The challenge set by regulating authorities to vastly increase the levels of operator protection and to improve the sterility confidence levels associated with the manufacture of highly potent and parenteral sterile pharmaceutical products has led to substantial developments in the use of barrier isolation technology.

Isolation technology represents an alternative to laminar flow technology and cleanroom construction as a means of effectively (and at relatively low cost) achieving control over potent product containment and aseptic environments.

Sterile Compounds

It is generally accepted that people are a major source of contamination in the product preparation environment. Studies have shown that by removing personnel from the area in which aseptic manipulation takes place, increased sterility assurance levels are achieved.
The above concept forms the fundamental premise behind barrier/isolation technology. This technology was first used in the nuclear industry over forty years ago. Since that time electronics and pharmaceutical manufacturers have actively pursued the applications of this technology due to its performance and cost effectiveness. In the past few years within Europe, barrier/isolation technology has been introduced into the hospital pharmacy markets as well.
The barrier/isolation workstation for sterile drug preparation is a closed environment that uses solid stainless steel walls rather than air movement (clean rooms) to create a critical zone for product handling. The area is completely contained, offering protection to both the pharmacist and the product. The solid barrier also eliminates the procedural requirements of a "set back" and the need to place materials within the work zone in a manner that does not block the laminar flow. This freedom of placement allows more efficient work flow and productivity equal to or exceeding traditional hoods.

A HEPA filtration system is also used to condition both entering and exiting air to remove initial particles and particles that may be generated by the materials being used in the unit. Because the air filtration system of the unit is not being used to provide a barrier, high velocity is not needed, thereby reducing energy cost, noise levels, and heat loads. In many cases, the air is recirculated within the unit; in addition, a small quantity of air is discharged to maintain a pressure differential between the interior of the unit and the environment in which it is located. This pressure differential is used as a back-up if the security of the system is breached.

When product protection is the highest priority, the pressure differential can be positive; or, as in the case of operator protection on highest priority, the pressure differential is negative.

To take the environment to a sterile stage the closed mini environment of the barrier / isolation system can be sterilised using a gas, which will enable a log 6 kill to be achieved within the environment easily, thus vastly reducing any risk of false positive results in product sterility levels.

Potent Compounds

Choosing the correct type of containment equipment is essential to afford the operator and product the best possible protection. ACE / Bectochem have developed a simple 4-step procedure, which permits the quick and effective evaluation of the key factors which drive the need for

The Selection of the correct exposure potential (Or how much dust the operator will generate in carrying out the task in question) of the product is dependant on a number of factors:-

Material form (Dustiness Potential)
High – Fine light powders with dust cloud potential
Med – Granular or crystalline, visible dust, settles quickly.
Low – Pellets or non-friable solids

Duration of Task
Short term – A task durationof <30 mins is considered short
Long term – >30 mins or longer

Scale of operation
Small scale – Lab Scale / Pilot plant – (gms to Kg)
Medium Scale – (10 – 100Kgs)
Large Scale – (>100Kgs)

We can interpolate the results from steps 1 and 2 into the Containment Strategy Table below as a guide to the correct type of Containment equipment to be used.