Rapid Sterility Test Considerations

Sponsored by Nelson Labs

In this interview, Nina Moreno, a global segment director for sterility assurance at Nelson Labs, discusses the evolving role of rapid sterility testing (RST) in the pharmaceutical industry. With more than 23 years of experience and active involvement in industry groups, Moreno explains how RST offers a faster and more objective alternative to traditional compendial sterility tests.

Rapid sterility testing is supported by several regulatory frameworks. Multiple RST approaches are available—such as respiration-based methods, solid-phase cytometry, and nucleic acid amplification—while Nelson Labs employs ATP bioluminescence technology. Implementation requires product-specific validation, including method suitability testing with an expanded panel of organisms and sample interference studies to confirm that the product does not adversely affect test performance.

A primary advantage of RST is the significantly shorter time to release, often reducing the testing timeline to approximately six days. This is especially beneficial for short shelf-life products and formulations that are inherently turbid. Because RST relies on objective detection rather than visual assessment of turbidity, it eliminates the need for the additional four-day media transfer incubation typically required for cloudy products. Moreno also notes certain limitations: products with high levels of endogenous ATP may interfere with ATP-based assays, and filtration-based methods are not suitable for products that cannot be filtered. To address these challenges, Nelson Labs offers a direct inoculation option for its ATP-based sterility testing.

Looking ahead, the regulatory outlook for RST continues to improve, with growing acceptance and clearer guidance. Recent additions to the USP, including chapters <72> and <73>, further support the use of rapid microbiological methods, particularly in time-sensitive manufacturing scenarios. In response to increasing demand, Nelson Labs is expanding its cleanroom and isolator capacity in Salt Lake City to provide redundant equipment and maintain efficient turnaround times without extended testing backlogs.