This guide supports the principles of Guide E2500 and extends these principles to the verification of PAT-enabled control systems.

This guide clarifies what is important for verification of PAT-enabled control systems. Such systems are often complex and require multidisciplinary and cross-functional teams to achieve optimum results. This guide provides a common basis for understanding requirements for all involved disciplines such as control engineering, development, manufacturing, and process validation.

1.1 This guide describes the verification of process analytical technology (PAT) enabled control systems using a science- and risk-based approach. It establishes principles for determining the scope and extent of verification activities necessary to ensure that the PAT-enabled control system is fit for purpose, properly implemented, and functions as expected.

1.2 In this guide, a PAT-enabled control system is considered to be the system that adjusts the manufacturing process using timely measurements (that is, during processing) of attributes of raw and in-process materials to determine responses that assure the process remains within specified boundaries and minimizes variability in the output material. The overall aim of the PAT-enabled control system is to ensure product quality. The PAT-enabled control system of a manufacturing process provides the capability to determine the current status of the process and drive the process to ensure the output material has the desired quality characteristics. The control system should be able to respond to process variations in a timely manner, providing corrections that ensure that the process follows the desired process trajectory to reach the desired outcome. PAT-enabled control systems may use process models based on first principles understanding or empirical models derived from experimental investigations or both. In addition to automated controls, a PAT-enabled control system may include components where there is manual intervention.

1.3 Principles described in this guide may be applied regardless of the complexity or scale of the PAT-enabled control system or whether applied to batch or continuous processing, or both.

1.4 The principles described in this guide are applicable to a PAT-enabled control system and also to its component subsystems. This guide does not cover the requirements for continuous quality verification of the overall process, which are covered in Guide E2537.

1.5 For information on science- and risk-based approaches in the pharmaceutical industry, reference should be made to ICH Q8(R2), ICH Q9, and ICH Q10. For guidance on PAT systems in the pharmaceutical industry, reference should be made to FDA Guidance for IndustryPAT and FDA Guidance for IndustryProcess Validation.

1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.