ChargePoint’s microbiological study of aseptic transfer of vial stoppers using its split butterfly valve
The test was carried out by Skan. The AseptiSafe spilt butterfly valve is said to have a number of practical advantages over existing transfer techniques although for years lacked the microbiological data to support its use. This study aims to gather this data by means of qualifying the technology.
The ChargePoint butterfly valve consists of half ports – an active and a passive. During the operation, the passive is docked to the active port in such a manner that the previously
exposed surfaces of both ports are locked against each other. In this way, two different controlled environments (class C and class A, for example) should be kept separated, and an aseptic transfer of material should be assured through the valve.
This study investigates investigate its suitability to
achieve an aseptic transfer of material, in this case vial stoppers, through the valve keeping controlled environments separate and free form migration of microbiological contamination
Test protocol
The practical qualification involved challenging the split butterfly valve with class C bioburden (20-25 spores per 2826 mm2, i.e. area of a standard contact agar plate), using Geobacillus stearothermophilus spores, and transfer vial
stoppers through the valve. The transferred stoppers where then incubated in a growth medium to detect any bacterial growth. The microbial study was further divided into two
test parts (A and B).
In the test (B), class-C bioburden exposed surfaces of the valve (valve plates) was disinfected with 6 % H2O2 prior to the assembly of the valve. Whereas, in test (A), no prior decontamination of class-C exposed surfaces was carried out. For each test, the experiment was conducted in triplicates using three valves with multiple make and breaks under identical experimental conditions in a pharmaceutical sterility isolator (PSI).
Figure 1: Loaded isolator chamber and airlock
Figure 2: Example of bulk transfer of stoppers in IBC form autoclave to filling line via split valve at each stage (not part of this study)
Results
- Bacterial growth was observed in positive
- controls for both parts of the test (A and B)
- Negative controls remained clear.
- No turbidity (implying no bacterial growth) was observed in any of the test containers.
This means that non of the contamination inoculated onto the faces of the discs had managed to migrate onto the stoppers during the transfer.
Discussion
With the results of this study it could be clearly demonstrated that aseptic transfer of stoppers through the valve assembly can be achieved in routine pharmaceutical processes wherever required.
Figure 3: inoculation of valve plates with class C bioburden
Aseptisafe benefits
- Ergonomically, docking and actuation is unhindered by gloveport or gloves. (operated from outside the enclosure)
- No intervention into the line and less operations to perform the transfer.
- No intervention means less risk (particle generation and damage)
- No intervention means no additional gloveports to access the device internally.
- No intervention means no additional cost from the RABs / isolator supplier (glass /port/glove).
- No opening parts inside the line means no disturbance to the laminar flow inside the aseptic core and no particle generation over the stopper bowl.
- Passive can be reused after transfer.Autoclaved or SIP if mounted to a stopper transfer vessel.
- Contamination free transfer.