In this review, we will provide a brief description of protein stability considerations in formulation development and an overview of emerging drying techniques and their applications in Section 2; protein dynamic and stabilization mechanism of biologics in solid state in Section 3, mechanistic factors that impact protein stability in Section 4, mechanism driven drug product design from optimizing formulation composition in Section 5, and new and evolving modalities and delivery of non-parenteral biologics will be discussed in Section 6. Overall, our focus is to elaborate structural mechanisms that underlie protein stability and provide a mechanistic understanding of the protein-excipient stabilization at the molecular level and provide rationale selection of excipients for solid biological formulation. These insights would be critical to address the stability-related issues in dried protein formulation.