Effect of Thermal and Shear Stressors on the Physical Properties, Structural Integrity and Biological Activity of the Anti-TNF-alpha Monoclonal Antibody, Infliximab

The influence of thermal and shear stressors on the stability of the anti-TNF-alpha monoclonal antibody (mAb), Infliximab (R) (INF) was investigated. INF at concentrations of 1, 4 and 10 mg/ml was subjected to thermal stress at temperatures of 25-65 degrees C and to shear force by sonication for 1 and 3 minutes. The stressed samples were analysed for physical properties by particle size, zeta potential, for structural integrity by gel electrophoresis (SDS-PAGE) and circular dichroism, INF content by UV spectroscopy and for biological activity by ELISA. Results show no change in physical properties or structural integrity of INF at any concentration tested, when subjected to a temperature of up to 50 degrees C. At 65 degrees C, aggregation and precipitation of INF was observed. When subjected to shear stress, higher concentrations of INF at 4 and 10mg/ml maintained their physical properties and structural integrity. However, the biological activity of INF was found to decrease with increasing temperature and sonication time, and was concentration dependent (ANOVA; p<0.05). Interestingly, lyophilisation of INF at 1 mg/ml did not affect its physical properties, structural integrity or its biological activity. These findings have important implications with respect to pharmaceutical processing of INF and mAbs including formulation as polymeric micro and nanoparticle systems for sustained or targeted delivery. These findings also have important implications with respect to the handling and storage of INF and mAbs for clinical use.