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 2 days at 70 °C and 100% relative humidity. |
Appearance of the substance
The substance, originally in the form of a white or almost white, crystalline powder, changes after procedures A and B into agglomerates.
Gain of moisture
After procedures A and B: |
20% |
Chromatographic test
Adsorbent: Silica gel F-254
Solution applied the plate: Substance dissolved in methanol.
Solvent system
ethylmethylketone........... 6 volumes
pyridine.......................... 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 sprayed with a 0,1% solution of triketohydrindene hydrate.
Results: The reference solution of penicillamine displays a main spot at Rf ~0.8 and two minor spots at Rf ~0.2. The less mobile spots obtained for each of the samples subjected to procedures A and B increase in intensity, whereas the main spot decreases.
Colorimetric determination
The content of penicillamine is determined with blue tetrazolium and tetrabutylammonium hydroxide and the absorbance is measured at 530 nm.
After procedure A: |
70% |
After procedure B: |
60% |
Conclusion
Penicillamine is subject to decomposition under accelerated degradation conditions.
Loading...
