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 a white powder, turns black after a few days.
Gain of moisture
After procedure A: |
15% |
After procedure B: |
24% |
Chromatographic test
Adsorbent: Silica gel F-254
Solution applied to the plate: Substance dissolved in water.
Solvent system:
methanol: ..................................20 volumes
chloroform: ...............................80 volumes
concentrated ammonia: ............0.2 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 examined under ultraviolet light at a wavelength of maximum output at about 254 nm, and then left in a chromatographic chamber containing some iodine crystals until spots appear.
Results: After procedure A, the spot obtained from the solution of the sample is slightly less intense than the spot obtained from the reference solution of ergotamine maleate. In addition, a secondary spot appears.
After procedure B, the chromatogram remains unchanged.
Ultraviolet spectrophotometry
The absorbance is measured at about 311 nm using a 0.002% solution of the samples in ethanol 95%. After procedures A and B, a decrease of absorbance of about 25% is noted.
Colorimetric determination
The absorbance is measured at about 555 nm using a solution of the samples to which dimethylaminobenzaldehyde has been added.
After procedure A, a decrease of absorbance is noted corresponding to a decomposition of about 30%.
Conclusion
Ergotamine maleate is subject to decomposition under accelerated degradation conditions.
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