Aspects of the Design of Preparative Chromatography for Purification of Antibodies

Sammanfattning: The development of biotechnological products is becoming more and more expensive. One type of protein attracting a great deal of attention in the biopharmaceutical industry is antibodies, which was used in this work. The cost of producing antibodies is, however, high, mainly due to the downstream processing, which constitutes 50–80% of the total cost. This work describes model-based methods to design a chromatography purification step and the important underlying physical phenomena. The model used was a general rate model or a reaction dispersive model with two different adsorption descriptions, Langmuir Mobile Phase Modulators and Steric Mass Action. The diffusion of protein in gels was studied using holographic methods as Electronic Speckle Pattern Interferometry and Holographic Interferometry and also by chromatography breakthrough experiments. The adsorption kinetic data was obtained using chromatography elution experiments with different gradients. Different methods to calibrate an ion-exchange model were studied. The model was then used to optimise the operating conditions and to perform a model-based robustness analysis. The methods suggested in this thesis are a step towards reducing time for development, capital expenditure and labour costs in the downstream process.