4.1 Although some CM is used in the pharmaceutical industry (for example, purified water production), and some processes are inherently continuous individual unit operations (such as dry granulation and compression), these operations are generally operated in isolation and do not deliver the potential benefits of an integrated CM operation. The FDA Guidance for Industry PAT document specifically identifies that the introduction of continuous processing (now redefined as CM) may be one of the outcomes from the adoption of a science-based approach to process design.

4.2 This guide does not:

4.2.1 Suggest that CM is suitable for the manufacture of all pharmaceutical products.

4.2.2 Provide guidance on issues related to the safe operation of a CM process or continuous processing equipment. It is the responsibility of the user of this standard to establish appropriate health and safety practices and determine the applicability of regulatory limitations prior to use.

4.2.3 Recommend particular designs or operating regimes for CM.

4.3 Appendix X1 includes a table comparing the characteristics of continuous and discrete or batch processes.

1.1 This guide introduces key concepts and principles to assist in the appropriate selection, development and operation of CM technologies for the manufacture of pharmaceutical products. Athough selected concepts covered here can be applied to biopharmaceutical CM (BioCM), the focus of this guide is on non-biopharmaceutical applications.

1.2 Particular consideration is given to the development and application of the appropriate scientific understanding and engineering principles that differentiate CM from traditional batch manufacturing.

1.3 Most of the underlying concepts and principles (for example, process dynamics and process control) outlined in this guide can be applied to both Drug Substance (DS) and Drug Product (DP) processes. However, it should be recognized that in Drug Substance production the emphasis may be more on chemical behavior and dynamics in a fluid phase whereas for solid drug product manufacture there may be a greater emphasis on the physical behavior and dynamics in a solid/powder format.

1.4 This guide is also intended to apply in both the development of new processes, or the redesign of existing ones.

1.5 All values are stated in SI units. No other units of measurement are included in this standard.

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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.