Calcium glycinate (1:2)

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2020

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Test performance:

Hydrolysis of Calcium Diglycinate was conducted at 50±0.5°C in buffer pH 4, 7 and 9 buffer solutions for a period of 5 days.
Based on the test results Calcium Diglycinate was found hydrolytically stable in
buffer pH 4, 7 and 9 buffers at 50C ± 5ºC.
Hydrolysis samples were analysed by H-NMR on Day 0 and Day 5 to study the
hydrolysis process of test item and observed that; shift in the chemical shift or delta value of specific proton in amino acid moiety of Calcium Diglycinate
The H-NMR analysis on Day 0 and Day 5 in different pH showed slight shift in delta value for CH2 proton in different pH buffers (buffer pH 7.0 and buffer pH 9.0). There is no extra peak observed other than CH2. This shift could be due to molecular association in different pH. Hence the shift in delta value cannot be attributed to the hydrolysis of ligand. There was no changes observed in buffer pH 4.0 on day 0 and day 5.
Hydrolysis samples were analysed by ICP-MS on Day 0 and Day 5 at 50 ± 0.5°C to
determine the total calcium content in the test item. Results showed that the total Calcium content remains unchanged.
Sterility was checked on Day 0 and Day 5 for each of the test systems (a single
sample from each pH buffer solution). There was no microbial growth of total
bacterial count and total yeast and mould count were observed.

Transformation products:

no

pH:

9

Temp.:

50 °C

DT50:

> 1 yr

Type:

(pseudo-)first order (= half-life)

pH:

7

Temp.:

50 °C

DT50:

> 1 yr

Type:

(pseudo-)first order (= half-life)

pH:

4

Temp.:

50 °C

DT50:

> 1 yr

Type:

(pseudo-)first order (= half-life)

Validity criteria fulfilled:

yes

Conclusions:

On the basis of test results, the test item was not hydrolyzed in buffer
pH 4, pH 7 and pH 9 at 50 ± 0.5ºC for 5 days. The test item was considered as
hydrolytically stable in buffer pH 4, pH 7 and pH 9 buffers. It concludes that the test item half-life is greater than 1 year (t1/2 >1 Year) in buffer pH 4, pH 7 and pH 9.

Description of key information

On the basis of test results, the test item was not hydrolyzed in buffer
pH 4, pH 7 and pH 9 at 50 ± 0.5ºC for 5 days. The test item was considered as
hydrolytically stable in buffer pH 4, pH 7 and pH 9 buffers. It concludes that the test
item half-life is greater than 1 year (t1/2 >1 Year) in buffer pH 4, pH 7 and pH 9.

Key value for chemical safety assessment

Half-life for hydrolysis:

1 yr

at the temperature of:

50 °C