| Colin Booth at Oxoid Limited, explores how aseptic processing demonstrates process control through simulation and monitoring
Increasingly, pharmaceutical companies are depending on aseptic techniques to ensure the sterility of products. As aseptic processing becomes more commonplace, it is important that we remember the significance of each individual aspect of control and how they relate to each other. This article discusses the roles of monitoring and process simulations in demonstrating aseptic process control.
Sterility is defined as the absence of microbial contaminants. Many products can be sterilised by heat or irradiation, but some are sensitive to such extremes and require aseptic processing to ensure the risks of microbial contamination are minimised, if not eliminated. Maintenance of aseptic conditions involves a careful balance of control measures, each of which must be individually validated and monitored. All are equally important; if a single system fails to do what is expected, it can result in loss of control for the entire process.
Some of the most significant processes used to eliminate the risk of microbial contamination in aseptic processing include:
- Designated cleanrooms and support areas
- Minimal human intervention – and, where it cannot be avoided, the training and qualification of employees and the use of suitable gowns and gloves for example
- HEPA filtered air – supplied under laminar flow to direct air flow away from critical steps, such as point-of-fill
- Positive air pressure – to minimise the movement of air into the cleanroom area
- Sterilisation of everything brought into the cleanroom – including steam sterilisation of vials and seals, and filter sterilisation of the final product, for example. The obvious exception to this rule is people – one of the most frequent sources of contamination! Since operators cannot be sterilised, every precaution must be taken to ensure that risks are minimised
- Cleaning, sanitisation and disinfection procedures
All of these processes must be validated and monitored to ensure they are working correctly. For example, air pressure and air flow should be monitored continuously against suitable alert and action levels to allow time to rectify a problem before any damage is done. The entire process should be supported by a thorough environmental monitoring programme and ultimately validated using process simulations or media fill trials (MFTs). |
