Materials brought in and out of controlled environments is a major source of contamination.

THIS ARTICLE WILL LOOK AT WAYS TO reduce the initial bioburden on items passed into the cleanroom, so that contamination is minimized. This includes:

• Using the most effective disinfection technique
• Reducing the number of paper packed items
• Reducing the amount of packaging that needs to be disinfected, by bulk packing items such as syringes, needles, and waste bags
• Ensuring the disinfectant used stays sterile and does not cause contamination

Use Effective Disinfection Techniques
EU GMP (European Union Good Manufacturing Practices) Annexe 1 states that “The transfer of materials into and out of the unit is one of the greatest potential sources of contamination.” [1] The need for better transfer disinfection procedures has been highlighted by studies investigating the bioburden on items passed into pharmaceutical isolators. [2] This work showed that about 60% of items ready for transfer were contaminated with bacteria prior to disinfection.More significantly, 40% of items were contaminated with bacterial spores that would not be removedby spraying with alcohol alone (Table 1).

Table 1: Sample testing of items routinely used in isolators

Further work was then carried out to assess the effectiveness of different liquid disinfection techniques [2] (Table 2). Spraying and wiping was found to be the most effective method of transfer disinfection—especially against spores—because bacteria and spores can create a protective biofilm which needs to be removed by wipingso that the disinfectant comes into direct contact with the microorganisms.

Table 2: Validation of liquid disinfection techniques

Reducing Initial Bioburden
However, even if a hospital clean- room adopts good spray and wipe protocols, there are risks of high initial bioburden from certain types of packaging. For example, the paper in paper-backed items is porous so it is easily contaminatedand the uneven surface makes wiping less effective.

An effective solution is to use a sterile multi-pack that contains a quantity of sterile components, removing the need for individual packaging. The smooth polythene bag of a sterile multi-pack is easy to wipe and does not support the presence of bacteria inthe same way as paper.

Many components required in the cleanroom are difficult to spray and wipe, due to their small size or awkward shape. Again, the multi-pack bag is easier to wipe effectively.

Figure 1. Multipacks offer a wide range of components and quantities.

Reduce Particulates
Paper packaging also needs to be reduced within a cleanroom environment because it carries a high particulate load. The number of particles shed is so greatthat if you open 50 paper-backed syringes over a dark surface you can easily see the shed particles on the surface. By contrast, the polythene multi-pack bag virtuallyeliminates the shedding of particles on opening.