1. Introduction 2. Polysorbate Surfactants used in biopharmaceuticals: An overview including in vivo fate and toxicology perspective 3. Surfactants (polysorbate and poloxamer) synthesis and degradation: Overview and relevance 4. Mechanisms of stabilization of proteins by surfactants 5. Behaviour of surfactant during processing (UF/DF, filter adsorption) 6. Analytical methods for surfactant characterization in Drug Product 7. Oxidative degradation of surfactants: Mechanisms 8. Hydrolytic degradation of surfactants and impact on protein stabilization 9. Regulatory Perspective on Surfactant Monitoring and Control 10. Control strategies to address surfactant degradation: A quality perspective 11. A look to the future - closing remarks