Is FDA's Draft Process-Validation Guidance a Mixed Blessing?

The US Food and Drug Administration’s Draft Guidance for Industry-Process Validation: General Principles and Practices provides a life-cycle approach for validating pharmaceutical processes and aims to help pharmaceutical companies achieve consistently high product quality. The document includes several concepts that are familiar to the industry but also contains ambiguities and recommendations that might be difficult for some drugmakers to follow.

The draft guidance suggests manufacturers establish links from their clinical process to their commercial-manufacturing process. This approach is similar to the one FDA has used in its preapproval inspections. If the guidance becomes final as it currently stands, manufacturers may be expected to use the data that they gain during formulation and development to define a product’s critical attributes, which would be the basis for the manufacturing-process parameters.

The agency points out that development and formulation data can improve a company’s understanding of its processes during scale-up and commercial manufacturing. This understanding would help companies control variability and increase product quality, says Chris Ames, director of global validation at Catalent Pharma Solutions (Somerset, NJ). Companies would submit these data to FDA to establish links between clinical and commercial processes.

But the draft guidance does not advise manufacturers about how to identify the most important characteristics of its product or manufacturing process, or about how to demonstrate links from the clinical to commercial process. “They’ve left it completely open to interpretation as to what data you provide and what format you use,” says Jim Agalloco, president of Agalloco and Associates. This ambiguity would suit Big Pharma because it frees companies to use their experience and discretion in deciding how to follow the guidance, says Agalloco. Small and emerging drugmakers, however, would likely be confused because they don’t have the depth of knowledge that would help them define critical attributes.

Some elements of the draft guidance resemble a Six Sigma approach to manufacturing, which is familiar to the pharmaceutical industry. The main similarity is the draft guidance’s recommendation of a statistical link that demonstrates that variability remains constant from the clinical through the commercial manufacturing stages. The statistical link is intended to confirm that processes are the same throughout all phases.

Although the draft guidance suggests statistical analysis, it leaves industry with only a broad understanding of what that means. FDA does not explicitly suggest that manufacturers use particular statistical tools, the agency simply recommends that companies apply good statistics to establish the links, says Agalloco.

The draft guidance suggests manufacturers define a process that can be measured, analyzed, improved, and controlled, and this approach is closely related to Six Sigma. The benefit of the Six Sigma technique is that it provides a mechanism for scientific review of a process, for assessing variability, and for identifying improvements, says Ames.

On the other hand, it is unclear whether the draft guidance recommends a product be refined in the way that a Six Sigma approach would. “To me, Six Sigma implies an acceptance by FDA that you might not have done a sufficient job in development and scale-up and are allowed to improve product and process while it is in operation,” says Agalloco. Patients’ experiences with a product might persuade a manufacturer that it should adjust one of the drug’s parameters to improve it. Six Sigma would allow postcommercialization changes to a product, but the draft guidance may not be compatible with them, Agalloco says.

Before it could submit a regulatory filing, a company would have to spend a great deal of time and money to better understand its ingredients, its product, its manufacturing process, its material handling, and associated variables. Pharmaceutical companies might object to the draft guidance’s approach because it suggests this expensive work be completed before commercialization, but the costs would not be recoverable before commercial-scale manufacturing began.

Although it is based on good science, if the final guidance is approved as drafted, it could easily increase drug-development time by one or two years, thus costing a manufacturer millions of dollars, says Warren Charlton, a consultant at WHC Bio Pharma Technical Services. Manufacturers would need to use smart strategies to shorten development time, but not knowing how much data regulators expect in a submission would make this strategy difficult.

The draft guidance inspired a huge volume of comments that will likely take FDA a long time to review, says Agalloco. Even though the guidance might not be final for at least a year, manufacturers would be wise to study it now and seek advice about interpreting it. In this difficult time for the pharmaceutical industry, no company can afford to ignore regulators’ recommendations, and advance preparation would be to a manufacturer’s benefit.