Tim Sandle has written an article for European Pharmaceutical Review about improving assurance in relation to microbial bioburden assessments. This relates to the use of biocontainer bags, designed to reduce the chance of false positives occurring.
Assessment of microbial levels in (and on) samples is an important part of pharmaceutical process control. Samples are drawn from intermediate product at defined stages (ideally based on risk assessment) and these allow for the microbial levels to be tracked from upstream processing to downstream processing (with an expectation that the microbial levels decrease, or at least remain unchanged provided they are below an acceptable action level). For aseptically products, European guidelines require a certain bioburden to be met at the point that a bulk product passes through a sterilising grade filter.
Due to the relatively low specification – of 10 CFU/100mL – pharmaceutical manufacturers need to ensure that false positive results are avoided (as might arise from extraneous environmental contamination). False positives can result in batch rejection. A key innovation, in recent years, is the biocontainer sampling bag. This item of irradiated plastic is in keeping with moves towards single use, sterile processing technology.
The article examines the importance of bioburden testing, particularly in relation to aseptically filled products, together with the most important criteria for sampling bags.
Sandle, T. (2016) Improving microbiological assurance for bioburden tests, European Pharmaceutical Review, 21 (3): 41-44
Posted by Dr. Tim Sandle