Microbial Ingress Testing
At Wickham Laboratories, we regularly perform microbial ingress testing for medical device manufacturers, particularly at the product development stage. Medical devices with closure systems (sterile product packaging) must be shown to have maintained microbiological integrity until used, as part of quality control on the device. It is important to investigate the integrity of sterile packaging (e.g. syringes) throughout the life cycle of packaging from design and development, through shelf-life studies, and in routine manufacturing.
There would also be a need to re-verify these claims upon any change to the design, manufacturing and sterilisation of the package or device in question. The testing can be conducted through physical or microbiological means.
An example of a common project for us would be ingress testing on syringes with a luer lock closure. These would be tested by filling the syringe with sterile Tryptone Soya Broth (TSB), produced by our own in-house media preparation facility, and then refitting the luer lock cap. A number of syringes would then be submerged into an actively growing culture of Brevundimonas diminuta (a non-lactose-fermenting environmental Gram-negative bacilli) for seven days to assess device integrity.
After the seven day assessment period has passed, the syringes are removed and observed for signs of microbial ingress. This is determined by the turbidity of the media used in the test. Breached controls are usually included to demonstrate the high motility of the organisms and prove that they could gain access if there were any opening in the seal.
We are pleased to be able to accommodate many types of closure systems, and will work with you to design the most effective method of testing your particular device.