The principles of Quality by Design (QbD) have recently become a modern bellwether for pharmaceutical drug development that is being embraced by both the pharmaceutical industry and international regulatory authorities such as the FDA. The elements of QbD are fundamentally based on the concept that the quality of a new molecular entity should be designed into the product from the start and evolves as the product matures through its development lifecycle. This science and risk based philosophy to product development relies on the knowledge that grows as the compound progresses through nonclinical and clinical development. At the time of final market application filing and commercial launch, these well defined and thoroughly characterized pharmaceuticals are ideally positioned to meet the current and future needs of the patients that depend on these life saving medicines. Despite the relative novelty of the term �QbD� in modern pharmaceutical development, the principles of applying good science to understanding and controlling product quality have been a cornerstone of the pharmaceutical industry for many years. The focus of this presentation will highlight several key examples of how critical analytical knowledge and experience gathered during product development can be essential to ensuring successful regulatory submissions and maintaining overall product quality.