Table 4.
Results of forced degradation studies of CPS injection formulation
| Stress conditions | CPS % | Total impurities (%) | Mass balance (%) | Remarks |
|---|---|---|---|---|
| Control | 101.15 | 0.09 | 101.24 | — |
| Base hydrolysis (1 N NaoH, 6 hours) | 97.48 | 3.31 | 100.79 | Imp-3 was major degradation product. |
| Acid hydrolysis (0.01 N H3PO4, 40 mins) | 100.09 | 1.26 | 101.35 | Imp-1, 2, 3 increased. |
| Thermal treatment (60 ℃, 10 days) | 95.58 | 6.55 | 102.13 | Imp-1, 2, 3 increased. |
| Oxidation condition (0.025 g mL-1 KMnO4, 40 mins) |
100.38 | 0.13 | 100.51 | Two unknown degradation products formed designated as U1, U2. Imp2 and imp-3 were undetected. |
| Photolytic condition (4500 Lx ± 500, 10 days) | 100.81 | 0.10 | 100.91 | Mild degradation was observed. |