FDA Details Manufacturing Expectations in Stent Guidance

Manufacturers of drug-eluting stents may not have to perform certain finished-product tests if they can link in-process controls to critical quality attributes, according to a new FDA draft guidance.

“In some cases, results from in-process controls can be used in lieu of finished-product testing,” the draft says. “This approach, however, should be supported with data that demonstrate a clear relationship between in-process testing and the critical quality attributes of the finished product.”

The guidance, “Coronary Drug-Eluting Stents — Nonclinical and Clinical Studies,” was released last month and is intended to clarify a variety of issues associated with developing such products, including the characterization of the drug substance and the chemical, physical and mechanical properties of the stents, the FDA says.

Although the guidance calls for finished-product testing to be performed on every batch after packaging and sterilization, traditional off-line end-product testing may not be necessary if the firm demonstrates product knowledge and process understanding and implements control processes routinely.

“The benefits of having an efficient and reliable process, with reduced reliance on end-product testing, include enhanced manufacturing efficiency and a reduced risk of producing a poor quality product. These concepts, when implemented, would be a significant advantage to stent manufacturers who typically produce small batch sizes,” the draft says.

Comments to the draft guidance are due July 25. The draft guidance can be accessed at www.fda.gov/OH
RMS/DOCKETS/98fr/FDA-2008-D-0180-gdl.pdf.