Toxic Sterile Dispensing Isolator: one solution for powders that are both toxic & sterile

June 24, 2022

FPS has recently designed and manufactured an isolator designed to introduce up to 100kg of potent sterile API and dispense it in specific containers to be connected to the process equipment.

During the initial phase of listening to the customer’s needs, the different stages of the process were analyzed, from the introduction of the material into the airlock, to the decontamination cycle for both the airlock and the working chamber to ensure sterility during the operations, to the dispensing of the weighed material either into a rigid container through a split butterfly vale or into bags through a continuous liner port.

With this initial analysis completed, FPS pulled on almost two decades of experience in powder containment to design and build the system.

The main challenge of this project was the characteristics of this particular API powder, which was both toxic (OEL < 1µg/m3) and sterile. In addition, the installation room and isolator had to be classified according to the ATEX directive (II 2G external, II 2GD internal), and sterile conditions had to be ensured and monitored throughout the activities. Finally, the isolator control system and the installation monitoring system had to be interconnected.

The proposed design by FPS allows the decontamination system to ensure keeping the sterility first and then to protect the operators thanks to an adaptable control system that can switch from a positive (sterile) to a negative (toxic) pressure regime during specific process steps.

The advantages of this solution are many, particularly the adaptable control system guarantees both the API and the operator protection by switching from positive to negative pressure regime during specific phases:

  • Positive during the decontamination cycle and the dispensing activities
  • Negative during the final washing phase

Also the control system of the isolator is connected to the centralized monitoring system of the plant, so that the process and the alarms can be monitored in real time.

The split butterfly valve is connected to the vaporized hydrogen peroxide decontamination system to guarantee the sterility when the dispensed product is removed from the isolator

A drum lifter raises and lowers rigid containers to be connected to the isolator through the split butterfly valve The rapid transfer port is also used to introduce the cleaning tools at the end of the operations. In addition a special beta container is fitted with the connections to the washing medium and drying nitrogen lines so that no dedicated connection is required inside the working chamber.

” Finding a performance solution that reconciled the needs of a powder with toxic and sterile characteristics was an extremely stimulating challenge for FPS,” says Eng. Stefano Butti, Technical Sales Director. “At first it seemed impossible to create a system that could work at both regimes, and instead, thanks to our experience and the FPS team, we have created a single system customized for such special powders.”