The aim of this work is to understand the molecular mobility behaviour and structural dynamics of seven distinct protein excipient mixtures, and the dependance of each on temperature. We investigate the effect of different excipients, including sucrose, trehalose, L-arginine, and polysorbate 80 on each distinct formulation, with bovine serum albumin (BSA) as a model protein. We furthermore investigate the effects of adding polysorbate as well as altering the concentration on three monoclonal antibody (mAb) containing formulations. By comparing systems which contain the higher molecular weight and Y-shaped mAb versus globular BSA, we can investigate the effects of molecular weight and structure in the lyophilised formula-tions. We aim to provide a comprehensive understanding of the molecular dynamics of the material leading up to the glass transition temperature (T g ), and a relationship between the relaxation dynamics and the molecular structure of the lyophilised formulations.