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 7 days at 70 °C and 100% relative humidity. |
Appearance of the substance
The substance, originally in the form of colourless crystals or a white, crystalline powder. changes after procedures A and B into deliquescent crystals.
Gain of moisture
Before exposure to heat and humidity: |
1% |
After procedure A: |
5% |
After procedure B: |
15% |
Chromatographic test
Adsorbent: Silica gel F-254
Solution applied to the plate: Substance dissolved in methanol.
Solvent system:
dioxan: ..............................15 volumes
ammonia 3 N: .....................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 sprayed with a solution containing 0.1% of triketohydrindene hydrate in acetone and heated at 100 °C for 3 minutes.
Results: The spots obtained from the solutions of each of the samples subjected to procedures A and B and the spots obtained from the reference solution of ephedrine sulfate display the same chromatographic characteristics of migration and detection. No secondary spots are revealed.
Ultraviolet spectrophotometry
The absorbances of ethanolic solutions are measured at about 253 nm, 259 nm and 275 nm.
After procedures A and B: no significant change.
Acidimetric determination
After extraction of the ephedrine base with chloroform in alkaline medium.
After procedures A and B: no change
Solubility
The rate of solubility of the samples subjected to procedures A and B is slower than for the untreated substance.
Conclusion
No chemical decomposition is detected, but the gain of moisture and the solubility change after procedures A and B indicate degradation.
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