Newsletter_12-2022_EN

www.reinraum.de
NEWSLETTER
www.cleanroom-online.com Edition EN 12-2022 | Page 5/42
temperature and time.
Sometimes failures of re-validation can be attributed to using biological
indicators with much higher D-values than those used for the
initial validation (where the biological indicators used for the re-validation
have a far higher resistance compared with those used for the
initial qualification. This could occur, for example, if the initial qualification
was performed using a biological indicator with a D-value of 1.5
minutes and the re-qualification executed using a biological indicator
with a D-value of 3.0 minutes).
Issues can also arise due to changes to load patterns. How load
patterns are assessed such as mass compared with item complexity
and configuration, as with tubing.
One issue will be the requirement to more carefully assess the
quality of pure steam. There is also a materials piece, in that before
any sterilization process is adopted, the suitability for the product or
equipment need to be assessed to make sure it is suitable for the desired
sterilizing conditions.
Another factor is with the design of the load, as I’ve previously
mentioned. Other considerations for the validation design include
handling items of a shape where there is the potential for trapped air
(and thus difficulties with air removal). There are also items that may
not allow steam to penetrate and are thus hard to heat (such as filters,
check valves, and small tubing). Plus, there are items where there is
potential for condensate collection.
It is important to undertaken a careful evaluation, and to set an appropriate
maximum reprocessing time.
Conclusions
We would like to conclude this interview with a quote from the new
Annex 1.
§8.60 The items to be sterilized, other than products in sealed containers,
should be dry, wrapped in a material which allows removal
of air and penetration of steam and prevents recontamination after
sterilization. All loaded items should be dry upon removal from the
sterilizer. Load dryness should be confirmed by visual inspection as a
part of the sterilization process acceptance.
The choice of packaging systems becomes of utmost importance
for proper alignment with the requirements of the new Annex 1. Indeed,
as is clear from the text, and from the interview with Tim Sandle
himself, the success of the sterilization cycle depends on several factors
closely related to the selection of the packaging material: only a
low degree of particle release, an anti-microbial barrier of maximum
effectiveness, a bill that allows uniform steam penetration, and last
but not least tear and puncture resistance can ensure a proper autoclave
cycle.
Critical issues of washable products
How do you evaluate the use of washable products and what,
if any, critical issues do you see in this type of choice?
The key issue with washable products is with the number of times
they can be processed and what the impact of this is upon the life-time
of the item. Integrity issues and release of particles are two areas
of concern, along with other forms of structural weaknesses and discoloration.
This relates not only to the washing process but also to
sterilization – both are aggressive processes that can affect the material.
The choice of water and the type of sterilization process and the
parameters surrounding this represent important choices to be made,
in order to avoid damage and to extend the reprocessing cycle.
AM INSTRUMENTS
Via Isonzo, 1/C
IT 20812 Limbiate (MB)
Phone: +39 02 8728421
email: info@aminstruments.com
Internet: https://global.aminstruments.com/
Dr. Tim Sandle is a pharmaceutical microbiologist, science writer and
journalist. He is a chartered biologist and holds a first class honours
degree in Applied Biology; a Masters degree in education; and has a
doctorate from Keele University.
Interview by Cristina Masciola, AM Instruments
– Marketing & Communication Manager