The use of Vaporized Hydrogen Peroxide (VHP) in aseptic transfers

28 September 2016

The demand for advanced pharmaceuticals to meet the needs of the evolving human race has brought about the necessity for biotechnology innovation.

Vaccines are widely believed to hold the key to the burgeoning AMR crisis and a failure to act to invent technologies to speed up the manufacture of vital drugs could be catastrophic.

Quality of the end product has always been paramount and efficiency of the process is equally as important.

As the pressures of modern living on the scientific, medical and technological sectors grows, maintaining the highest standards is more important than ever.

The techniques to ensure sterility consist of high classification cleanrooms and barrier or isolator technology, along with sterilisation or decontamination processes to ensure the product and technology in critical manufacturing areas are kept at the required sterility assurance level (SAL).

A containment device widely used within the pharmaceutical industry to achieve product transfer is the split butterfly valve (SBV), which was developed more than 20 years ago.

The widespread use of SBVs within the manufacturing process has evolved from a part in the transfer of highly potent powders to a major role in the transfer of sterile ingredients.

As a result of the utilisation of SBVs and the ever-growing demands on manufacturing, ChargePoint Technology have created a device that is revolutionising the aseptic transfer market.

The fundamental feature of the AseptiSafe SBV is the two halves, namely the Active (Alpha) unit and the Passive (Beta) unit. Each half consists of half of the ‘butterfly’ disc which is sealed against the main body via an elastomeric seal to create the sterile barrier.

In operation, the two disc halves are locked in place to form a single sealed unit and the previously exposed interfaces are then sealed together.

The active unit is the driving half of the valve and once operated, either manually or automatically, the disc will open to allow the transfer of material through the valve with the valve closed unlocked and undocked once the transfer has taken place.

The area of concern exists with the small area where the outer circumferences of the disc interfaces (that are exposed to the room environment) seal together and rotate into the open critical area.

This is known as the ‘ring of concern’ which is common in any aseptic transfer device and the highly specialised SBV created by ChargePoint Technology – called the AseptiSafe bio – uses a technique to eliminate that concern and, in fact, ensure the highest standards of SAL are met.

Eliminating the Ring and Area of Concern on Split Butterfly Aseptic Transfer Valves from ChargePoint Technology on Vimeo.

This new approach involves partially docking the two disc faces creating a sealed chamber which can be bio decontaminated prior to final docking. The active portion of the valve is designed in a unique way: the sides of the valve body form walls, when the passive section is introduced, a sealed chamber is created, allowing a matchless decontamination process to take place.

ChargePoint Technology have taken this a step further with the selection of H2O2 -hydrogen peroxide gas as the decontamination media.

H2O2 has for the past 20 years given fast and safe decontamination to areas that may be contaminated with bacteria.

In the 1980s, after almost a century of using aqueous Hydrogen Peroxide for disinfecting heat sensitive medical devices and surgical apparatuses, the American Sterilizer Company, now STERIS, discovered H202 has a quicker sporicidal time when in vapour form in smaller concentrations.

As well as Hydrogen Peroxide’s natural power, it has been used as an ingredient to solve everything from teeth whitening, contact lens cleaning and mouthwash, tackling acne and even cleaning aquariums.

Christian Dunne, Global Sales Manager for ChargePoint Technology, said: “Small droplets are dropped onto a hot plate and they are vaporised and blown into an air stream and into a space between our passive and active just before the valve docks and that’s when the elimination of bacteria in the area happens.

“When you have a potentially ‘dirty’ room, two faces are brought together and that traps the un-classified air. If you open the valve up there is risk contamination from the air can contaminate the product.

“Once we have created this chamber what we do is propel the Hydrogen Peroxide gas through and decontaminate the space. We prove its efficacy by putting biological indicators inside to validate the process.

“We then take the indicator spores and see if we can grow something from it, if we can’t then we know the process has worked and the bacteria has been killed, the area is contaminant free proving our patented system works.

During docking a sensor on the active portion of the valve identifies that the passive valve and transfer container are located in the partially docked position.

Gassing valves located at either side of the valve then open and allow the gas to be transferred through the sealed chamber bio-decontaminating the internal surfaces of this area.

This decontamination process goes through four distinct phases to ensure that not only has the space been decontaminated but the H2O2 gas has been fully removed.

The timed sequence of the process is:

  • Setting the humidity level for the introduction of VHP/VHPV (Dehumidification/Conditioning)

  • Introduction of VHP/HPV (Conditioning/Gassing)

  • Bio-decontamination/Dwell period. Where biological deactivation occurs.

  • Aeration. Removal of VHP/HPV to less than 1PPM. This time includes any out-gassing from material.

The times taken for this process vary between six and 30 minutes dependent on the gassing system utilised, chosen to ensure the effectiveness on the size of space which is gassed.

For a bio-decontamination cycle time, the timeframe is considered extremely fast compared to the conventional airlock approach to transfer into the aseptic core, which would typically be in the region of 30 minutes to one hour due to the surface area and volume being transported.

The applications for this type of sealed transfer are varied, although this system is now being successfully utilised in the product transfer for non-terminally sterilised products, adding bulk powders to formulation vessels, and also direct from process dryers into immediate containers and then into filling lines.

Manufacturers are benefiting from a closed handling method that not only achieves the required SAL along with a reduction or elimination of manual intervention but also the opportunity to reduce the resource associated with cleaning and validating large volume areas.

This is done by utilising a compact and efficient split valve system that is also capable of ensuring high level protection while handling toxic ingredients that pose risk to operators.

Comments (1)

  • Whether you have 8" VHP sterilisable valves available in stock for aseptic processing?

    Vijay Padalkar

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