Container closure compatibility of therapeutic products is a regulatory requirement to protect potency, efficacy and safety of active ingredients.In pre-filled syringes a range of materials gets in immediate contact with sensitive biomols.: silicone oil, tungsten, elastomer closure, plunger, glass and - for staked needle syringes - adhesive as well as needle.This presentation provides an overview of strategies and processes developed for pre-filled syringes to mitigate stability risks for sensitive biopharmaceutical formulations.The focus is placed on alkalinity, silicone oil and tungsten as sources of incompatibilities.Surface treatment methods to stabilize pH, baked-on siliconization technologies to reduce silicone oil levels and tungsten-free production techniques to avoid tungsten leachables are outlined.How partnerships between biopharmaceutical companies and manufacturers of pre-filled syringes achieve best results for product stability is demonstrated.