In its 95+ year history, West has developed and marketed a very large number of elastomeric formulations, each designed to address particular market demands. Over this time, various aspects of drug product quality have gained attention – a fact reflected in the numerous regulatory guidances that have been issued. An early focus of these guidances was extractables and leachables, followed closely by particulate matter and container closure integrity. Beyond these regulatory requirements, the market demands product portfolios that enable platforming and predictable, consistent product quality and performance.