Accelerated Degradation Experiment
Conditions
Procedure A1: |
24 hours exposure at 50 °C and 100% relative humidity. |
Procedure A2: |
48 hours exposure at 50 °C and 100% relative humidity. |
Procedure A3: |
3 days exposure at 50 °C and 100% relative humidity. |
Procedure A4: |
30 days exposure at 50 °C and 100% relative humidity. |
Procedure B: |
30 days exposure at 50 °C and 100% relative humidity followed by 10 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 procedure A2 into a yellow powder, after procedure A3 into a viscous mass and finally after procedures A4 and B into a syrupy yellow-orange liquid which after cooling turns into a sticky, viscous paste.
Gain of moisture
Before exposure to heat and humidity: |
4.3% |
After procedures A4 and B: |
67% |
Chromatographic test
Adsorbent: Silica gel F-254
Solution applied to the plate: Substance dissolved in water.
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 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 secondary spots obtained from the solutions of each of the samples subjected to procedures A4 and B are more numerous than the corresponding spots obtained from the reference solution of dicloxacillin sodium.
Acidimetric titration
After procedure A3: |
20% degraded |
After procedures A4 and B: |
60% degraded |
Iodometric titration
After procedure A1: |
no degradation |
After procedure A2: |
7% degraded |
After procedure A3: |
29% degraded |
After procedures A4 and B: |
95% degraded |
Conclusion
Dicloxacillin sodium is subject to decomposition under accelerated degradation conditions.