1,6-Naphthyridine-3-carboxamide, 4-(4-cyano-2-methoxyphenyl)-5-ethoxy-1,4-dihydro-2,8-dimethyl-

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method A.6 (Water Solubility)

GLP compliance:

no

Type of method:

flask method

Water solubility:

18.3 mg/L

Conc. based on:

test mat.

Temp.:

20 °C

pH:

6.4

Remarks on result:

other: mean pH-value

Details on results:

The relative standard deviation between the single determinations is < 15 %.
A solubility pretest indicated a solubility of approx. 19.8 mg/L. Therefore the test concentration for the main test was set to 100 mg/L and the flask method was chosen to determine the water solubility of Rac-Amido-TH-naphthyridine.

	Flask A	Flask B	Flask C	Mean value
conc. of test item after filtration [mg/L]	18.14934	16.856855	18.99980	18.0
conc. of test item after centrifugation [mg/L]	18.92266	17.55787	19.38737	18.6
pH-value	6.3	6.3	6.5	-

Conclusions:

The water solubility of Rac-Amido-TH-naphthyridin was determined as 18.3 mg/L at 20 °C.

Executive summary:

The water solubility of the test item Rac-Amido-TH-naphthyridin in demineralized water was determined with the flask method at 20 °C according to OECD TG 105.

For the main test, a quantity of the test item necessary for saturation is dissolved in demineralized water. The vessels are stoppered and stirred on a magnetic stirrer for 24 h, 48 h and 72 h at 30 °C in a temperature controlled water bath. Following this procedure, the temperature is reduced to 20 °C and is kept in the temperature controlled water bath for another 24 h.

Since the test item was also floating on the surface of the water and a complete separation by centrifugation could not be guaranteed, the samples were also filtrated with a disposable syringefilter, the concentration of the test item in the aqueous test solutions is determined by HPLC-analysis with UV-detection. The results of both sample treatments were used for determination of the water solubility.

The water solubility of Rac-Amido-TH-naphthyridin at 20 °C was determined as 18.3 mg/L.

Description of key information

The water solubility of Rac-Amido-TH-naphthyridin was determined as 18.3 mg/L at 20 °C.

Key value for chemical safety assessment

Water solubility:

18.3 mg/L

at the temperature of:

20 °C