(1986; 119 pages)
Accelerated Degradation Experiment
30 days exposure at 50 °C and 100% relative humidity.
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 fine white or creamy white, crystalline powder, remains unchanged after procedure A, but acquires a heterogeneous white to yellowish colour after procedure B.
Gain of moisture
After procedures A and B:
Adsorbent: Silica gel F-254
Solution applied to the plate: Substance dissolved in methanol.
cyclohexane ................ 80 volumes
acetone ....................... 20 volumes
acetic acid .................. 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: The spots obtained from the solution of the sample subjected to procedure A and the spots obtained from the reference solution of phenylbutazone display the same chromatographic characteristics of migration and detection. No secondary spots are revealed. After procedure B, three additional spots are obtained that are less mobile than the main spot.
The degradation after procedure B was determined by acidimetry in acetone and assessed at 6.6%.
No decomposition is detected after procedure A, but phenylbutazone is subject to decomposition after procedure B.