Accelerated Degradation Experiment
Conditions
Procedure A: |
30 days exposure at 50 °C and 100% relative humidity. |
Appearance of the substance
The substance, originally in the form of a creamy white to light yellow powder, changes after procedure A into a dark brown liquid.
Gain of moisture
Before exposure to heat and humidity: |
6% |
After procedure A: |
50% |
Chromatographic test
Adsorbent: Silica gel F-254
Solution applied to the plate: Substance dissolved in water.
Solvent system:
chloroform ............................ 5 volumes
methanol ............................... 4 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: The plate is left in the air to dry, and then examined under ultraviolet light at a wavelength of maximum output at about 254 nm. The plate is then sprayed with 0.25% triketohydrindene hydrate in acetone and heated at 100 °C 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 sulfate display the same chromatographic characteristics of migration and detection, though after procedure A the spot is less intense and in addition, a secondary spot is revealed of much stronger intensity than the one obtained from the reference solution.
Ultraviolet spectrophotometry
The absorption spectrum is recorded using a 0.05% solution in water.
After procedure A, an absorption maximum at about 320 nm is observed that is not present in the reference solution.
Conclusion
Paromomycin sulfate is subject to decomposition under accelerated degradation conditions.
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