2. 2
“Application of filtration process in pharmaceutical
Industry”
Filtration
Solids and liquids are separated during filtration operations. Filters have different designs
and features with varying containment and control of liquids and vapours . When open
filters are used for hazardous materials, workers may be exposed to liquids, wet solids,
vapours and aerosols during loading and unloading operations. Closed process equipment
can be used to filter highly hazardous materials, reducing vapour emissions and preventing
worker exposures. Filtration should be performed in areas with spill control and good
dilution and LEV. Volatile solvent vapours can be exhausted through vents on sealed
process equipment and controlled by air emissions devices (e.g., condensers, scrubbers and
adsorbers).
Figure . A sparkler filter
3. 3
Air Filtration
1. Membrane
A compressed gas should be of appropriate purity (e.g., free from oil) and its
microbiological and particle quality after filtration should be equal to or better than that of
the air in the environment into which the gas is introduced. Compressed gases such as air,
nitrogen, and carbon dioxide are often used in cleanrooms and are frequently employed in
purging or overlaying.
Membrane filters can be used to filter a compressed gas to meet an appropriate high-
quality standard. These filters are often used to produce a sterile compressed gas to
conduct operations involving sterile materials, such as components and equipment. For
example, we recommend that sterile membrane filters be used for autoclave air lines,
lyophilizer vacuum breaks, and tanks containing sterilized materials. Sterilized holding
tanks and any contained liquids should be held under positive pressure or appropriately
sealed to prevent microbial contamination. Safeguards should be in place to prevent a
pressure change that can result in contamination due to back flow of nonsterile air or
liquid.
Gas filters (including vent filters) should be dry. Condensate on a gas filter can cause
blockage during use or allow for the growth of microorganisms. Use of hydrophobic filters,
as well as application of heat to these filters where appropriate, prevents problematic
moisture residues. We recommend that filters that serve as sterile boundaries or supply
sterile gases that can affect product be integrity tested upon installation and periodically
thereafter (e.g., end of use). Integrity tests are also recommended after activities that may
damage the filter. Integrity test failures should be investigated, and filters should be
replaced at appropriate, defined intervals.
2. High-Efficiency Particulate Air (HEPA)
HEPA filter integrity should be maintained to ensure aseptic conditions. Leak testing
should be performed at installation to detect integrity breaches around the sealing gaskets,
through the frames, or through various points on the filter media. Thereafter, leak tests
should be performed at suitable time intervals for HEPA filters in the aseptic processing
facility. For example, such testing should be performed twice a year for the aseptic
processing room. Additional testing may be appropriate when air quality is found to be
unacceptable, facility renovations might be the cause of disturbances to ceiling or wall
structures, or as part of an investigation into a media fill or drug product sterility failure.
Among the filters that should be leak tested are those installed in dry heat depyrogenation
tunnels and ovens commonly used to depyrogenate glass vials. Where justified, alternate
methods can be used to test HEPA filters in the hot zones of these tunnels and ovens.
4. 4
Adsorptive Depth Filtration
Activated carbon is used in the pharmaceutical industry to remove impurities from active
ingredient manufacturing. These impurities are typically derived from chemical reactions
that produce colored by-products. These colored by-products must be removed to maintain
drug purity and produce high-quality, on-spec intermediate compoundsActivated carbon
use in powdered form presents three primary areas of concern to the pharmaceutical
manufacturer, namely operator exposure to carbon dust, the quality of the process and the
operating costs associated with the use and handling of bulk activated carbon.
Figure . Adsorptive Depth Filtration
5. 5
Solvent & Bulk Chemical Filtration
Chemicals and solvents used in pharmaceutical manufacturing include alcohol, acetone,
methylene chloride and numerous other bulk chemicals for raw materials. Active
pharmaceutical ingredients are synthesized through chemical reactions that use solvents
together with other ingredients including catalysts. These bulk chemicals should be free of
particulate matter and contaminants prior to their use in manufacturing processes in order
to maintain process integrity and overall product quality.
6. 6
Sterilizing Grade Filtration (liquid & gas)
Sterilizing grade filtration requires robust filters designed for performance certification to
standards established by regulatory agencies, including absolute retention of certain
microorganisms and certification of filter integrity by the manufacturer. 3M Purification
supplies a variety of filter options for use in sterilizing grade filtration applications.
The applications for these products include:
• Nitrogen filtration and tank venting
• High Purity DI water and WFI systems
• Parenterals (SVP, LVP)
• Opthalmics
• Biologicals
0
7. 7
Water filtration
The water, steam and utilities used in pharmaceutical production is typically filtered to
remove particles, scale and impurities prior to its use. 3M Purification offers a variety of
filter options to meet the needs of these utility applications.
Water filtration is perhaps the most common application in the pharmaceutical industry.
Different standards for water quality exist in the pharmaceutical industry depending on
the application.
• USP Water for Injection (WFI)—for product formulation, equipment and container
cleaning and WFI steam production.
• USP Purified Water—for equipment and container cleaning, fermenter make-up water
(sterile filtered) and clean steam production.
• Utilities water—for heating/cooling process equipment.
11. 11
References
1. Innovative Filtration Performance. Quality. Service.
2. Process Filtration Applications Pharmaceutical and Biotechnology Industries
- Donaldson
3. Guidance for Industry Sterile Drug Products Produced by Aseptic
Processing — Current Good Manufacturing Practice
4. FILTRATION SOLUTIONS
Pharmaceutical Manufacturing
-Amazon
5. Solutions for pharmaceutical filtration processes
6. Andrew L, Doug N and Derek J (2002) Mineral processing, plant
design, practice and control.
7. Subramanyam CVS, Setty TJ, Suresh S and Devi KV (2005)
Filtration In pharmaceutical engineering principles and practices,
Vallabh prakashan.
