Peroxide Residual and Oxidation of mAb2 Formulation (25 mg/mL) Spiked with Various Concentrations of H2O2 at 5 °C Storage
| Assay | Time (months) | H2O2 Concentration (ng/mL) | |||||
|---|---|---|---|---|---|---|---|
| 0 (control) | 10 | 50 | 250 | 1000 | 5000 | ||
| Amplex® UltraRed HRP Assay—Peroxide (ng/mL) | 0 | <LOD | 13 | 50 | 239 | 1075 | 5821 |
| 3 | <LOD | <LOD | <LOD | 23 | 138 | 901 | |
| 6 | <LOD | <LOD | <LOD | <LOD | 15 | 182 | |
| 9 | <LOD | <LOD | <LOD | <LOD | <LOD | 35 | |
| 12 | <LOD | <LOD | <LOD | <LOD | <LOD | 6 | |
| 18 | <LOD | <LOD | <LOD | <LOD | <LOD | <LOD | |
| 24 | <LOD | <LOD | <LOD | <LOD | <LOD | <LOD | |
| Peptide Mapping—HPLC | |||||||
| % Met 252 Oxidation | 0 | 2.5 | NT | NT | NT | NT | NT |
| 3 | 2.5 | 2.5 | 2.6 | 3.5 | 7.0 | 23.7 | |
| 6 | 2.4 | 2.4 | 2.3 | 3.4 | 7.1 | 26.1 | |
| 9 | 2.9 | 2.8 | 2.9 | NT | NT | 28.3 | |
| 12 | 2.3 | 2.6 | 2.7 | NT | NT | NT | |
| 18 | 3.7 | 3.5 | 3.8 | NT | NT | NT | |
| 24 | 4.9 | 4.5 | 4.8 | NT | NT | NT | |
| % Met 428 Oxidation | 0 | 1.6 | NT | NT | NT | NT | NT |
| 3 | 1.3 | 1.3 | 1.5 | 2.0 | 4.3 | 14.6 | |
| 6 | 1.2 | 1.1 | 1.2 | 1.7 | 3.6 | 13.7 | |
| 9 | 1.2 | 1.1 | 1.2 | NT | NT | 12.3 | |
| 12 | 1.0 | 1.1 | 1.0 | NT | NT | NT | |
| 18 | 1.7 | 1.5 | 1.8 | NT | NT | NT | |
| 24 | 2.8 | 2.8 | 2.9 | NT | NT | NT | |
HPLC, high-performance liquid chromatography; HRP, horseradish peroxidase; LOD, limit of detection; NT, not tested.