Tag Archives: growth media

Environmental monitoring: viable particles

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The Question posed on LinkedIn.

“Hi all, I would like to ask you about how to perform cleanroom microbiological environmental monitoring. Is it clearly defined in guides?
TSA and Sab at different temperatures or only TSA? If only one TSA plate, do you incubate at 20-25ºC and then at 30-35ºC, or only at one temperature?
Do you performe growth promotion test in same conditions?
Thank you for your comments!”

My advice:

USP <791> Environmental Monitoring Program Design and Application

USP <1116> Microbiological Control and Monitoring of Aseptic Processing Environments states “….time & incubation temps is made once…media have been selected. Typically…22.5 ± 2.5 and 32.5 ± 2.5…incubation time of 72 & 48 hrs, respectively. Sterilization processes used to prepare growth media for the environmental program should be validated &…media should be examined for sterility & for growth promotion as indicated under Sterility Tests 71. In addition, for the Growth Promotion test, representative microflora isolated from the controlled environment or ATCC strain preparations of these isolates may also be used to test media. Media must be able to support growth when inoculated with less than 100 colony-forming units (cfu) of the challenge organisms.”

So, pick your media. Test it. After that, validate your sampling recovery methods.

Clean Room Grade for change room in Sterile Area

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The Question posed on LinkedIn.

“Please let me guide or give recommendations, what will be grade of change room just opening in Aseptic filling area. Please mention reference also.”

My advice:

PE 009-12 (Annexes) 2015.

Annex 1 states:
“Changing rooms should be designed as airlocks and used to provide physical separation of the different stages of changing and so minimise microbial and particulate contamination of protective clothing. They should be flushed effectively with filtered air. The final stage of the changing room should, in the at-rest state, be the same grade as the area into which it leads.”

So, what Grade is the filling facility? That is the grade you should validate your changing room/airlock to be.

A google search will find you the relevant PIC/S PDF.

Followup comment

You can download all the PIC/S documentation here: http://www.picscheme.org/publication.php

Disinfection of active air-samplers

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The Question posed on LinkedIn.

Avoiding cross-contamination when using microbiological air-samplers is a key activity. But how effective is the procedure? To evaluate this, Tim Sandle and Ravikrishna Satyada have written a paper based on test data…link to Disinfection of active-air samplers.

My comment:

For filling rooms, I’d always use a double wrapped autoclaved sampling head. For ancillary rooms where the risk to the product was lower, IPA was used rather than a new head.

With internal sanitation of air samplers, when I’ve validated units like the Merck MAS100 and Biomeriux RSC+, spraying with IPA was shown to be sufficient.

With regards of HEPA filtering the output airflow, smoke pencil studies showed laminar flow would take the air to the floor. Correct placement of the air samplers within the filling space and ensuring only samplers assigned to critical filling areas were used in critical filling areas would reduce the risk of cross contamination.

Good that you data showed effective sanitation and a lack (or low) cross contamination risk.

Dehydrated Culture Media used in “Media Fill”

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The Question posed on LinkedIn.

“Dehydrated Culture Media used in “Media Fill”. Does the powder specification need to be sterile (irradiated) or it can be sterilized by filtration (0.22µm) just after browth preparation in tank?”

My advice:

Your starting dehydrated media should meet your existing limits for raw materials with regards to microbial load.

If your standard procedure is to formulate your product in an ancillary room and sterile filter it on the way to the filling heads, then I would include this in your sterile media fill trials as it simulates your normal batch process.

A batch simulation with no interventions should demonstrate your filtration sterilises your “product”. Once that’s done, you can then incorporate interventions into your sterile media fill trials.