The influence of thermal and shear stressors on the stability of the anti-TNF-α monoclonal
antibody (mAb), Infliximab® (INF) was investigated. INF at concentrations of 1, 4 and 10 mg/ml was
subjected to thermal stress at temperatures of 25-65°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°C.
At 65°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 1mg/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