BFS is considered ‘advanced aseptic processing’ because it greatly reduces the two main causes of potential contamination in sterile filling.
First, there are no components that need to be washed and sterilized that are a potential source of contamination. In traditional BFS there are 2 primary input materials: polymer resin which is tested for low bioburden before use and is then heated which adds to the sanitation. The second is the drug or vaccine product which is controlled in a conventional way.
The second major cause of contamination in filling operations is interventions by operators. Traditional filling processes are especially vulnerable to this kind of contamination during processes like bottle or vial filling where the tops of the containers are open in the filling area.
In the rotary BFS machines, filling is a closed process. The filling takes place inside the parison which is filled with sterile air. This area is considered a class 5-ISO environment. This means the potential for the surrounding area and the operators that approach the machine to contaminate the filling process is significantly reduced.