Membranes used for fluid applications in a healthcare setting may be required to reduce the risk of bacterial contamination or to retain larger particulates formed by the various drug combinations used in patient therapies. Various performance characteristics of the selected membrane will determine the efficacy of your final device. Pall offers access to materials offering high flow rates, absolute pore size ratings, biocompatibility, non-shedding, low extractables and low or high binding characteristics.


Our liquid filtration membranes have been used for decades by leading manufacturers to ensure the safe and effective administration of intravenous drug preparations. When used for in-line intravenous filtration, our materials help reduce the risk of contamination and the potential for costly secondary infections that may occur during infusion therapy. Sterilizing grade membranes are critical to ensure that infection is not transmitted through fluids contaminated with bacteria.


The liquid filtration membranes exhibit performance characteristics that hold exciting potential in the growing field of cellular and molecular-based therapeutics. As the benefits of therapeutics are further explored, we will continue to research ways to use Pall membranes to capture, collect, separate and prepare cells using these new technologies.



Selecting Liquid Filtration Membranes


Selecting a membrane for infusion therapy requires a general understanding of the features associated with each membrane and how they correlate to performance outputs. Such considerations include pore size, protein binding capacity, chemical compatibility, flow rates, extractables and throughputs. Use our extensive experience in manufacturing healthcare media to assist you in selecting the optimal materials for your intravenous development programs.



Flow Rates




When identifying the required flow rate, the first consideration is pore size and required liquid throughput. The pore size of the membrane selected is determined by the intended performance of the final device. The pore rating dictates the functional attributes of the membrane, including flow rate and throughput.


For instance, the use of membranes with larger pore sizes will result in faster flow rates and increased throughput in the same time than membranes with smaller pore sizes. It is important to note that membranes from different polymers and casting methods, while rated to the same pore size, can exhibit different flow rates and throughputs.


Equally concerning as pore size is the porosity of the membrane. Porosity is a measure of all of the open spaces or pores in a membrane. Flow rate is directly proportional to theporosity of the membrane. Our polyethersulfone membranes are a highly porous material that provide high flow rates and excellent filtration efficiency.



Drug Binding



Critical to the selection of membranes is ensuring that they have low, non-specific binding of the active ingredient. The use of low protein binding membranes is critical in the delivery and administration of today’s biotherapeutic drugs. Low protein binding membranes such as polyethersulfone (PES) help reduce the risk of potential drug interactions, as well as protect the integrity and consistency of the therapeutic dose. Inherently hydrophilic membranes also eliminate the need for wetting agents that can potentially interfere with drug analysis and biological processes.


Offered in a wide range of pore sizes, these membranes enable specific selection for IV applications protecting patients from bacteria in solutions or aggregate globule formation in lipid solutions. A specific example is our 0.2 µm polyethersulfone membrane, it is especially formulated for critical fluid applications while yielding minimal protein absorption and superior bacterial retention. The hydrophilic nature of the material allows for multiple reprimings.


Bacterial Retention/Sterility



A common risk during long-term IV therapy is contamination of IV solutions with bacteria or fungi. Hydrophilic membranes allow the passage of aqueous solutions and are used extensively in the sterilization process during drug production. These membranes are incorporated into medical devices for sterilizing preparations prior to injections and into in-line filtration devices for ensuring the sterility of any intravenous drug administration. Choose from our polyethersulfone membrane grades or materials based on the application’s chemical compatibility requirements. 







A membrane may also be chemically treated to alter its wetting characteristics by impregnating a chemical into the membrane structure, polymerization of a secondary chemistry throughout its structure or chemical modification of the base polymer after the membrane is cast. Although wetting agents may offer advantages in filtration rate, one must consider the possibility of extractables. Extractables are substances that may leach or otherwise come off the membrane or filtration system which may end up in the fluid being infused into a patient. Our inherently hydrophilic polyethersulfone membrane results have been shown to have extremely low levels of extractables reducing the concern over contamination from a secondary source.






Material Compatibility



As new drugs continue to be developed, varying material combinations increase the opportunity for incompatibility. Many different factors can influence the compatibility and stability of drugs including preservatives, buffering systems, temperature and concentration. Chemical reactions, which may include oxidation, reduction, decomposition and complex formation, can also influence material compatibilities. Physicochemical interactions can also occur, ranging from absorption, consistency, precipitation, as well as separation of dispersal systems. Pall has an extensive library of material compatibility data on our portfolio of hydrophilic membranes for infusion therapy.



PES (Polyethersulfone) – Hydrophilic

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ACP (Acrylic Copolymer) - Hydrophilic

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Nylon – Hydrophilic

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