Open RABS, Closed RABS and Isolators: Focus on Energy Savings • Pharma • IMA Group

Open RABS

RABS means Reduced Access Barrier System, it is a rigid protection made of transparent walls (polycarbonate or glass), equipped with an adequate number of glove flanges and gloves. It is installed on top of the filling and/or capping machines, separating them from the surrounding area.

Gloves must be positioned in order to allow the operator to perform all operations inside the machine, such as cleaning, caps/stoppers loading, vials removal, etc. so that these can be performed by operators without opening the protection walls.

The RABS can be PASSIVE or ACTIVE type.

PASSIVE means that it is NOT equipped with a dedicated air system, in that case the air flow inside the RABS should be generated externally, normally the Laminar Flow required in the filling and capping area is generated by fans and filters embedded in the false ceiling of the production room.

Both are considered OPEN because the air used for the laminar Flow is exhausted into the production room, without any control or filtration.

ACTIVE means that it is equipped with an independent air ventilation system, in that case the Laminar Flow required in the filling and capping area is generated by fans and filters that are parts of the RABS itself, then the air flow is partially independent by the air flow of the production room.
In both cases the area inside the RABS must be “A” class, and the surrounding area must be classifies as “B”.

Open RABS are useful to increase product protection, but they are not useful with toxic products, since they cannot offer any type of protection for the operator and the environment.

Advantages:

Easy to install, also on existing machines
Inexpensive
Easy to validate (air flow, air classification, doors interlocks)
Possibility to downgrade the production area to class B

Weaknesses:

Surrounding production area must be class B (with an Isolator it can be downgraded to the less expensive class C)
No operator protection, not useful with toxic products
Humidity and temperature inside the O-RABS is dependent by the production room conditions
There is no possibility to recycle the air used inside, saving HVAC energy consumption
No possibility to perform WIP cycles (Wash In Place)
No possibility to perform automatic decontamination cycles (for example with Vaporised Hydrogen Peroxide)

Closed-RABS

It is similar to an Active RABS (that includes the ventilation system) where the air is not exhausted into the production room but is recycled and/or exhausted via a controlled and well defined channel.

Considering that the system controls the full air flow (inlet and outlet) it allows a correct pressure control inside the system and it is suitable to be used with slightly toxic products.

Normally the classification of the air leak tightness of these systems is not carried out using the ISO 10648-2 standard, which is usually applied for isolators, since different solutions, with very different prices, are available on the market.

Due to the lack of leak tight certification these systems cannot not be used for highly toxic products.
Also these systems must assure a class A environment, the surrounding must be classified as B.

Advantages:

Easy to install, also on existing machines
Easy to validate (air flow, air classification, doors interlocks)
Possibility to downgrade the production area to class B
Humidity and temperature inside the Closed-RABS can be controlled adopting a dedicated HVAC
Possibility to recycle the air used inside, saving HVAC energy consumption

Weaknesses:

Surrounding production area must be class B (with an Isolator it can be downgraded to the less expensive class C)
Limited operator protection, not useful with highly toxic products
No possibility to perform WIP cycles (Wash In Place)
No possibility to perform automatic decontamination cycles (for example with Vaporised Hydrogen Peroxide)

Isolators

This is the state-of the-arte technology. It is a fully closed enclosure, equipped with a dedicated air circuit, where machines can be segregated.
It’s normally made of a stainless steel 316L structure, all windows are made of tempered glass, all inner walls are provided with rounded corners and there are no crevices in order to allow an easy and useful cleaning.

The classification of the air leak tightness of these systems is carried out following ISO 10648-2 standard, these tests give a real value of the system leakage, the achieved value will help to decide if we can use it with highly toxic products or not.

Using an international standard the comparison between different products become much more easy and serious.

Due to its leak free and easy to clean structure, the isolator can be cleaned with semiautomatic cycles (WIP) very useful to remove traces of contaminating products and can be decontaminated using agents in vapour phase as the Vaporized Hydrogen Peroxide, with fully automatic cycles.

Internally the isolator must assure a class A environment, due to its leak tight structure the surrounding production room can be classified as class C.

Complete vials/syringes filling lines for aseptic and/or toxic products are installed in several countries world-wide.

After a difficult start, they are day by day more accepted and EMEA and FDA are strongly suggesting the adoption of Isolators in any new production plant for aseptic products.

The advantages that they are offering in term of quality of the final product and in term of cost saving are absolutely demonstrated.

Also while the Isolator increases the complexity of the overall project, the selection of a supplier that can supply all the filling line as a “single source” can help to decrease engineering and validation costs, providing a standardized automation system and a centralized data collection.

Advantages:

Highest product protection
Possibility to downgrade the production area to class C
Humidity and temperature inside the Isolator can be controlled adopting a dedicated HVAC
Possibility to recycle the air used inside, saving HVAC energy consumption
Full operator protection, useful with highly toxic products
Possibility to perform WIP cycles (Wash In Place)
Possibility to perform automatic decontamination cycles (for example with Vaporised Hydrogen Peroxide
Enhanced automation, fully integration isolator-machine
Cost saving (do to the downgrade of the surrounding production area from class B to C)

Weaknesses:

It cannot be installed on existing machines, no upgrades posssible
Higher purchase cost

Operation Cost Savings

As described before the use of Isolation Technology allows the installation of a vial/syringe filling line for aseptic products in a production area classified as Class C, instead of a Class B that is requires when a Open RABS or a Closed RABS is used.

The downgrade of the classification of the production room allows the following Operation Cost savings:

Less quantity of air required by the production room
Less air sampling (particulate and microbiological)
Less time spent by operators to enter/exit the classified room
Less expensive gowning

In order to understand the saving generated by the reduction of the amount of air required by the production room.

This is a typical filling line composed by:

Accumulation table
Filling and stoppering
Nr.2 Freeze Dryer loading systems
Capping

If the line is installed in a conventional clean room (all class A), with this configuration it will requires: 68m2 of Class A (with unidirectional air flow)

The same filling line installed with Open or Closed RABS will requires Unidirectional air flow inside the RABS + 50cm of open unidirectional flow at the operator side.
With this configuration we need 20,6 m2 of class A (with unidirectional air flow) + 20,4 m2 of external unidirectional air flow (total 41m2) and 27 m2 of class B.

The same filling line installed with Isolator will requires Unidirectional air flow inside the Isolator ONLY.
With this configuration we need 20,6 m2 of class A (with unidirectional air flow) and 47,2 m2 of class C.

Comparing different installations of the same filling line, the results are:

The adoption of an Open or Closed RABS will allow to reduce the AIR Handling costs of approx 35%, compared with an installation in conventional clean room.
The adoption of an Isolator will allow to reduce the AIR Handling costs of approx 64%, compared with an installation in conventional clean room.
The adoption of an Isolator will allow to reduce the AIR Handling costs of approx 45%, compared with an installation with Open or Closed RABS.

These calculations do not take into consideration the possibility to re-circulate the air. This possibility is available for all the three configuration, but with higher efficiency with Isolator technology, due to its leak-free structure.

Open RABS

Closed-RABS

Isolators

Operation Cost Savings

ReliveAchema

Relive
Achema