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 4 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 yellowish white, crystalline powder with a slight and characteristic odour acquires gradually after procedures A and B a more pronounced colour and odour. It changes into a colourless to yellowish solution after procedure A and becomes bright yellow after procedure B.
Gain of moisture
After procedures A and B: |
168% |
Chromatographic test
Adsorbent: Silica gel F-254
Solution applied to the plate: Substance dissolved in water.
Solvent system:
n-butanol ............................... 50 volumes
ethane 95% .......................... 25 volumes
concentrated ammonia ........... 10 volumes
water ...................................... 25 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 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 thiamine hydrochloride display the same chromatographic characteristics of migration and detection. No secondary spots are revealed, but the main spot decreases in intensity.
Conclusion
No decomposition is detected by thin-layer chromatography, but the appearance of the substance changes after procedures A and B.
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