Accelerated Degradation Experiment

Conditions

Appearance of the substance

The substance, originally in the form of colourless crystals or a greyish white to yellowish white, crystalline powder, changes after procedure A into a greyish powder and after procedure B into a black powder.

Gain of moisture

Chromatographic test

Adsorbent: Silica gel F-254

Solution applied to the plate: Substance dissolved in water containing 1% of tartaric acid.

Solvent system:

methanol: ......................................100 volumes
concentrated ammonia: ..................1.5 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: The spots obtained from the solution of the sample subjected to procedure A and the spots obtained from the reference solution of ergotamine tartrate display the same chromatographic characteristics of migration and detection. No secondary spots are revealed. After procedure B, the R_f value of the main spot is modified with a decrease in intensity.

Ultraviolet spectrophotometry

The absorbance is measured at about 239 nm using an aqueous solution containing 1% of tartaric acid.

Colorimetric determination

The absorbance is measured at about 400 nm using a solution to which picric acid has been added.

Conclusion

Ergotamine tartrate is subject to decomposition under accelerated degradation conditions.