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Medical Device Ethylene
Oxide (ETO/EO) Sterilization: Validation and other
challenges
For many medical devices, sterilization
with ethylene oxide may be the only method that
effectively sterilizes and does not damage the device
during the sterilization process. Medical devices made
from certain polymers (plastic or resin), metals, or
glass, or that have multiple layers of packaging or
hard-to-reach places (for example, catheters) are likely
to be sterilized with ethylene oxide.
ISO 11135 describes requirements that, if
met, will provide an ethylene oxide sterilization process
intended to sterilize medical devices, which has
appropriate microbicidal activity. Furthermore, compliance
with the requirements ensures that validations conducted
following this International Standard will provide
products that meet the defined requirements for sterile
products with a high degree of confidence.
The globally harmonized standard, that
provides guidance for completing such a validation is
ANSI/AAMI/ISO 11135:2014, “Sterilization of health care
products – Ethylene oxide – Requirements for development,
validation, and routine control of a sterilization process
for medical devices”.
Amendment 1: Revision of Annex E, Single
batch release (ISO 11135:2014/Amd 1:2018). This document
modifies EN ISO 11135:2014 with a revised European
Foreword and European Annexes ZA, ZB and ZC, and
additional European Annexes ZD and ZE as per MDR 1975/745.
Challenges in carrying out special
processes:
The standards for quality management
systems recognize that, for certain processes used in
manufacturing or reprocessing, the effectiveness of the
process cannot be fully verified by subsequent inspection
and testing of the product. Sterilization is an example of
such a process. For this reason, sterilization processes
are validated for use, the performance of the
sterilization process monitored routinely, and the
equipment maintained.
Since process is defined as a special
process; it needs to be operated by qualified operators as
per SOP guidelines, operators need to be well trained by
qualified personnel in the EO Sterilization process and
operating EO Sterilizers.
Exposure to a properly validated,
accurately controlled sterilization process is not the
only factor associated with the provision of reliable
assurance that the product is sterile and, in this regard,
suitable for its intended use.
Attention is therefore given to number of
considerations including:
• — the microbiological status of incoming
raw materials and/or components.
• — the validation and routine control of any cleaning and
disinfection procedures used on the product.
• — the control of the environment in which the product is
manufactured or reprocessed, assembled and packaged.
• — the control of equipment and processes.
• — the control of personnel and their hygiene.
• — the manner and materials in which the product is
packaged.
• — the conditions under which product is stored.
Here we have attempted to give an overall
view of what is equipment and process validation and steps
involved like DQ, IQ, OQ & PQ. Specifically for Ethylene
Oxide (EO) sterilization.
• An Ethylene Oxide (EO) Sterilization
Validation is designed to assist the manufacturer in the
development of a sterilization process that delivers the
appropriate sterility assurance level and ensures
repeatability for each product type developed.
Describing detailed processes,
documentation and re-validation will require much bigger
platform.
So, queries in implementation,
interpretation and report preparation may be addressed to
the author. We will make best efforts to resolve them.
Validation
EtO Sterilization is a low-temperature
process (typically between 37 and 63°C) that uses Ethylene
Oxide gas to reduce the level of infectious agents. EtO is
used in gas form and is usually mixed
with other substances, such as CO2 or
steam. It is mainly used for products that cannot
withstand the heat of typical autoclave sterilization such
as plastic. The main physical parameters to be monitored
are temperature and relative humidity. |
