Skip to Content
MilliporeSigma
HomeBioburden and Aseptic Control StrategyAseptic Filter Formats: Selection Guide

Aseptic Filter Formats: Selection Guide

White and blue filters capsule filters of different formats and sizes. Blue filters are gamma compatible, white capsules are autoclave-compatible and both contain Millipore Express® membrane.  Cartridge filter elements with no filter housing are shown .

Aseptic capsule and cartridge filters.

Aseptic membrane filters are a key components of bioprocessing bioburden control strategies, both in upstream and downstream processing. To meet the diverse needs of drug manufacturing from process development through to large-scale manufacturing, our aseptic membrane filters are offered in disposable capsules for single-use processing and cartridge formats for stainless-steel operations. This technical article provides a high level overview of different formats available to help guide product selection. For specific information on any filter, please check the product specifications.

Important Considerations for Any Drug Manufacturer

  • Quality:  Our aseptic filters are designed, developed, and manufactured in accordance with a quality management system approved by an accredited registering body to an ISO 9001 quality systems standard. All filters are subject to multiple quality control release tests and are supported by a Certificate of Quality.
  • Compliance and Control: Many of our aseptic filters are supported by the Emprove® Program which offers access to product and testing information to help you stay ahead of constantly evolving regulatory requirements. This information supports different steps in your raw material and component risk assessment continuum – streamlining your supplier selection, material qualification, process optimization and patient safety evaluation.

Small Scale Tools for Reliable Screening and Scaling

OptiScale® capsules are small-scale ‘drop-in’, single-use filters typically used for process development and for estimating filtration area requirements in larger scale processes. The small filtration area and low hold up volume means your limited volume of process fluid goes further.

OptiScale® capsules are offered in two sizes: OptiScale® 25 (3.5 cm2) and OptiScale® 47 (17.7 cm2) capsules. While both sizes can be used for screening filter performance, OptiScale® 25 filters are preferred for estimating filtration area requirements for scale-up as the component membrane performance is selected to be more representative of large scale devices. Studies to estimate filtration area requirements are commonly performed using the Vmax™ constant pressure test

For help with screening studies or sizing aseptic filters.

On left white small scale capsule with ‘Millipore Express®’ on label. On right, white and blue capsule with “Millipore” and “OptiScale” written on the side.

OptiScale® 25 capsule and OptiScale® 47 capsule.

Cartridge Filters for Stainless-Steel Processes

Cartridge filters are typically used in more traditional, multi-use, stainless-steel operations that require larger filtration areas or lower operating costs. These filter elements are used with filter housings and provide high flow rates and throughput with minimal differential pressure.

Cartridge filters are offered with all filtration membranes and, dependent on membrane, may be offered in different sizes.  All cartridge filters are available with multiple connections options for different processing needs and are designed to withstand multiple steam in place cycles, assuring robust reliable performance.

Cartoon showing parts of a cartridge filter. At bottom there is an adaptor with O-rings and at top there is a spear to direct positioning in housing. The pleated retentive membrane is sandwiched between upstream and downstream support layers around a core, inside a protective sleeve with endcaps at top and bottom.

Cartoon image showing the component parts of an aseptic pleated cartridge filter.

Opticap® Capsules for Pilot and Production Scale Processing

Opticap® disposable capsules offer increased flexibility, more rapid turnaround, and less manufacturing downtime and minimize the cleaning, assembly and validation associated with stainless steel operations. All Opticap® capsules contain pleated filter elements inside the capsule housing.

Opticap® XL and Small Scale 300 capsules are ideal for smaller processes or pilot scale manufacturing. Opticap® XLT and Opticap® T-line capsules are designed for larger volume production and have a T-line design that accommodates series or parallel filtration.  These capsules are available with or without a gauge port for ease in monitoring process conditions.

All Opticap® capsules are offered with different connection options for easy integration into different process configurations.

  • Opticap® XL  and Opticap® XLT capsules are available with multiple membranes
  • Opticap® T-line and Small Scale 300 capsules are only available with Milligard® PES membranes 
  • Opticap® XL 150, Opticap® XL 300 and Opticap® XL 600 are only available with Millipore Express® membranes

Dependent on the membrane, capsules are compatible with irradiation or autoclave sterilization and for some membranes presterilized capsules are available.  For maximum flexibility, irradiation-compatible capsules can be integrated into Mobius® single-use assemblies, for a ready-to-use single-use system.

High-Area Filters for More Plugging Fluid Streams

Membrane filters designed for efficient filtration of plugging fluids, such as Millipore Express® SHC and Millipore Express® SHR with Prefilter filters, are offered in high-area capsule and cartridge formats. These high-area filters feature a novel pleat pattern that increases the membrane area in the filter element, resulting in higher filter capacity without increasing filter footprint.  

For more information on sizing high area filters:

Two images of cross sections of pleated filter elements: on left, filter element with wide center core surrounded by membrane with standard  pleat pattern. On right see high area filter element with narrow core and taller membrane pleats in M pleat pattern which increases membrane area in the filter element.

Membrane pleat patterns of Standard (A) and high area (B) filters. High area filters have taller pleats (C) and narrower core (D) than standard area filters with shorter pleats (F) and wider core (E).

Specialized Filters for Critical Final Sterile Filtration Operations

3 discs to which membrane is bonded directly with no support layer

Membrane bonded directly to support discs minimizes device hold-up volume in flat disc filters

Our stacked disc filters are optimized for critical sterile filtration steps with small volume, high value products and include Millipak® capsules and Millidisk® cartridge filters. These specialized filters contain Durapore® membrane bonded to solid discs, stacked inside the filter housing. This membrane arrangement minimizes hold-up volume, resulting in higher product recoveries. 

Filter port called an AMPP, made of clear polymer which contains 3 O-rings. When the port is open the O-rings create an aseptic area between the environment and flow path.

Aseptic multi-purpose port (AMPP) on Millipak® Final Fill Filter.

Millipak® Final Fill filters are capsule filters, designed for final filtration steps, where the traditional filter vent has been replaced by an aseptic multi-purpose port (AMPP).  When the AMPP is closed, the lower O-ring seals the flow-path from the environment while the upper two O-rings maintain an aseptic area that prevents contamination entering the flow-path. The AMPP can be used for filter integrity testing, venting, and sampling and should provide confidence to the end user as flow-path integrity has been confirmed, up to 18 actuations.

 Read our Tech Note to learn more about how the AMPP prevents flowpath contamination.

For help selecting a filtration device or format:

Sign In To Continue

To continue reading please sign in or create an account.

Don't Have An Account?