PDA Letter Article

Regulators, USP Taking a Close Look at Visual Inspection

by John Shabushnig, PhD, Insight Pharma Consulting, and Markus Lankers, PhD, rap.ID Particle Systems GmbH

The visual inspection process is a critical step in the reliable supply of high-quality injectable medicines. It is required by regulatory authorities and specified in various international pharmacopeias. This important step also provides information on process performance and informs where and how to improve the manufacturing process. Yet there continue to be challenges in this area as evidenced by persistent drug product recalls due to particulate matter. In addition, in the first few months of this year, the US FDA released two Warning Letters on visual inspection issues.

Visual Inspection

For many years, the requirements for visual inspection have been ambiguous, with little direct guidance on how to inspect and what acceptance criteria to apply to the inspection process. This has resulted in a wide range of inspection practices as evidenced by a PDA survey on visual inspection conducted in 2014. This situation has improved with the release of USP <790> Visible Particulates in Injections in August 2014 and USP <1790> Visual Inspection of Injections in March 2017 (1). PDA is also completing a technical report to provide guidance on difficult-to- inspect products, such as lyophilized powders, strongly colored solutions, and those packaged in amber containers.

Since 2000, PDA has held the Visual Inspection Forum each year to discuss new technical and regulatory developments in this field. It alternates between the United States and Europe; this year’s meeting will be held in Bethesda, Md. The meeting provides a forum to present and discuss new developments in the field of visual inspection, including a basic understanding of the sampling and inspection process, special aspects of biotech products, the identification, risk assessment, and control of particles, and the contribution of packaging materials to these observed particles.

This is an excellent opportunity to learn more about visual inspection and to discuss inspection challenges with colleagues and experts.


  1. U.S. Pharmacopeia. General Chapters. USP39– NF34. Rockville, MD : 2016.

Learn more about the 2017 PDA Visual Inspection Forum and related PDA Education courses.

2017 Visual Inspection Forum