The successful formulation of protein biopharmaceuticals requires proactive strategies to mitigate direct threats such as protein misfolding and degradation and to ensure product quality, stability, and functionality. Excipients play a crucial role in stabilizing recombinant proteins, especially as these are increasingly formulated in higher concentrations. Proper excipient selection enhances product shelf-life and effectiveness, but optimizing the pharmaceutical presentation is also vital for therapeutic efficacy and patient compliance. This includes careful consideration of product format, packaging, administration devices, and routes. Regulatory agencies ensure the quality, safety, and efficacy of these products through detailed guidelines. Innovative approaches include advancements in formulation, such as new excipients and formats, as well as cutting-edge in silico tools for enhancing protein stability and predicting formulation behavior, promising significant progress in the field. This chapter provides an in-depth overview of the formulation and development strategies essential for maintaining protein quality, safety, and efficacy in protein biopharmaceuticals. It also discusses current and future advancements in excipients, which may help overcome current viscosity limitations in highly concentrated antibody-based products and highlights the need for excipient-specific evaluation programs by competent authorities.