Packaging for Medical Devices
Medical device is best defined as the product items or component thereof
which does not achieve any of its principal intended purposes through
chemical action within or on the body of human or animals and not dependant
on being metabolized for obtaining the intended objective. Thus the words
chemical action and metabolized essentially miss between a drug and medical
device. The medical devices are classified under three regulatory classes
based on the significance and in assuring their safety. Theses fall under
those regulatory classes:
- General Controls
- Special Controls
- Pre-Market Approval
In medical device packaging several functions are being inbuilt and to that
extent packaging becomes an integral part of the development of the product
or system. Besides being a container, a carrier for transport, protection
and identification packaging in this instance also implies a sterile barrier
in terms of protection from microorganism and other physical contamination.
The packaging medium should possess inherent characteristics such as maximum
pore size and pinhole freeness. The other significant feature expected is
the package integrity ensuring no breaks or seal failure leak or openings
that will affect product quality. Even atmospheric or environmental factors
that would come into play should be considered in the material selection.
This will include heat, light, stresses etc. What is thus expected is the
total ability to keep the product safe and secure.
The package also is the information and identification source as a vehicle
to carry messages related to product use, safety, storage, product identity,
precautions etc. The print details should be legible, accurate and clear,
misprint or misregistration should be avoided.
In medical device packaging the primary importance attached to is
maintenance of sterility all through the distribution and till it is put to
use. Peelable packaging which probably constitutes a major percentage of
medical device packaging is typical of above needs. The medical device
packaging also can have in-built added features such as measuring device,
dispensing mechanism, stabilizing stand, disposal receptacle etc. This
clearly emphasizes the multidimensional and multifunctional features through
Various forms of packages are in use for medical devices. The form is often
decided by the product characteristics, the physical features and dosage
aspects. The commonly used types include thermoformed trays, flexible webs,
flexible non formed pouches, bags and vented flexible bags, laminated and
co-extruded structures formed though FFS systems, cartons and wraps. The use
of glass and metals are very limited. Commercial availability of
thermoformable plastics, high tech laminated and barrier structures and
functionally sound and easily peelable lidding materials have helped a boon
to medical device packaging. Nonwoven synthetic has revolutionsed
disposables' packaging. Flexible webs as top or base layer have also added
to sterilizable and easy openable packs. Flexible pouches are more common
for single dose disposable items.
While physical and dimensional stability, product package compatibility,
shelf life, physical protection, and environmental preservation are of
significant features to be identified with the package for medical devices,
sterility, and sterilization get uppermost needs of the packaging system.
The common methods of sterilization include ethylene oxide (ETO), radiation
(gamma) sterilization, steam or autoclave, dry heat and plasma
sterilization. The method of sterilization can have an effect on the
packaging material used and possible package interaction. Hence selection of
the packaging media is to be governed by the sterilization method to be
Factors like temperature, pre humidification, evacuation and gassing rate,
cycle time, gas mix, quality of seal and chemical compatibility can affect
seal integrity in the ETO sterilization. The key criteria of the packaging
material will thus be porosity, compatibility, hot tack and moisture.
Material degradation is the significant aspect to be considered in the gamma
ray irradiation. Autoclave/ steam sterilization identified problems such as
inconsistent peelability, poor control on seal film splitting, dimensional
stability, distortion etc. Where steam sterilization is desired / selected
the material characteristics to be looked into are porosity, high barrier
for retort sterilization, resistance to microorganism, product
compatibility, effective seal and yet easy openability, and economics.
Materials used for dry heat sterilization should be able to withstand long
hours of controlled elevated temperatures. Plasma sterilization has been on
the increase since the recent years. Post/sterilization of prepacked OEM,
medical devices are potential products for plasma sterilization besides in
hospitals. Due to low toxicity of sterilization by products this technique
is finding wide spread applications.