(542f) A Comprehensive Investigation of Process Design and Parameters of Spray Dried Proteins

Biopharmaceuticals, such as monoclonal antibodies, represent an important field in the pharmaceutical industry. Development and production of these valuable and complex substances is costly and the resulting price on the market for a single dose can reach more than thousand euros. This highlights the demand of processing these biopharmaceuticals in a sensitive way to preserve their activity and stability. The majority of biopharmaceutics is formulated as liquid solutions. Proteins are more susceptible to physico-chemical degradation in liquid state, thus various stabilizers are needed to prevent self-aggregation and denaturation. The conversion of these biologics from the liquid to the solid state by removing their natural environment does not appear to be intentional at first glance. However, removing water decreases the proteins mobility and stabilizes the protein. Additionally, dried protein powders convince in eased handling, storage and transportation.

Freeze drying is currently the gold standard, when protein formulations are transferred into dry solid powders. Briefly, freeze drying of a protein formulation is based on converting the liquid protein formulation to a solid state by freezing and eventually removing the water by applying vacuum (i.e. sublimation). However, freeze drying is time intensive during processing and handling. A promising alternative is spray drying of proteins. The protein formulation is atomized by a spray nozzle. The finely dispersed droplets are dried by a heated gas flow (e.g. air, nitrogen) and subsequently collected. Spray drying allows for a vast decrease in processing time, processing at atmospheric pressure and mild drying temperatures, the control of powder particle properties, and remaining water content.

We developed a stable drying process for different model proteins by optimizing the yield and residual moisture. The structural stability, activity and properties in solid state of the protein were assessed by a standardized set of methods. The talk will highlight the lessons learned and provide further steps towards understanding the impact of spray drying. An outline to support industrialization of the process design and development for spray drying as alternative technology will be presented to fully exploit its benefits.