How to Identify Critical Process Parameters 

How to Identify Critical Process Parameters 

Identifying critical process parameters (CPPs) is essential for ensuring the quality, safety and efficacy of pharmaceutical products. Critical process parameters are the key input variables that can affect the quality and consistency of a product. Failure to appropriately control these parameters can result in production failures, batch rejections and product recalls. 

Identifying critical process parameters involves correlating manufacturing process data with finished product testing results. This shows which variables have the greatest impact on product quality. Once these parameters have been identified, they must often be controlled to ensure they remain within established limits. Regulatory agencies like the U.S. Food and Drug Administration (FDA) require pharmaceutical manufacturers to identify critical process parameters as part of process development prior to filing for marketing authorization. This ensures the manufacturing process is robust and that appropriate control strategies are in place to minimize process variability and guarantee that final products meet the mandatory quality standards. 

Identifying Critical Quality Attributes (CQA) and Critical Process Parameters (CPP) 

Identification of CQA and CPP is essential to identify the quality attributes most critical to your product's performance. Quality attributes are the physical, chemical, biological or microbiological characteristics necessary to ensure the product's efficacy and safety. These attributes may include, but are not limited to, purity, potency, dissolution rate, particle size, and sterility. Once the critical quality attributes have been identified, the next step is to determine which process parameters may have the greatest impact on critical quality attributes. 

Understanding Process Variables 

Understanding the process variables that can impact quality attributes is crucial. These variables may occur anywhere through production and processing and can include equipment, environmental conditions, raw materials, manufacturing procedures, and personnel. Understanding the impact of each variable on the product's quality attributes is necessary to determine which variables count as critical process parameters. 

Linking Process Parameters & Quality Attributes 

Statistical methods determine the relationship between process parameters and quality attributes. Design of Experiments (DoE) is a statistical methodology widely used in the pharmaceutical industry to identify critical process parameters. DoE allows for the evaluation of multiple process parameters simultaneously and can help to identify interactions between process parameters that may impact quality attributes. Additionally, statistical process control (SPC) methods can be used to monitor process parameters and ensure that they remain within specified limits. 

Validating Critical Process Parameters 

Once critical process parameters have been identified, the next step is to establish control limits. Control limits are the acceptable ranges for each process parameter and are established based on the product's critical quality attributes. These limits may be determined based on historical data, industry standards or regulatory requirements. 

It is crucial to validate critical process parameters to ensure that they are operating within established control limits. Validation is the process of demonstrating that a process consistently produces a product that meets the desired quality attributes. Process validation involves three stages: process design, qualification and continued process verification.  

  • Process Design Stage: Critical process parameters are identified and control limits are established.  
  • Qualification Stage: Determination of whether the process can consistently produce within the established control limits is qualified.  
  • Continued Verification: The process is monitored on an ongoing basis to ensure it remains within the established control limits. 

Defining critical process parameters is a critical step in pharmaceutical manufacturing. It is essential to identify the critical quality attributes of the product, understand the impact of process variables on these attributes and use statistical methods to determine critical process parameters.  

Once critical process parameters have been identified control limits must be established, and the process must be validated to ensure that it consistently produces a product that meets the desired quality attributes. By following these steps, healthcare product developers can ensure that their products are of high quality, safe, and effective. 

Need Assistance Defining Critical Process Parameters? 

DS InPharmatics offers regulatory, technical, and project management consulting services to healthcare product companies. We have helped our clients enhance their product development, approval and marketing presence with innovative strategies and exceptional quality work products since 2007. With experience in all major therapeutic areas and all classes of pharmaceutical products, including over 30 product approvals, we are confident in our ability to help your company with its critical process parameter needs.

Contact us today to take the first step in ensuring your product's quality, safety, and efficacy. 


  1. U.S. Food and Drug Administration. “Guidance for Industry: Process Validation: General Principles and Practices.” 
  1. International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH). “Q8(R2) Pharmaceutical Development.”