Integrity checks of medical packaging are vital to assure sterility, shelf life and safety of use. A manufacturer of medical packaging is usually required to carry out quality assurance checks to assure integrity. However, end users or third party laboratories may also carry out such integrity checks on behalf of end user or the manufacturer and issue a certificate.
The package design and materials used as well as the seal design and structure play a role in integrity.Manufacturers must show that integrity is not affected due to aging or handling or influence of pressure and dynamic stresses during normal use during the specified lifecycle. Several methods may be adopted to assure integrity.
Package design is a crucial step. Shape, method of sealing and method of manufacture need to be meticulously implemented for a package to retain integrity. However, how it performs in real life also provides feedback to modifications in order to achieve improvements. Design goes hand in hand with prototyping, tests, refining and further tests to arrive at a final workable design.
The characteristics of the packaging for specific end uses are defined and characterized. The tests cover leaks, positive and negative pressure tests, vacuum test, gravimetric and tracer gas tests. Tests may be carried out in environmental test chambers where temperature, humidity and vacuum are controlled. Packaging may be subjected to physical rough handling to simulate conditions during storage and transport.
Performance integrity is checked using a series of tests for leak rate, vapour transmission accelerated aging test, pressure and vacuum maintenance, resistance to physical deformation and damage, simulation of distribution conditions, humidity, temperature and pressure tests. Each parameter is precisely measurred and documented. ASTM-F1886 defines standard test method for checking integrity of seals by visual inspection. These rely on degree of contrast between sealed and unsealed areas, light reflection angle, magnification, check of adhesive between lamination and others.
However, much before these integrity checks are carried out, it is important to consider other aspects. These cover:
- Identification of regulations for sterility maintenance, barrier protection, shelf life verification, distribution and temperature control from manufacturer’s end to transit to end user storage.
- It is equally important to define the packaging inputs and the processing capabilities. Design of package and method as well as materials need to be chosen to align with production capability.
- The way products are stored and distribute also affect integrity of packaging. A product may move from a cold climate to a hot humid tropical environment. It may be shipped by air at high altitudes where the storage compartment may experience near zero conditions or it may travel the sea route with its high amount of salt and moisture laden atmosphere.
- Risk assessment is another factor to be considered prior to designing and production of a product that will stand up to any integrity check.
All these factors must be taken into consideration before a packaging is desiged that will withstand the strictest integrity checks.