Accelerated Degradation Experiment
Conditions
Procedure A1: |
10 days exposure at 50 °C and 100% relative humidity. |
Procedure A2: |
20 days exposure at 50 °C and 100% relative humidity. |
Procedure A3: |
30 days exposure at 50 °C and 100% relative humidity. |
Procedure B: |
30 days exposure at 50 °C and 100% relative humidity followed by 5 days at 70 °C and 100% relative humidity. |
Appearance of the substance
The substance, originally in the form of a white or creamy white powder, changes after procedures A1, A2 and A3, into a turbid yellowish liquid that contains a white deposit. After procedure B a yellow turbid liquid with a very slight deposit can be observed.
Gain of moisture
Before exposure to heat and humidity: |
16% |
After procedure A3: |
69% |
After procedure B: |
63.5% |
Chromatographic test
Adsorbent: Silica gel G, thickness 0.25 mm.
Solution applied to the plate: Substance dissolved in water.
Solvent system:
ethane 95% .............................. 6 volumes
water ......................................... 2 volumes
concentrated ammonia ............... 2 volumes
Development conditions: The solvent is allowed to migrate until the front reaches a line 15 cm from the starting line.
Detection: After drying the plate at 70 °C, it is left in a chromatographic chamber containing some iodine crystals until spots appear.
Results: Only one spot is obtained from the reference solution of sodium calcium edetate, whereas from the solution of the samples subjected to procedure A2 a secondary more mobile spot is revealed.
pH value
Prepare a 5% solution of the substance in water.
Before exposure to heat and humidity: |
7.1 |
After procedure A1: |
6.67 |
After procedure A2: |
6.37 |
After procedure A3: |
6.22 |
After procedure B: |
5.95 |
Conclusion
Sodium calcium edetate is subject to decomposition under accelerated degradation conditions.
Loading...
