1. INTRODUCTION

Packaging systems, also referred to as container–closure systems, are defined in Packaging and Storage Requirements 〈659〉. These systems are the sum of components that together contain and protect the drug product and, in some cases, deliver the drug product to the patient. Drug products can chemically interact with their associated packaging system's metallic materials of construction. The magnitude of these interactions should not adversely affect the suitability of the packaged drug product, which includes both quality aspects and performance aspects such as efficacy, stability, purity, and compendial compliance. Suitability for use, as determined by the impact of the interaction between a drug product and its packaging system, is assessed and established via the appropriate testing of the materials of construction and the packaging/delivery systems. USP chapter Metallic Packaging Systems and Components 〈662〉 establishes the tests and acceptance criteria that are necessary and appropriate for ensuring that such systems are suitable for use.