Container-content compatibility studies are required as part of the submission of a new product market authorization file or for a change relating to the primary product-contact packaging. Many regulatory publications and guidances are available in the USA, Europe, and Japan. However these publications and guidances are not sufficiently precise enough to allow for consistent interpretation and implementation of the technical requirements. A working group has been formed by the French Society of Pharmaceutical Science and Technology (SFSTP) in order to propose guidance for container-content interaction studies that meet both European and US requirements, and allows consistent and standardized information to be presented by the industry to the regulators. When a pharmaceutical drug product remains in prolonged contact with a material, the two critical points to consider are the drug product's quality and safety. A pharmaceutical evaluation of the container-content relationship should be done based on the knowledge of the contact material (e.g., type, physicochemical properties), its manufacturing processes (e.g., the type of sterilization that could potentially alter the interactions), and the formulation components involved in contact with this material (e.g., physicochemical properties, pharmaceutical presentation, route of administration). Quality is evaluated using the stability study performed on the product. Safety is partially evaluated with the stability study and is analyzed in conjunction with toxicity testing, specifically with cytotoxicity testing. The toxicity aspect is the key point of the container-content compatibility study and of patient safety. Migration tests are conducted when an interaction is suspected, or found based on previous results, to identify the component responsible for this interaction and to help select a new material if needed. Therefore, such tests are perhaps not the best ones to use for the purpose of safety evaluation. Consequently, a decision tree based mainly on the toxicity aspect is proposed in order to support the pharmaceutical companies' container-content interaction approach and filing.