Accelerated Degradation Experiment
Conditions
Procedure A: |
30 days exposure at 50 °C and 100% relative humidity. |
Procedure B: |
30 days exposure at 50 °C and 100% relative humidity followed by 8 days at 70 °C and 100% relative humidity |
Appearance of the substance
The substance, originally in the form of colourless crystals or a white or almost white, crystalline and odourless powder, separates after procedure A into an upper phase, dark red-brown in colour, and a lower highly viscous phase, both having an odour resembling caramel. After procedure B both phases acquire a brownish black coloration.
Gain of moisture
After procedures A and B: 75%.
Chromatographic test
Adsorbent: Silica gel F-254
Solution applied to the plate: Substance dissolved in water.
Solvent system:
n-butanol: ............................6 volumes
acetic acid: ..........................2 volumes
water: ..................................2 volumes
Development conditions: The solvent is allowed to migrate until the front reaches a line 15 cm from the starting line.
Detection: The plate is left in a chromatographic chamber containing some iodine crystals until spots appear.
Results: The spot obtained from the solution of the sample subjected to procedure A and the spot obtained from the reference solution of ascorbic acid display the same chromatographic characteristics of migration and detection. After procedure B, degradation occurs.
Conclusion
No decomposition is detected by thin-layer chromatography after procedure A, but it is subject to severe decomposition after procedure B, as also seen from the change in the appearance of the substance and the gain of moisture.
Loading...
