Standard Guide for Coating Inspection and Acute Particulate Characterization of Coated Drug-Eluting Vascular Stent Systems

Abstract

5.1 The shedding of the coating from a vascular stent can alter its clinical safety and/or therapeutic benefit. Clinical performance (for example, drug elution) may be affected by particulate generation from the coated stent system and coating defects. This document provides guidance for coating inspection and acute particulate characterization of drug-eluting vascular stents. Information about the potential for shedding can be gained during bench testing. The general guidelines presented here may be used for writing detailed protocols for specific products at the various stages of the product development process. Such testing may be performed during device development, design validation testing, lot-release testing, and/or stability testing, although different requirements may apply at each stage. These suggested methods may represent a reasonable simulation of clinical usage. When establishing the coating inspection and acute particulate characterization testing conditions, the current clinical usage/practice (for example, post-dilation, overlapping stents) and the instructions for use (IFU), as applicable, should be considered. While methods for chronic particulate characterization and coating inspection have not been established, these suggested methods may be helpful in the development of chronic methods. Testing in accordance with recommendations in this guide will generate data that may lead to further improvements in the method and its validation, as well as possible advancements in device design and performance. See also FDA Guidance for Industry and FDA Staff and AAMI TIR42:2010.