Media fill test: concrete implementation

According to the 2019 Best Practice Guidelines for Pharmaceutical Preparation, successfully completing a media fill test is required for pharmaceutical assistant qualification.
Our objective was to create a reproducible protocol that could be implemented in a hospital isolator.
Six areas of preliminary research were identified: guidelines, search engines, professional websites, exchanges with industrial actors and discussion with raw material suppliers. High-risk situations were selected in a “post-it mapping” meeting. Pharmacopeia, best practice manufacturing guidelines and the six selected posters were uninformative.
There are relatively few descriptions of how to simulate usual manufacturing procedures, identify the number of necessary preparations and implement microbiological culture. Our process was therefore mainly based on industrial experience, including identifying unfavourable conditions for culture and for controls, as well as simulating production steps with a trypcase soy broth. Operator validation kits adapted for a hospital setting and bacterial strains described by the European Pharmacopeia were acquired. We established the protocol for the use under aspirator of frozen Bacillus subtilis tablets. The working group identified three key events (basket changes, door opening and discontinuous production) and four key elements (reconstitution, use of refrigerated substances, a high number of vials and removal of solvent from dilution bags). Of the top 25, trastuzumab and rituximab bags as well as azacitidine syringes fulfil the criteria. The instructions given integrated the three high-risk situations. The test was computerised in order to provide production sheets. Two pharmaceutical assistants completed six preparations one Friday afternoon. One bag was sterilised in an isolator and sown with Bacillus subtilis. 72h positivity confirmed the innocuousness of hydrogen peroxide on trypcase soja broth in the bags. There was no clouding after 7 days at 22°C then 7 days at 32°C.
After being sown with Bacillus subtilis, clouding confirmed the fertility of each solution. Bacteriological testing of the gloves, the contact petri dishes and the sedimentation petri dishes were all negative.
Given a lack of bags, our simulation required certain adaptations to decrease costs. Daily cloud reading and sowing required a lab technician.
According to our scenario, a minimum of four months would be necessary to validate four assistants.
Our simulated media fill test conforms to usual standards and is feasible with a yearly cost of 4800 euros of consumables. Satisfactory training can be achieved with three procedures per person, integrated into routine practice.

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