Millipak
The Millipak are 0.22 µm membrane filters designed as
a safe and efficient barrier against particulates and bacteria.
The
Millipak devices use the unique, clean stacked disc design that eliminates the
risks of particulate-producing woven downstream support found in many pleated
membrane capsules.
The Millipak stacked disc concept offers several
benefits
- Adequate support of the flat
0.22 µm membrane, which is supported by a rigid plastic disc with channels to
ensure at the same time a high water flow and a resistance to pressure
variations without risk of membrane rupture.
- Membrane heat sealing on
the support that eliminates risks of contamination that may occur when the
membrane is bound by solvent.
- High surface in a small volume, with a minimum “dead volume”.
The Millipak filters were originally designed for
sterilizing filtration of pharmaceutical products and culture media.
The 0.22 µm filtration membranes used in the Millipak have been validated for
bacteria removal following the HIMA rules, using a challenge with Pseudomonas
Diminuta at 107 organisms / cm² of membrane. The bacteria retention efficiency
has been correlated during validation studies with the non destructive bubble
point and air diffusion tests in order to allow the verification of bacteria
retention for each device at the end of the manufacturing process.
Millipak Operation
These filters are used in laboratory water systems
since many years to remove particulates and also prevent the intrusion of
bacteria from the laboratory air inside the water system.
The
filling bell provides protection against airborne bacteria contamination when
ultrapure water is delivered; the filling bell and cap limit airborne bacteria
intrusion in the water downstream of the 0.22 µm membrane when the system is
not used.
Whenever it is important to reduce bacteria contamination
of the ultrapure water, it is a good laboratory practice to keep the filling
bell with the end cap in place when the system is not used, and to throw away
at least 100 mL of water every morning to eliminate the airborne bacteria that
might have developed during the night in the water volume downstream of the
membrane. The connection of tubing at the outlet of the Millipak should be
avoided as numerous experimentations have demonstrated that such tubing leads
inevitably to bacteria development and water contamination.
Millipak High Quality End Filters
Millipak end filters have been designed not only for
efficient particulate and bacteria retention; they are also tested to ensure
that they will not contaminate the processed liquid by extractible or other
contaminants.
This is reflected in the Certificate of Quality
delivered with every Millipak where the following Quality Assurance parameters
are reported
- Good Manufacturing
Practices
- ISO® 9001 Quality Standard
- Non Fiber releasing
- Components Materials Toxicity test
- Membrane Bacterial Retention
- 100% Integrity testing in Manufacturing
- USP Bacterial
Endotoxin test Integrity test
- Hydraulic Stress Test
- Flow Rate
and Pressure Drop Measure
- USP Oxidizable Substances test
- Gravimetric Extractible test
- Sterility test (for products delivered sterile)

