L-histidine monohydrochloride

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 2017-07-06 to 2017-07-14

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7840 (Water Solubility)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

TOXI-COOP ZRT., 8230 Balatonfüred, Arácsi út 97., Hungary

Type of method:

flask method

Key result

Water solubility:

149.55 g/L

Conc. based on:

test mat.

Incubation duration:

>= 24 - <= 72 h

Temp.:

20 °C

pH:

>= 4.38 - <= 4.48

Details on results:

Preliminary Test
The water solubility of the test item was estimated to be ca. 185 g/L in a preliminary test and therefore the shake-flask method was used in the main test.
Calibration
The calibration solutions were prepared in 1 – 50 μg/mL range. The calibration samples were analysed by HPLC-UV method with three replicate injections from each. Concentration of L-histidine monohydrochloride monohydrate was calculated with the help of the calibration equation.

Results of the determination of water solubility of L-histidine monohydrochloride monohydrate

Sampling time	Measured concentrationofTest Item (g/L )		Measured pH
	Test vessels	Mean
After 24h	147.72	148.21	4.41
	148.81		4.41
	148.11		4.40
After 48h	148.59	148.28	4.48
	146.92		4.48
	149.34		4.48
After 72h	149.92	152.16	4.38
	152.49		4.38
	154.06		4.38
Solubility ofthe test item (g/L) with the 95% confidence interval:		149.55 ± 5.61	-
RSD%:		2	-

 

Conclusions:

The water solubility of the test item was determined to be 149.55 ± 5.61 g/L (95% confidence interval) at 20 °C ± 0.5 °C using the shake-flask method. The result is also applicable for the water free form of the test item.

Executive summary:

The water solubility was determined according to OECD 105, Regulation (EC) No. 440/2008 method A.6 and OPPTS 830.7840 using the shake flask method with HPLC analysis. About 40 g test item were weighed into stoppered Erlenmeyer flasks (nine parallels) according to the estimated solubility based on the Preliminary Test. After the addition of 50 mL ultra-pure water, the flasks were agitated at 30 °C. After one day, three of the vessels were removed and re-equilibrated at 20 °C for 24 hours. The content of the vessel was then centrifuged at 20 °C and the concentration in the clear aqueous phase was determined by HPLC. The other flasks were treated similarly after initial equilibration at 30 °C for two and three days, respectively. The samples were diluted before the analysis (two parallel dilutions). The pH of each sample was recorded. The water solubility of the test substance was determined to be 149.55 ± 5.61 g/L (95 % confidence interval) at 20 °C ± 1 °C (pH 4.38 - 4.48). The result is also applicable for the water free form of the test item.

Description of key information

The water solubility of the test item was determined to be 149.55 ± 5.61 g/L (95% confidence interval) at 20 °C ± 0.5 °C using the shake-flask method. The result is also applicable for the water free form of the test item.

Key value for chemical safety assessment

Water solubility:

149.55 g/L

at the temperature of:

20 °C

Additional information

The water solubility was determined according to OECD 105, Regulation (EC) No. 440/2008 method A.6 and OPPTS 830.7840 using the shake flask method with HPLC analysis (reference 4.8-1). About 40 g test item were weighed into stoppered Erlenmeyer flasks (nine parallels) according to the estimated solubility based on the Preliminary Test. After the addition of 50 mL ultra-pure water, the flasks were agitated at 30 °C. After one day, three of the vessels were removed and re-equilibrated at 20 °C for 24 hours. The content of the vessel was then centrifuged at 20 °C and the concentration in the clear aqueous phase was determined by HPLC. The other flasks were treated similarly after initial equilibration at 30 °C for two and three days, respectively. The samples were diluted before the analysis (two parallel dilutions). The pH of each sample was recorded. The water solubility of the test substance was determined to be 149.55 ± 5.61 g/L (95 % confidence interval) at 20 °C ± 1 °C (pH 4.38 - 4.48). The result is also applicable for the water free form of the test item.