FAQ on Media fill
What is Media Fill?
The validation of aseptic processing operation using microbiological growth nutrient medium in place of product is called “Media fill” or “Process simulation”. The nutrient medium is exposed to product contact surfaces of equipment, container surfaces, critical environment, and process manipulations to closely simulate the same exposure that the product undergoes during various stages of manufacturing.
Media fills plays a pivotal role in establishing the sterility assurance for sterile drugs.
Inert gases are not used in Media fill studies Why?
Inert gases will prevent the growth of aerobic micro organisms .Therefore for in process simulations sterile filtered air should be used instead of Inert gases. Important fact is that the gas to be used in the media fill should not inhibit contamination if there are any. Such a scenario can turn out to be disastrous, wherein passing of media fill could have been actually due to the fact of growth inhibition of the organism due to the type of gas purged and not necessarily the media fill is a success. As an example, if your product manufacturing employs Nitrogen or Argon purging, for media fills you must choose to purge the broth with compressed air. This way you ensure that contamination if any due to wrong aseptic practices / interventions etc. are truly captured. The final outcome of media fills in such cases will give the true picture.
What is the re validation criterion for media fills?
Apart from routine schedule, media fills to performed in case of
· Changes in the critical process, facility and major equipment modification
· Abnormalities in environmental monitoring results
· Sterility test failures (If applicable, based on the outcome of Investigation)
· After major construction activities such as demolition of adjacent to or surrounding controlled areas.
· Line Configuration changes
· Extended shut down (if the line is idle for six months three media fill runs and the line is idle for three months one media fill run shall be performed before starting the production)
· Containers/ Closure changes
· Initiation of additional production shifts
· After failure of media fill, if root cause is not identified three media fill runs and if root cause is identified one media fill run has to be performed.
What is the incubation period of media filled containers?
Media Filled Containers shall be incubated for not less than 14 days. The filled Containers shall be incubated at 20-25°C in inverted position for 7 days and at 30-35°C in upright position for further 7 days.
What is the pass or fail criteria for media fill?
When filling fewer than 5000 units, no contaminated units should be detected.
When filling 5000–10 000 units:
— one contaminated unit should result in an investigation, including consideration of a repeat media fill;
— two contaminated units are considered cause for revalidation following investigation ;
When filling more than 10 000 units:
— one contaminated unit should result in an investigation;
— two contaminated units are considered cause for re validation following investigation.