Carnosine

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

22 - 29 May 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

1995

GLP compliance:

yes (incl. QA statement)

Remarks:

Swiss Federal Office of Public Health, Bern, Switzerland

Type of method:

flask method

Key result

Water solubility:

219 g/L

Temp.:

20 °C

pH:

ca. 8.4

Results and discussion

The results are given in the following table. The tabulated values represent rounded results, obtained by calculation using the exact raw data.

 

Sample No.	Shaking Time at 30 °C   [hours]	Measured Concentration in Injected Sample   [mg/L]	Dilution Factor	Determined Concentration in Water Sample   [g/L]	Water Solubility Mean Value   [g/L]	Overall Mean ± Std. Dev.   [g/L]	Rel. Std. Dev.   [%]
72-1 72-2	72 72	45.7 43.2	5000 5000	228 216	222	219 ± 4	1.9
48-1 48-2	48 48	45.1 43.2	5000 5000	225 216	221
24-1 24-2	24 24	42.8 *	5000 -	214	214

*Analytical error

 

The water solubility of the test item at 20 °C was found to be 219 ± 4 g/L.

 

According to the test guideline, the results for three assays should not differ by more than 15 %. The acceptance criterium was fulfilled. Thus, the study is valid.

 

The test item showed to be stable during the performance of the test.

 

The R² fit of the calibration curve used was 0.9928. This reflects the linearity of the analytical system within the calibration range of 21.6 to 107 mg test item / L.

 

The calibration was verified by a 2nd weighing of the test item and dilution of this stock solution into the calibration curve at levels of 40.7 and 81.0 mg/L. Analysis of these quality control solutions and evaluation against the calibration curve yielded recoveries of 104 % and 94 % compared to the nominal values. These data show the correct preparation of the calibration standards.

 

Conclusion

During this study, the water solubility of the test item was determined at 20 °C using the flask method.

The water solubility of the test item was found to be 219 ± 4 g/L at a mean pH value of 8.4.

Conclusions:

A water solubility of 219 ± 4 g/L at 20 °C, pH ca. 8.4 was determined for the test substance according to OECD Guideline 105.

Description of key information

Water solubility: 219 ± 4 g/L at 20 °C, pH ca. 8.4 (OECD Guideline 105, flask method)

Key value for chemical safety assessment

Water solubility:

219 g/L

at the temperature of:

20 °C