PAT is a manufacturing methodology for high value chemicals and pharmaceuticals in which critical parameters (CPP) and key performance indicators (KPI) of the process are thoroughly understood, well-defined and continually monitored in order to ensure that the pre-defined critical quality attributes (CQA) of the final product are consistently achieved. PAT measures key quality and performance indicators in raw materials, in-process materials and processes in real-time. A well designed PAT-based process is stable, ensuring that the critical parameters and indicators remain within pre-described limits to ensure product quality and process safety. PAT is an important element in a Quality by Design (QbD) system, in which quality is not tested into product, but rather inherent, by-design. PAT is an orthogonalized application of chemical, physical, microbiological, mathematical, and risk analysis elements resulting in a complete understanding and control of processes. PAT is applicable to many of the standard operations performed in chemical processes such as reaction monitoring and crystallization procedures.
Process Analytical Technology (PAT) utilizes a variety of tools, such as spectroscopic and chromatographic compositional analyzers, fixed purpose sensors, automated and statistical data analysis and overall knowledge management methods. All of these technologies and methods are designed to provide information in a real-time or near real-time manner. Since the purpose of PAT is to improve the safety and quality of manufactured products, it must be incorporated into efforts leading to large-scale production such as early and late stage process development and process scale-up. The application of PAT methodology represents a technological and cultural shift in how a company or an industry approaches development, manufacturing, quality and safety.