Abstract
Advanced technologies in both aseptic filling and environmental monitoring are coming together to improve the resilience and sterility assurance of aseptic processing. Continuous, real-time environmental monitoring using biofluorescent particle counters (BFPCs) to detect viable and nonviable particles during the aseptic filling process for injectable drugs is gaining traction as an accepted alternative to conventional methods such as active air sampling instruments. Evolving regulatory guidance, including EU Annex 1 guidelines, are increasingly recommending the adoption of isolator technology as well as continuous environmental monitoring during GMP processes, including technologies that offer real-time feedback during drug product manufacturing. Computational flow dynamics and airflow visualization studies are additional tools that support the design of equipment and determination of locations for environmental monitoring. The current nutrient culture media growth-based environmental monitoring, rooted in science from 150 years ago, is unable to keep pace with recent technological advances and the ability to immediately react to an out-of-control state. Here we examine the design of an isolator that eliminates human intervention and indirect product contact parts during aseptic fill finish operations and present computational fluid dynamics (CFD) studies verified by airflow visualization, along with the incorporation of BFPCs at critical areas. Also, we report the results of the interference study characterizing the baseline results for detection of total particles (nonviable plus viable) using a BFPC within a robotic gloveless isolator during dynamic and static operating conditions. The results of our study using BFPCs demonstrate that airflow in the robotic gloveless isolator provides protection of critical areas from contamination during the tub peeling process and that the stoppering process in this environment does not generate detectable particles. During dynamic conditions and material transfer, the study demonstrates the design of the robotic gloveless isolator prevents false positives from interfering with materials during normal operations.
- Aseptic filling
- Environmental Monitoring
- Biofluorescent particle counter
- BFPC
- Robotic gloveless isolator
- continuous monitoring
- Annex 1
- Isolator
- Received June 5, 2025.
- Revision received December 9, 2025.
- Revision received October 24, 2025.
- Accepted December 30, 2025.
- Copyright © 2026, Parenteral Drug Association
PDA members receive access to all articles published in the current year and previous volume year. Institutional subscribers received access to all content. Log in below to receive access to this article if you are either of these.
If you are neither or you are a PDA member trying to access an article outside of your membership license, then you must purchase access to this article (below). If you do not have a username or password for JPST, you will be required to create an account prior to purchasing.
Full issue PDFs are for PDA members only.
Note to pda.org users
The PDA and PDA bookstore websites (www.pda.org and www.pda.org/bookstore) are separate websites from the PDA JPST website. When you first join PDA, your initial UserID and Password are sent to HighWirePress to create your PDA JPST account. Subsequent UserrID and Password changes required at the PDA websites will not pass on to PDA JPST and vice versa. If you forget your PDA JPST UserID and/or Password, you can request help to retrieve UserID and reset Password below.






