Accelerated Degradation Experiment

Conditions

Appearance of the substance

The substance, originally in the form of a white, crystalline powder, changes after procedure A1 into a dark brown liquid.

Gain of moisture

Chromatographic test

Adsorbent: Silica gel F-254

Solution applied to the plate: Substance dissolved in methanol.

Solvent system:

n-butanol .............. 6 volumes
acetic acid ............ 2 volumes
water .................... 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 a chromatographic chamber containing some iodine crystals until spots appear.

Results: After procedure Al, the intensity of the main spots decreases slightly by comparison with the spots obtained from the reference solution of phentolamine mesilate. An additional less mobile spot is also observed.

Ultraviolet spectrophotometry

The absorbance of a solution of the sample subjected to procedure A1 indicates a degradation of 17.5%.

Conclusion

Phentolamine mesilate is subject to decomposition under accelerated degradation conditions.