N-(N6-trifluoroacetyl-L-lysyl)-L-proline

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1993-03-22 to 1993-07-30

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Version / remarks:

1984

GLP compliance:

yes

Type of method:

flask method

Key result

Water solubility:

> 3.5 other: kg/L

Temp.:

20 °C

pH:

6.6

First addition of the test substance
Flask No.	Additional amount [g]	total Amount [g]	total V (water) [mL]	Concentration [g/L]
1	9.810	19.8076	10.0	1980.8
2	10.7816	21.1248	10.0	2112.5
3	8.6787	19.4638	10.0	1946.4

Second addition of the test substance (additional 4 mL of water)
Flask No.	Additional amount [g]	total Amount [g]	total V (water) [mL]	Concentration [g/L]
1	16.0892	35.8968	14.0	2564.1
2	13.6584	34.7832	14.0	2484.5
3	14.1563	33.6201	14.0	2401.4

Third addition of the test substance
Flask No.	Additional amount [g]	total Amount [g]	total V (water) [mL]	Concentration [g/L]
1	5.1384	41.0352	14.0	2931.1
2	4.9386	39.7218	14.0	2838.3
3	4.9104	38.5305	14.0	2752.2

Fourth addition of the test substance
Flask No.	Additional amount [g]	total Amount [g]	total V (water) [mL]	Concentration [g/L]
1	8.5439	49.5791	14.0	3541.4
2	8.2576	47.9794	14.0	3427.1
3	7.9742	46.5047	14.0	3321.8

By reason of the high viscosity of the solutions a more powerfull stirrer had to be used after the third addition of test substance. Therefore the solutions were transfered into 100 mL Erlenmeyer-flasks. And again after about one hour the test substance was totally dissolved. The fourth additional amount of test substance caused, that no thorough mixing was practicable. For further preparations on next day the solutions were stored in the refrigerator (approx. 6°C).

But on next day the solutions were clear again. Further substance amounts weren't ingenious for the following reasons:

- the highest water solubility already was 3.5 kg/L

- the high viscosity of the solutions prevent a thorough mixing

- in case of full saturation of the solutions a separation

of the solid would be impossible. Because of the above listed reasons the performance was stopped.

Conclusions:

It was impossible to determine the exact water solubilty of ε-Trifluoroacetyl-L-lysyl-L-proline in a test conducted according to EU Method A.6 (1984) so the true value must be higher than the most concentrated solution produced. This solution was also clear at a temperature of 6 °C (refrigerator).Therefore it can be said:
Water Solubility (ε-Trifluoroacctyl-L-lysyl-I-proline, 20°C) > 3-5 kg/L. The pH-value of this solution was: 6.6

Description of key information

> 3.5 kg/L at 20.0 °C. The pH of the aqueous sample was 6.6 (EEC method A.6., flask method, GLP).

Additional information

It was impossible to determine the exact water solubilty of ε-Trifluoroacetyl-L-lysyl-L-proline in a test conducted according to Directive 84/449/EEC, A.6 (1984) so the true value must be higher than the most concentrated solution produced. This solution was also clear at a temperature of 6 °C (refrigerator).

Therefore it can be said:

Water Solubility (ε-Trifluoroacctyl-L-lysyl-I-proline, 20 °C) > 3.5 kg/L. The pH-value of this solution was: 6.6.