DL-thyroxin

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

February 18, 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Qualifier:

equivalent or similar to guideline

Guideline:

EPA OPPTS 830.7840 (Water Solubility)

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Specific details on test material used for the study:

Name: LEVOTHYROXINE ACID
Batch No.: B486066
Expiry date: 27 August 2020
Storage condition: at room temperature, protected from light
Appearance: white slightly creme, powder

Key result

Water solubility:

< 0 mg/L

Conc. based on:

test mat.

Incubation duration:

ca. 24 h

Temp.:

20 °C

pH:

ca. 7.7

Remarks on result:

other: below quantitation limit, calculated with LOQ value

Key result

Water solubility:

ca. 0 mg/L

Conc. based on:

test mat.

Incubation duration:

ca. 48 h

Temp.:

20 °C

pH:

ca. 8.3

Key result

Water solubility:

< 0 mg/L

Incubation duration:

ca. 72 h

Temp.:

20 °C

pH:

ca. 7.26

Details on results:

Solubility is below 10-2 g/l, so the column elution method should be applied according to the guideline. However column elution method is not feasible with this test item, because coating of the support material is not possible, due to the low solubility of the test item in any volatile solvent (hexane, dichloromethane, acetone, methanol). Therefore the flask method was applied.

Conclusions:

In conclusion the water solubility of LEVOTHYROXINE ACID was determined to be lower than 2.82 x 10-5 g/L at 20 ± 0.5 °C, using the shake-flask method for the performance.

The individual results were given for each of the three tests. Results did not show a tendency of increasing values and are deemed to be constant.

Executive summary:

In the course of this study thewater solubilityof LEVOTHYROXINE ACID was determinedusing the shake-flask method for the performance of the main test.

The water solubility was determined to belower than 2.82 x 10^-5g/L at 20 ± 0.5 °C.

 

Reference 2

Endpoint:

water solubility

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Study period:

2021

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a (Q)SAR model, with limited documentation / justification, but validity of model and reliability of prediction considered adequate based on a generally acknowledged source

Qualifier:

no guideline required

Principles of method if other than guideline:

The programme WSKOWWIN estimates the water solubility of an organic compound using the compounds log octanol-water partition coefficient.
The programme WATERNT estimates the water solubility of an organic compound. It requires only a chemical structure and is based upon a fragment constant method.

Specific details on test material used for the study:

SMILES used: SMILES : c1(I)c(Oc2cc(I)c(O)c(I)c2)c(I)cc(CC(N)C(=O)O)c1

Water solubility:

ca. 0 mg/L

Temp.:

25 °C

Conclusions:

Water Solubility Estimate from Log Kow (WSKOW v1.42):
Water Solubility at 25 deg C (mg/L): 0.0001047

Executive summary:

The water solubility of the substance was calculated by QSAR model WSKOWWIN to 0.0001047 mg/L at 25 °C.

Description of key information

In the course of this study thewater solubilityof LEVOTHYROXINE ACID was determinedusing the shake-flask method for the performance of the main test.

The water solubility was determined to belower than 2.82 x 10^-5g/L at 20 ± 0.5 °C.

The water solubility of the substance was calculated by QSAR model WSKOWWIN to 0.0001047 mg/L at 25 °C.

 

Key value for chemical safety assessment

Water solubility:

0 g/L

at the temperature of:

20 °C