Stress Degradation Behavior of Paliperidone, an Antipsychotic Drug, and Development of Suitable Stability-Indicating RP-LC Method
Table 3
Forced degradation results.
Stress condition
% assay of paliperidone
% of degradant
Observation and Mass balance
Peak purity
PA
PT
Undegraded
99.70
—
0.080
0.258
Acid hydrolysis (conc. HCl, 4 h refluxed)
74.83
25.13
Increase in levels of Imp-A (1.25%) and Imp-C (13.01%) and other 10.88 % of unknown degradation product formed (mass balance: 99.96%)
0.226
0.251
Base hydrolysis (5 M NaOH, 48 h refluxed)
88.59
11.05
Increase in levels of Imp-A (0.31%), Imp-B (1.69%) and other 7.82 % of unknown degradation product formed (mass balance: 99.00%)
0.195
0.248
Oxidation (6% H2O2 at RT)
72.11
27.77
Increase in levels of Imp-A (0.14%) and major degradation product, that is, Imp-D (24.51%) and other 3.12 % of unknown degradation product formed (mass balance: 99.64%)
0.079
0.250
Thermal (60°C, 8-days)
99.85
Nil
No any known and unknown degradation product formed (mass balance: 100.3%)
0.078
0.258
Photolytic as per ICH
99.63
Nil
No any known and unknown degradation product formed (mass balance: 99.2%)
0.080
0.258
Mass balance = % assay + % sum of all impurities + % sum of all degradants. PA, purity angle; PT, purity threshold.
