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14 BioPharm International ® Partnerships for Outsourcing eBook May 2023 www.biopharminternational.com Process De veloPment Understanding the product Diligent process characterization is an important part of process design; and through it, patient safety is en- sured throughout the therapeutic's manufacturing process. The starting point for process characteri- zation is understanding the product: what is the ex- pected product profile? The target profile sets the qual- ities that are sought within each step of the process. As an example, when a new monoclonal antibody (mAb) enters drug substance process development, the desired product quality attributes are set, and its physical properties are known, even if further safety and efficacy targets are later refined from preclin- ical and clinical work. Those quality attributes set the manufacturing process; the process is designed to consider and/or control the product quality, and the acceptable operating ranges must ensure drug safety and efficacy. To identif y the product's def ining critical pro- cess parameters (CPPs), all parameters are initially assessed for their impact on the final product pro- file. That assessment sets the process targets, which are developed and then optimized during process development and characterization. Upon comple- tion of process characterization, the design space is finalized, and in turn, the control strategy elements are set. The accumulated variables (process parameters) and operating ranges connected to product quality at- tributes are outlined in the control strategy. More spe- cifically, the control strategy details the material input; the process, including procedural and process parame- ter controls; and the testing requirements, which cover in-process testing and product specifications. The accumulated knowledge and understanding in commercialization enhance the approach for com- mercialization of each subsequent product. Experi- ence cultivates continuous improvement and enables the streamlined qualification of new products. Previ- ous knowledge with similar types of molecules assists in the design of a targeted platform process. One such method is to follow a f lowchart, as shown in Figure 1, which covers process optimization, and leverages risk assessments based on failure mode and effect analysis (FMEA) methodology. Following this process helps to identif y critical quality attributes (CQAs) for the mAb, presumptive CPPs, and presumptive critical material attributes. Diligent process characterization is an important part of process design. FIGURE 1. Flexible process characterization (PC) pathway to fit different monoclonal antibody (mAb) scenarios. FMEA is failure mode and effect analysis; CQAs are critical quality attributes; CPPs are critical process parameters; and DoE is design of experiment. FIGURES COURTESY OF THE AUTHORS