL/h and 12 mL/h).

The water solubility at 20°C was determined to be 0.344 mg/L. The pH of the fractions obtained at 12 ml/h and 24 ml/h was 7.7 and 8.0.