Bulk Protein Solution: Freeze–Thaw Process, Storage and Shipping Considerations

Protein drug substance is typically frozen to enable manufacturing flexibility through prolonging the shelf life of drug substance and providing better biochemical stability. The process of freezing and thawing of bulk protein solutions poses several challenges. It is important to understand the process and define mitigation strategies to address these challenges. Just not the process but the choice of storage container can have an impact on stability and downstream operation of formulation during drug product process. Therefore, understanding the options currently available in terms of drug substance storage containers and how to balance the need based on specific scenarios is critical. Storage temperature is as important as the container the drug substance is stored at. Furthermore, shipping drug substance in frozen state requires thorough understanding of logistics and dependence of shipping temperature on stability. This chapter fundamentally looks at the freezing and thawing process, discusses phenomenon of cryoconcentration in various containers and mitigation strategies, consequence of not choosing appropriate storage temperature, and provides considerations for storage and shipping of drug substance.