Page 232 - Biomedical Engineering and Design Handbook Volume 2, Applications

STERILE MEDICAL DEVICE PACKAGE DEVELOPMENT 211

(e.g., IQ, OQ, PQ), which ensures that the package will perform in harmony with the product in a
consistent and safe manner. This is accomplished by developing a comprehensive plan that cannot
be simplified or short-circuited. Product engineering has realized that to accomplish the task of pack-
age process validation, the package system must be developed in tandem with the product develop-
ment. Otherwise, delays of 6 to 12 months could result while the package system is being validated.
The ISO 11607 standard provides guidance to assist medical device companies in developing sterile
medical device package systems that perform efficiently, safely, and effectively in the hands of the
caregiver. Remembering that the standard provides designers and manufacturers of medical devices
with a framework of laboratory tests and evaluations that can be used to qualify the overall perfor-
mance of the package, there are many means within this framework to achieve the end result.

7.8 SHELF-LIFE STUDIES

This part provides guidance for conducting accelerated aging or stability studies for medical device
packages. A distinction between accelerated aging and environmental challenging should be made
here. The ASTM Standard F1327, “Standard Terminology Relating to Barrier Materials for Medical
Packaging,” defines the two events as follows:

Accelerated aging—a technique to simulate the effects of time on a sterile barrier system or packaging sys-
tem by subjecting the packaging to elevated temperatures under conditions otherwise representative of con-
trolled environment storage conditions. The equivalent time is generally estimated by assuming the
degradation of packaging materials following the kinetics described by the Arrhenius reaction rate function.
Environmental challenging—the process of subjecting a sterile barrier system or package system to
extremes of temperature and/or humidity with the goal of determining sensitivities of the packaging sys-
tem to environmental stresses. In contrast to accelerated aging, environmental challenging often includes
conditions and/or transitions of temperature and humidity that equal or exceed those that can be encoun-
tered in a packaging system life cycle.

This part discusses the techniques used for accelerated aging while the environmental challenging
will be discussed in Sec. 7.9. The distinction in these environmental testing techniques is important
because for accelerated aging, the key is to choose a test temperature that does not damage the materi-
als from conditions that would not be expected to occur in real time or are outside of the recommended
use for the materials, but still “age” the materials in an accelerated manner; the purpose of environ-
mental challenging techniques is to asses package performance at the realistic extreme conditions pos-
sible in the package life cycle or to stress the packaging materials near or past its failure point.
Developers of medical device packaging have struggled for years to justify shelf-life claims and
establish expiration dating for packaged medical devices. Much has been published over the past
decade describing techniques for conducting accelerated aging programs. However, the theory of
accelerated aging is complex enough for homogeneous materials, let alone device systems involving
several different materials, such as in complete medical device packages. The rapidly changing mar-
ket place, technological developments, and regulations that govern them demand that the manufac-
turer be responsive, which places a priority on the ability of the manufacturer to develop products
meeting all of the regulatory burdens in a timely and expeditious manner. Establishing shelf-life
claims can be a significant bottleneck in the product development timeline. Real-time aging proto-
cols would significantly hamper the product development cycle as well as marketability and are
impracticable in today’s fast-paced environment.
The adoption of the European Medical Device Directive (MDD) in June 1998 and the mandatory
implementation of the CE label on all sterile medical devices marketed in the European Community
have resulted in the compulsory use of expiration dates on all medical device packages. In order to
obtain the CE label, all the “Essential Requirements” of the directive must be met. The MDD states
that the label must bear . . . where appropriate, an indication of the date by which the device should
be used, in safety, expressed as the year and month.