Computational fluid dynamic simulations of temperature, cryoconcentration, and stress time during large-scale freezing and thawing of monoclonal antibody solutions.

Purpose: Large-scale freezing and thawing experiments of monoclonal antibody (mAb) solutions are time and material consuming. Computational Fluid Dynamic (CFD) modeling of temperature, solute composition as well as the stress time, defined as the time between start of freezing and reaching T' at any point in the container, could be a promising approach to ease and speed up process development.

Methods: Temperature profiles at six positions were recorded during freezing and thawing of a 2L rectangular bottle and compared to CFD simulations via OpenFOAM.

The effect of mAb and excipient cryoconcentration on long-term frozen storage stability - part 2: Aggregate formation and oxidation.

We examined the impact of monoclonal antibody (mAb) and buffer concentration, mimicking the cryoconcentration found upon freezing in a 2 L bottle, on mAb stability during frozen storage. Upon cryoconcentration, larger protein molecules and small excipient molecules freeze-concentrate differently, resulting in different protein to stabiliser ratios within a container. Understanding the impact of these shifted ratios on protein stability is essential.

The effect of mAb and excipient cryoconcentration on long-term frozen storage stability - Part 1: Higher molecular weight species and subvisible particle formation.

Cryoconcentration upon large-scale freezing of monoclonal antibody (mAb) solutions leads to regions of different ratios of low molecular weight excipients, like buffer species or sugars, to protein. This study focused on the impact of the buffer species to mAb ratio on aggregate formation after frozen storage at -80 °C, -20 °C, and - 10 °C after 6 weeks, 6 months, and 12 months. An optimised sample preparation was established to measure T' of samples with different mAb to histidine ratios via differential scanning calorimetry (DSC).

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

There is a need for representative small volume devices that reflect monoclonal antibody (mAb) aggregation during freezing and thawing (FT) in large containers. We characterised two novel devices that aim to mimic the stress in rectangular 2 L bottles. The first scale-down device (SDD) consists of a 125 mL bottle surrounded by a 3D printed cover that manipulates heat exchange.

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

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.

Cryoconcentration and 3D Temperature Profiles During Freezing of mAb Solutions in Large-Scale PET Bottles and a Novel Scale-Down Device.

Purpose: Small-scale models that simulate large-scale freezing of bulk drug substance of biopharmaceuticals are highly needed to define freezing and formulation parameters based on process understanding. We evaluated a novel scale-down device (SDD), which is based on a specially designed insulation cover, with respect to changes in concentration after freezing, referred to as cryoconcentration, and 3D temperature profiles. Furthermore, the effect of the initial monoclonal antibody (mAb) concentration on cryoconcentration was addressed.