GOSH selects Cherwell for support in excluding bacterial spores from aseptic compounding

Aseptic compounding at the GOSH Pharmacy Unit

Cherwell Laboratories, specialists in products for environmental monitoring and process validation, has recently supported the Great Ormond Street Hospital (GOSH) Pharmacy Unit in developing a new triple-wrapped prepared media product required to ensure the exclusion of bacterial spores during aseptic compounding validation. This has, in turn, increased workflow efficiency within the unit by reducing false compounder system failures, as well as disinfection steps and use of toxic sporicidal sprays.

Validation of compounding in the hospital pharmacy is essential for demonstrating that appropriate controls are in place to ensure asepsis of the process and the sterility of filled products (e.g. parenteral nutrition), and ultimately, to ensure patient safety. In order to monitor the aseptic liquid transfer technique of compounder operators, GOSH routinely undertakes aseptic process simulation validation (media fill simulations) using tryptic soy broth (TSB). Following a series of media fill simulation failures by multiple operators, due to the contamination of filled TSB units with Bacillus species, an investigation to identify the cause was conducted by GOSH.

This investigation found that the contamination was not attributable to operator competency, as they had strictly adhered to NHS aseptic transfer process guidance [1].
The contamination source was ultimately identified to originate from the TSB medium bottle surfaces following storage in an uncontrolled environment.  No bacteria were recovered from the surface of large volume licensed medicinal products, confirming that risk of spore contamination was during media fill validation and not actual medicine compounding.

GOSH sought an alternative microbiological media supplier to develop a way of ensuring the TSB units for aseptic process simulation validation were sterile, and Cherwell Laboratories were invited to collaborate with GOSH on this project. To remedy the situation, Cherwell developed a sterile, triple packaged TSB product in line with Royal Pharmaceutical Society recommendations [2]. GOSH Pharmacists found this prototype was easy to use and removed the risk of spore contamination of the medium prior to compounder validation, thereby eliminating false results and ultimately increasing workflow efficiency in the Pharmacy Unit.

Following the collaboration, GOSH and Cherwell have jointly published a white paper and scientific poster detailing the investigation and development of the new multilayer packaging of bacteriological medium to prevent spore contamination prior to compounder validation. Both were presented at the recent Clinical Pharmacy Congress and are now available to download from Cherwell’s website.

References:

1 NHS Pharmaceutical Micro Protocols Group. 2015. Guidance for Aseptic Transfer Processes in the NHS: Addressing Sporicidal Issues.
2 Royal Pharmaceutical Society and the NHS Pharmaceutical Quality Assurance Committee. 2015. Quality assurance of aseptic preparation services (QAAPS).