Scaling Down Large-Scale Thawing of Monoclonal Antibody Solutions: 3D Temperature Profiles, Changes in Concentration, and Density Gradients

Abstract

Purpose Scale-down devices (SDD) are designed to simulate large-scale thawing of protein drug substance, but require only a fraction of the material. To evaluate the performance of a new SDD that aims to predict thawing in large-scale 2 L bottles, we characterised 3D temperature profiles and changes in concentration and density in comparison to 125 mL and 2 L bottles. Differences in diffusion between a monoclonal antibody (mAb) and histidine buffer after thawing were examined. Methods Temperature profiles at six distinct positions were recorded with type T thermocouples. Size-exclusion chromatography allowed quantification of mAb and histidine. Polysorbate 80 was quantified using a fluorescent dye assay. In addition, the solution’s density at different locations in bottles and the SDD was identified. Results The temperature profiles in the SDD and the large-scale 2 L bottle during thawing were similar. Significant concentration gradients were detected in the 2 L bottle leading to marked density gradients. The SDD slightly overestimated the dilution in the top region and the maximum concentrations at the bottom. Fast diffusion resulted in rapid equilibration of histidine. Conclusion The innovative SDD allows a realistic characterisation and helps to understand thawing processes of mAb solutions in large-scale 2 L bottles. Only a fraction of material is needed to gain insights into the thawing behaviour that is associated with several possible detrimental limitations.

Evaluation of Two Novel Scale-Down Devices for Testing Monoclonal Antibody Aggregation During Large-Scale Freezing

“…A detailed comparison of temperature profiles in the 2 L bottle, the SDD, and the 125 mL bottle during freezing as well as thawing was published previously. 30,31 The devices were gently homogenised by inverting the bottles five times and 1 mL triplicates collected. This process was repeated until five FT cycles were completed.…”

“…Thereby, the SDD significantly prolongs process time in comparison to an unshielded 125 mL bottle and mimics the cryoconcentration during freezing and the concentration gradients after thawing of a 2 L bottle. 30,31 With this approach the material need can be reduced 16-fold from 1.6 L to 100 mL. The same CFD based approach of matching stress time was realised in a micro SDD (mSDD) to scale the volume further down (Figure 1).…”