Buffer Selection in Biologics Manufacturing

Taking sample from biotechnological bioreactor in microbiological laboratory.

They’re far less exciting than the life-changing treatments they help create, but buffers play a critical role in upstream and downstream biomanufacturing processes. ANGUS takes you backstage with “Buffers in Biologics Manufacturing” – an in-depth article co-authored by Dr. Dave Green, Vice President of R&D, ANGUS, that explores the important variables to consider when selecting the right buffer (and buffer supplier). And, when it comes to biomanufacturing, we know a thing or two about buffers. Why? Because we invented them.

As the world’s only fully integrated manufacturer of globally compliant Tromethamine buffers, ANGUS Life Sciences is dedicated to what matters most – providing a secure, sustainable supply of high-quality buffers and biochemicals that are safely manufactured and delivered through reliable, traceable supply chains. The company is committed to producing the highest purity TRIS AMINO® buffers to meet the dynamic needs – as well as the regulatory and performance requirements – of the global customers the company serves.

The evolution of biotechnology has enabled the commercialization of protein-based drugs, including insulin, growth factors, blood factors and antibodies. The production and purification of these biologic products require the use of different buffers for pH control and stabilization of the reactions in the various steps during manufacture.

Biologic processes include the cell culture production or “upstream” phase, the purification or “downstream” phase, and the phase in which excipients for the drug product are introduced, or “formulation and storage” phase. In upstream processes, buffers are primarily used for their capacity to help maintain the pH within a specific range, optimizing conditions for cell growth and expansion, promoting production of the desired protein product and maintaining the protein product’s functional characteristics during primary recovery prior to the purification stages.

In downstream processes, buffers maintain defined purification conditions, control the ionization state of the product as necessary for column chromatography, and stabilize the product while maintaining the product’s functional characteristics.

For formulation and storage, buffers ensure optimal biological activity and stability of the product at the storage temperature and for the duration required for clinical or commercial use.

In selecting the correct buffer, it is important to consider the function and composition of the buffering solution for a specific stage of your process. A single step of the purification process can include several buffer compositions, depending on the complexity of operation. Additional buffers are used in equipment equilibration and cleaning. When buffers are included to maintain a stable pH, and once a suitable pH for protein stability and solubility has been determined, other components such as salt, reducing agents and/or stabilizers (e.g., polyols or detergents) that prevent protein aggregation are added once a suitable pH for protein stability and solubility has been determined.

To prepare solutions needed for process operations, buffer components and other dry additives are commonly added to water in powder form. Chemical compatibility must be demonstrated for such components with each other, as well as the environmental conditions to which they will be exposed (e.g., temperature changes, light exposure). Additional factors to be considered are temperature shifts that can affect pH and buffering capacity of some chemicals; compatibility with salts, detergents or reducing agents used in particular operations; special storage conditions; and compatibility with analytical assays.