Medical Design Briefs - June 2023 - 8

Sponsored Content
INSIDE STORY
Many factors can affect the validation of your sterilization process, from the manufacturing environment
to the chosen sterilization method and even your packaging design. To find out more
about sterile product development and registration, MDB recently spoke with Elizabeth Sydnor,
Director of Microbiology of Eurofins Medical Device Testing (Lancaster, PA).
MDB: How do you determine if you need sterility testing per
USP <71> or ISO 11737-2?
Sydnor: USP <71> is the compendia
method that is widely applicable to
sterile pharmaceutical formulations,
medical devices, and radiopharmaceuticals,
whereas ISO 11737-2 is applicable
to the validation of sterile medical devices.
All sterility testing is done under
the premise of USP <71>, but there are
different requirements for performing
the test of sterility depending on your
product type and the intended use.
MDB: How long does it take for a sterilization validation to
be completed?
Sydnor: There are many factors that can impact completing a
sterilization validation, such as the complexity of the device,
number of samples available, and the sterilization modality to
name a few. However, most validations can be completed in 12
weeks from the time the product is received. This time frame is
not from the beginning of the project (design phase) to the end.
This typically includes bioburden testing, sterilization cycles,
sterility testing, and summary report writing.
MDB: If you find that you have high bioburden, but your sterilization
process is limited, what are your recommendations
for reducing bioburden?
Sydnor: It is important to collaborate with a sterility assurance
group to evaluate the existing manufacturing process. A manufacturing
process risk assessment would help determine the
potential bioburden challenges that are at each step of the process
and what could be adversely affecting the final bioburden
on the device. For instance, if we were doing gamma radiation,
and the process requires less than 1,000 colony forming units
be on the part, then it's important to understand what the
bioburden levels are on the device throughout the manufacturing
process and to determine if mitigation is necessary.
MDB: How do you define what type of cleanroom classification
is needed for a product?
Sydnor: Cleanrooms are great way to manage contamination
controls in critical environments (coating lines, final packaging,
aseptic filling, etc.). The classification of the cleanroom will be
dependent on the desired process and product. It is helpful to
have a collaborative team in the early stages of development to
understand the process and bioburden challenges from an endto-end
perspective. You need to understand what the microbial
limits are for the sterilization method to help support and identify
the risk throughout the process that could lead to higher
bioburden on the product. The lower the bioburden needs to be
to meet your sterilization validation requirements, the tighter
the classification will be and the controls within the room.
MDB: Why is the bioburden so impactful to the sterilization
validation?
Sydnor: According to ISO 11137 part 1, in order to establish the
sterilization dose needed to achieve the desired sterility assurance
level (SAL), a manufacturer should know the number and/
or the resistance to radiation of the bioburden. A laboratory will
perform a standard bioburden test to understand the naturally
occurring bioburden or the microbial load of your product. The
results are calculated to provide an average bioburden value,
which is then used in accordance with ISO 11137-2 to calculate
the minimum dose needed to achieve the desired SAL. Another
approach is to use a VD max method; however, the manufacturer
must have evidence that this method can achieve the
requirements for sterility.
MDB: How often are you required to check the classification
of the cleanroom?
Sydnor: During the validation of your cleanroom, a risk assessment
should be used to determine how often recertification of
critical parameters are assessed. If structural changes occur or
elevated bioburden is being recovered during routine testing, that
could be an indication that the existing validation should be reviewed.
Generally, any changes to a validated cleanroom should be
assessed due to the impact this could have on your final product.
MDB: If using biological indicators (BI), should it be packed
in the same packaging as the product?
Sydnor: Yes, for some sterilization validations, such as EO, part of
the evaluation will be assessing the location of your BIs. An internal
process challenge device (iPCD) is located within the product
or product load and is representative of the product, whereas an
ePCD is external to the load and is used as a control by the sterilizer
during the sterilization process. An iPCD is used to get an
indication of the time that it will take to achieve the desired SAL.
Several factors can impact the placement and results of the BI,
such as the packaging material, load configuration, and density.
To find out more about Eurofins Medical Device Testing, visit
www.eurofins.com/medical-device.
8
www.medicaldesignbriefs.com
Medical Design Briefs, June 2023

http://info.hotims.com/84480-757 http://www.medicaldesignbriefs.com

Medical Design Briefs - June 2023

Table of Contents for the Digital Edition of Medical Design Briefs - June 2023