Optimization and Validation of a Liquid Formulation for a New Recombinant Veterinary Product using QbD Approach

Protein formulation and drug characterization are one of the most difficult and time-consuming tasks because of the complexity of biotherapeutic proteins. Hence, maintaining a protein drug in its active state typically requires preventing changes in its physical and chemical properties. Quality by Design (QbD) is a systematic approach emphasizing product and process understanding. Design of Experiments (DoE) is one of the most important QbD tools, allowing the possibility to modify the formulation attributes within a defined design space. Here, we report the validation of a RP-HPLC assay for recombinant equine chorionic gonadotropin (reCG) that demonstrated a high correlation with the in vivo potency biological assay. QbD concepts were then applied to obtain an optimized liquid formulation of reCG with a predefined quality product profile. The developed strategy demonstrates the importance of applying multivariable strategies as DoE to simplify formulation stages, improving the quality of the obtained results. Moreover, it is important to highlight that this is the first time that a liquid formulation is reported for an eCG molecule, since, up to now, the only eCG products available in the market for veterinary use consisted in partially purified preparations of pregnant mare serum gonadotropin (PMSG) presented as a lyophilized product.