Method of final filling assembly and integrity testing

Abstract

Apparatus and methods are disclosed for redundant filtration assemblies including filters with multi-purpose vent ports, which reduce the part count and overall size of the assembly and help minimize product loss. Method(s) for performing pre-use post-sterilization integrity testing (PUPSIT) are also disclosed.

Description

Technical Field

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 115,838, filed on November 19, 2020, the entire contents of which are incorporated herein by reference in their entirety.

[0002] Embodiments of the present disclosure relate to the treatment of biological fluids. More specifically, the embodiments disclosed herein relate to integrity testing of devices used in bioprocesses.

Background Art

[0003] As manufacturers strive to meet production schedule requirements, disposable assemblies are increasingly being implemented throughout the manufacture of biological products to minimize cleaning, improve efficiency, and maximize flexibility. Sterilized disposable assemblies offer advantages for the final filtration and filling operations, which are important for maintaining sterility to ensure biopharmaceutical and drug safety for patients. Due to the high cost of the final filtration of biological products, past traditional prior art assemblies involved the use of redundant filters in addition to primary filters to ensure that the final filtration was performed correctly. Disposable redundant filtration assemblies are referred to as SURF assemblies.

[0004] As the manufacturing process has evolved, the design of the filter capsule has also evolved. For example, past capsule filters included traditional filter outlets, which have been replaced by special ports that have been verified to prevent microorganisms from the external environment from entering the sterile flow path. This special port can be used for ventilation, sampling, and connection of air lines, thus simplifying the pre-sterilization integrity test (PUPSIT) after use. In contrast to conventional filter outlets, the sterile multi-purpose port (or known as "AMPP") is designed to maintain a sterile connection while withstanding the high pressure required for the filter integrity test. In addition, pressure can be applied through the sterile multi-purpose port following the process of recovering the product within the filtration system. In small-scale processes or when highly expensive drugs are being processed, this recovery step can have significant economic benefits.

[0005] Overall, the design of the SURF assembly aims to minimize product loss occurring during the filtration operation and the ability to recover the product within the assembly. This can be achieved by reducing the total hold-up volume of the SURF assembly or by introducing multiple recovery steps after filtration. Such recovery steps must not compromise the sterility of the assembly. However, past SURF assemblies have required the use of redundant final filling filters and barrier filters. Multiple past SURF assemblies may include two separate filters instead of one barrier filter, where one filter functions as the gas outlet and one as the liquid outlet. Summary of the Invention Problems to be Solved by the Invention

[0006] An efficiency-enhanced redundant filtration assembly with reduced hold-up volume and minimizing product loss during filtration operations, having fewer barrier filters and / or gas filters and / or liquid filters, would represent an advancement in the art. A post-sterilization integrity test with fewer barrier filters and / or gas filters and / or liquid filters would also represent an advancement in the art.

Means for Solving the Problem

[0007] One embodiment described herein includes an efficiency-enhanced redundant filtration assembly comprising a main conduit for delivering a biological product, the main conduit including a primary final fill filter provided within the main conduit, a first connector and a second connector at the terminal end of the main conduit, a clamp provided within the main conduit downstream of the first connector, a redundant final fill filter provided within the main conduit, an air line in fluid communication with the redundant final fill filter, the air line being joined to the main conduit and further comprising an integrity test connection at its distal end, an outlet connected to the air line, at least one vent bag in fluid communication with the redundant final fill filter, two clamps provided downstream of the redundant final fill filter, the two clamps having a pinch clamp provided therebetween, wherein the two vent bags, the air line, and optional clamps and gas filters are in fluid communication with the primary filter, the clamp is provided within the main conduit downstream of the primary filter, a secondary conduit is joined to the main conduit, the secondary conduit further comprises a barrier filter, the barrier filter and the secondary conduit merge with the main conduit, the pinch clamp is provided within the main conduit, and the main conduit terminates at the second connector.

[0008] In some embodiments, the redundant filtration assembly comprises an integrity test connection connected to an air supply source. In some embodiments, the redundant filtration assembly comprises a gas filter downstream of the integrity test connection. In some embodiments, the redundant filtration assembly comprises two vent bags. In some embodiments, the redundant filtration assembly further comprises a sampling bag. In some embodiments, the redundant filtration assembly further comprises a clamp or valve provided on the air line between the two vent bags. In some embodiments, the outlet is an aseptic multi-purpose port (AMPP). In some embodiments, the redundant filtration assembly further comprises a peristaltic pump having a conduit connected to the integrity test connection at a first end of the conduit. In some embodiments, the redundant filtration assembly further comprises two or more integrity test connections. In some embodiments, the redundant filtration assembly comprises a second end of a conduit connected to an integrity test connection different from the first end of the conduit. In some embodiments, the redundant filtration assembly further comprises a recirculation container. In some embodiments, the redundant filtration assembly further comprises a data acquisition system. In some embodiments, the redundant filtration assembly is disposable. In some embodiments, the redundant filtration assembly comprises stainless steel. In some embodiments, the redundant filtration assembly comprises stainless steel and disposable components.

[0009] One embodiment described herein includes a method for integrity testing of at least one final fill filter of a redundant filtration assembly, the method comprising flowing a wetting liquid through the final fill filter, introducing pressurized air into the optimized redundant filtration assembly through an air line further comprising an integrity test connection at the distal end, draining the wetting liquid from the assembly, passing the pressurized air through a gas filter at the air inlet, through the outlet and through the final fill filter before exiting the optimized redundant filtration assembly through the outlet, and performing at least one test selected from the group consisting of a bubble point test, a diffusion test, a water flow test, and a pressure hold test. In the method according to claim 16, the outlet is a sterile multi-purpose port (AMPP) vent port. The method according to any one of claims 16 and 17 further comprises arranging a clamp between the primary filter and the redundant filter, thereby avoiding fluid communication between the downstream side of the redundant filter and the air inlet of the primary filter.

[0010] In certain embodiments of the method, the draining step is performed using gravity drainage. In certain embodiments of the method, the draining step is performed using blowdown. In certain embodiments of the method, the final fill filter is a primary final fill filter. In certain embodiments of the method, the final fill filter is a redundant final fill filter. In certain embodiments, the method further comprises the step of closing the AMPP vent port of the primary filter. In certain embodiments of the method, the barrier filter is the final outlet of pressurized air. In certain embodiments, the method further comprises the step of opening the AMPP vent port of the primary filter. In certain embodiments of the method, the AMPP vent port is the final outlet of pressurized air. In certain embodiments of the method, the pressurized air sequentially passes through the air supply port for the redundant final fill filter and the redundant final fill filter, and exits the redundant filtration assembly through the AMPP vent port of the redundant final fill filter. In certain embodiments of the method, the pressurized air sequentially passes through the air supply port of the redundant final fill filter into the redundant final fill filter, and exits the redundant filtration assembly through the AMPP vent port of the primary final fill filter. In certain embodiments of the method, the pressurized air sequentially passes through the air supply port of the redundant final fill filter into the redundant final fill filter, and exits the redundant filtration assembly through the air supply port of the primary final fill filter.

[0011] As fully set forth in the claims, an apparatus and method for a redundant filtration assembly that houses a filter having an aseptic multi-purpose vent port (AMPP), substantially as illustrated in and / or described in connection with at least one of the figures, are described herein. The redundant filtration assembly described herein reduces the number of components and the overall size of the assembly, thereby facilitating minimization of product loss. A method (or methods) for performing a pre-use post-sterilization integrity test (PUPSIT) is also developed. The various advantages, aspects, novel and inventive features, and exemplary embodiments of the present disclosure will be more fully understood from the following description and drawings.

Brief Description of the Drawings

[0012]

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[0013] The features disclosed herein can be understood in a way that allows for a more detailed understanding, and a more specific description of the embodiments of the present disclosure, briefly summarized above, can be obtained by referring to the accompanying drawings. However, it should be noted that the accompanying drawings show only certain embodiments of the present disclosure, and thus the described and illustrated embodiments should not be considered as limiting its scope, as they may allow for other equally valid embodiments. It should also be understood that elements and features of one embodiment may be found in other embodiments without further recitation, and that the same reference numbers may be used to indicate similar elements common to the figures.

[0014] Definitions As used herein, the term "barrier filter" has both hydrophobic and hydrophilic components and can thus be used in place of two filters, where one is hydrophilic and the other is hydrophobic for gases.

[0015] As used herein, the term "depth filter" is a filter that achieves filtration within the depth of the filter material. Particle separation in a depth filter results from capture or adsorption by fibers comprising the filter material and a filter aid matrix.

[0016] As used herein, the terms "sterile" and "sterilized" are defined as free of contaminants, particularly in the bioprocessing industry, as being free of undesirable viruses, bacteria, pathogens, and other microorganisms such as pathogens. In this context, the terms "bioburden reduced" and "bioburden reduction" (e.g., by non-sterilizing irradiation with gamma or X-ray radiation of less than 25 kGy) may be replaced in certain embodiments that do not require sterilization claims.

[0017] As used herein, the term "upstream" is defined as the first stage process of a treatment in which biological materials such as microorganisms / cells, mAbs, ADCs, proteins including therapeutic proteins, viral vectors, etc. are grown or planted in a bioreactor in a cell culture medium under controlled conditions for manufacturing a specific type of biological product.

[0018] As used herein, the term "downstream" refers to the process in which a biological product is harvested, tested, purified, concentrated, and packaged following growth and proliferation in a bioreactor.

[0019] As used herein, the term "clarification" is defined as a downstream process in which whole cells, cell debris, soluble impurities (HCP and / or DNA), suspended particles, and / or turbidity are reduced and / or removed from a cell culture feed stream using centrifugation and / or depth filtration. The terms "clarify", "clarification", "clarification step", and "harvest" generally refer to one or more steps first used in the purification of biomolecules. The clarification step generally comprises the removal of whole cells and / or cell debris during the harvest operation from the bioreactor, but may also comprise turbidity reduction of a downstream process intermediate or a pre-filter to protect other delicate filtration steps, such as virus filtration.

[0020] As used herein, the term "purification" is defined as a downstream process in which bulk contaminants and impurities, including host cell proteins, DNA, and process residues, are removed from the product stream.

[0021] As used herein, the term "polishing" is defined as a downstream process in which trace contaminants or impurities that are similar to the product in physical and chemical properties are removed from the purified product stream.

[0022] As used herein, the terms "impurity" or "contaminant" refer to any foreign or unwanted molecule, which includes DNA, RNA, one or more host cell proteins, endotoxins, lipids, aggregating polymers, surfactants, biopolymers such as (one or more) antifoam additives, and one or more additives that may be present in a sample containing a target molecule that has been separated from one or more of the foreign or unwanted molecules using the processes described herein. Additionally, such impurities may include any reagent used in steps that may be performed prior to the methods of the present invention. Impurities may be soluble or insoluble.

[0023] As used herein, the term "hold-up volume" refers to the volume of the mobile phase within the redundant filtration assembly in use.

[0024] Assembly Referring to the figures, FIG. 1 shows a typical prior art redundant filtration assembly using a redundant filter and a primary filter, where the filter may be a Millipak(R) Final Fill filter or any other sterilizing filter. In most other sterilizing filters, the air line for integrity testing cannot be directly connected to the outlet of the filter. Therefore, as shown in FIG. 1, an additional inlet for integrity testing is required. In addition, prior to the integrity test, the filter must be wetted using a wetting fluid at a specific pressure and flow rate. Typically, the wetting fluid must pass through each filter and exit the assembly using another connection. This connection can include any sterilizing filter or sterilized bag, or a hydrophilic / hydrophobic filter (shown in FIG. 1). Similarly, the pressurized air used for the integrity test must also pass through each filter and exit the assembly using a connection. This connection can include a gas filter or a hydrophilic / hydrophobic filter (shown in FIG. 1). In summary, the connections for liquids and gases to exit the assembly after passing through each filter may include hydrophilic / hydrophobic filters or separate gas and liquid filters. In the exemplary figure shown in FIG. 1, during the wetting process, the wetting fluid exits the assembly through the Millipak(R) Barrier filter downstream of each Final Fill filter, whereby the Millipak(R) Barrier filter is a hydrophobic / hydrophilic filter.

[0025] In addition to the barrier filter, the assembly may include a plurality of vent bags to ensure proper ventilation of the assembly during the wetting process or prior to the filtration step. These vent bags are sterilized and are connected to the vent ports of the final fill filter. To ensure that the pressurized air introduced into the redundant filtration assembly is sterile and does not compromise the sterility of the assembly during operation, there may be an additional hydrophobic gas filter on the air line for integrity testing. To track the pressure during different steps of the final filling operation, there may be an additional pressure sensor upstream of each of the final fill filters.

[0026] Figure 2 shows the flow direction of pressurized air when moving outward from each barrier filter through the final filter of a traditional final fill assembly in a prior art method for integrity testing. Each of the final fill filters has an inlet connection connected to a source of air. The barrier filter can be replaced with any suitable gas filter. The pre-use integrity testing of the two filters on the assembly as part of the PUPSIT operation is generally performed one at a time. For example, the primary filter is first integrity tested with the redundant filter of the assembly clamped off. For example, this clamp can be placed between the connection for the barrier filter downstream of the redundant final fill filter and the connection for the air supply port for integrity testing of the primary filter. After the integrity test is completed, this clamp can be removed for the final filtration operation. Flow directions F1, F2, F3, F4, and F5 are shown.

[0027] Efficient Redundant Filtration Final Fill Assembly Design Certain embodiments of the present disclosure also describe an efficiency-enhanced redundant filtration assembly that minimizes the hold-up volume for a product, thereby minimizing potential product loss, and a method for integrity testing the filters of the assembly. Certain embodiments of the assembly include two or more filters, i.e., are redundant. Thus, certain embodiments of the redundant filtration assembly comprise at least two final fill filters. As shown by the efficiency-enhanced redundant filtration assembly in the figure, there may be fewer barrier filters.

[0028] Figure 3 shows an embodiment of an efficiency-enhanced redundant filtration assembly that reduces the hold-up volume and minimizes product loss during the filtration operation. The assembly shown in Figure 3 consists of fewer total components compared to the assembly shown in Figure 1. Figure 3 shows the efficiency-enhanced redundant filtration assembly 100. The efficiency-enhanced redundant filtration assembly 100 includes a main conduit 44 through which a product, i.e., a biological product, flows. The main conduit 44 includes a first connector 48 and a second connector 48 at the terminal end of the main conduit 44. A pinch clamp 20 is provided within the main conduit 44 downstream of the first connector 48. A redundant final fill filter 30, such as a Millipak(R) Final Fill filter commercially available from EMD Millipore Corporation of Billerica, Massachusetts, USA, is provided within the main conduit 44. An air line 62 is in fluid communication with the redundant final fill filter 30. The air line 62 includes an integrity test connector 10 at its distal end, which may be connected to an air supply source for an integrity test. A gas filter 12 is optionally provided downstream of the integrity test connector 10. After the integrity test connector 10, two vent bags 16 are in fluid communication with the redundant final fill filter 30. A clamp or valve 14 is optionally provided in the air line 62 between the vent bags 16. Two clamps 46, such as tri-clamps for connecting sanitary fittings, are provided downstream of the redundant final fill filter 30, and the pinch clamp is provided between the two clamps 46. A primary filter 30, such as the final fill filter 30, is provided within the main conduit 44. The two vent bags 16, or the vent bags 16 and the sampling bag 19, the air line 62, and the optional clamp 14 and gas filter 12 are in fluid communication with the primary filter 30 as described above. The clamp 46 is provided within the main conduit 44 downstream of the primary filter 30. A secondary conduit 34 merges with the main conduit 44. The secondary conduit 34 includes a barrier filter 40, such as a Millipak(R) Barrier filter. After the barrier filter 40, the secondary conduit 34 merges with the main conduit 44. Thereafter, a pinch clamp is provided on the main conduit 44, which terminates at the second connector 48.In certain embodiments, the tri-clamp 46 and each sanitary fitting may be replaced using a hose barb fitting in combination with a suitable hose clamp.

[0029] First, the air line required to perform the integrity test is connected to an outlet called an aseptic multi-purpose port (AMPP) instead of a dedicated connection for the air line. This reduces the need for multiple pipes and connections. Additionally, the barrier filter downstream of the redundant filter has been removed compared to the assembly of FIG. 1. In other embodiments, a combination of a gas and a liquid filter used in place of the barrier filter may also be removed to streamline a redundant filtration assembly that requires a combination of a gas and a liquid filter instead of the barrier filter immediately downstream of the primary final fill filter. As a result of these changes, the redundant filtration assembly shown in FIG. 3 is smaller and includes fewer connections compared to the redundant filtration assembly shown in FIG. 1. Fewer connections result in a reduced risk of loss of sterility through the connections.

[0030] The two assemblies shown in FIGS. 1 and 3 were compared by performing a recovery analysis. To simulate different formulations, each assembly was tested using three solutions of different viscosities, namely water and 15% and 18% polyethylene glycol (PEG) 20000 solutions having viscosities of approximately 25 and 50 centipoise (cP), respectively. For water and the high-viscosity solutions, the volume was corrected for solution density. Investigations were conducted using the main flow path at both horizontal and 45-degree angles. Additionally, the non-recoverable product from the streamlined redundant filtration assembly shown in FIG. 3 was also determined using flow paths at 65-degree and 90-degree angles. The recovery analysis was compared for different recovery methods. The recovery methods include no recovery, gravity drainage, and blowdown at different pressures.

[0031] Figure 4 shows an experimental setup for comparing recovery or product loss using the redundant filtration assemblies shown in FIGS. 1 and 3. This setup includes a recirculation vessel and a data acquisition system for measuring the mass (and volume) of product lost after a specific recovery step. A peristaltic pump is used to circulate liquid from the circulation tank into the assembly. Prior to the test, an empty recirculation vessel and a vessel filled with the test fluid were weighed. The assembly was wetted with a test fluid to simulate standard processing conditions in order to measure the volume of liquid retained within the system. Prior to introducing the liquid, the lines to the inlet, outlet, and vent bag were opened, and the lines to the sampling bag, barrier filter, and air line were clamped shut. The fluid was pumped into the assembly using a peristaltic pump at approximately 2.7 mL / min (10 psi) for water and approximately 200 mL / min (30 psi) for the PEG solution. Air was vented from the filter and collected in the vent bag. After venting, all outlets were closed. The difference in weight of the recirculation vessel before and after assembly wetting was used to calculate the unrecovered liquid or hold-up volume of the assembly. FIG. 4A shows the experimental setup for the redundant filtration assembly 50 of FIG. 1. FIG. 4B shows the experimental setup for an embodiment of the optimized redundant filtration assembly 100 of FIG. 3. Both experimental setups of FIGS. 4A and 4B include a peristaltic pump 60 having a conduit 72 connected to the integrity test connector 48, a recirculation vessel 80, and a data acquisition system 70 such as a balance. The second end of the conduit 72 is connected to a second integrity test connector 48 after passing through the media in the fluid within the recirculation vessel 80.

[0032] As shown in FIG. 5, the optimized assembly according to embodiments of the present disclosure has a significantly smaller hold-up volume, at least in part due to its smaller size. When no recovery is contemplated, approximately 325 mL can be lost in a traditional assembly compared to approximately 270 mL or less in an optimized redundant filtration assembly. Due to the high value of the product at this step, this can represent a significant savings for the process.

[0033] After analyzing the hold-up volume, the clamps on the outlet and air line were released for both the traditional assembly and the efficiency-enhanced assembly. For the efficiency-enhanced assembly, the AMPP was also released. The assembly was drained into the recirculation container for 20 minutes. To obtain recovery using gravity drainage, the difference in volume of the recirculation container after wetting and gravity drainage was calculated.

[0034] Figure 6 shows the difference in product loss according to an embodiment of the present disclosure after gravity drainage was employed as a recovery step between the redundant filtration assembly of FIG. 1 and the efficiency-enhanced redundant filtration assembly of FIG. 3. Figure 6 shows that when gravity drainage is performed as a recovery step and water is used as the liquid, the unrecovered liquid or product loss is the same as in the case of the two redundant filtration assemblies, and the efficiency-enhanced assembly shows less product loss for viscous liquids. This improvement is due to the smaller hold-up volume of the efficiency-enhanced assembly and is a direct result of the new design.

[0035] After gravity draining the assembly, the remaining liquid held within the assembly is recovered by blowing it down with the aid of pressurized air. Since the air source is connected to the assembly at two different locations for the two assemblies, the blow-down protocol varies slightly for each case. For the traditional prior art redundant filtration assembly, a 70 PSI (pounds per square inch) blow-down was performed through the inlet of the filter. The main flow path upstream of the secondary filter was closed, and the air source to that filter was connected to the air line. The air line was opened, the secondary filter was pressurized to 70 PSI, and the drained liquid was collected. The air source was moved to the primary filter air line, the secondary filter was isolated by clamping between the two filters, and the primary filter was blown down.

[0036] In the efficiency-enhanced redundant filtration assembly, blowdown was carried out continuously at 10 PSI and then at 70 PSI through the AMPP. The pipes connecting the outlet and the sampling bag to the air line were closed with valves. The air source was connected to the secondary filter through the AMPP, and the AMPP on the primary filter was closed. The air line was opened to pressurize the secondary filter to 10 psi, and the drained liquid was collected. The air source was moved to the primary filter air line connected through the AMPP, the secondary filter was isolated by clamping between the two filters, and the primary filter was blowdown at 10 PSI. After the 10 PSI test, the procedure was repeated using 70 PSI pressurized air.

[0037] Figure 7 shows the un-recovered liquid according to the recovery method of different liquids with various viscosities to simulate the formulation. Figure 7 shows that by using blowdown, the product loss can be minimized to an amount that is almost very small compared to the hold-up volume. However, when blowdown is contemplated, this can form a gas-liquid interface with the formulation being filtered. This gas-liquid interface can cause a large amount of foaming that can be harmful to product quality. Therefore, the blowdown procedure can minimize product loss, but consideration of product quality is also important.

[0038] Figure 8 shows the effect of the assembly angle on the degree of product loss. Recovering liquid from the assembly using gravity is only possible when the main axis of the product flow path is not in the horizontal position but at an angle to a higher level of redundant filter compared to the primary filter. This modification to the assembly orientation means that at least 70% of the liquid in the assembly can be recovered using gravity without using additional recovery steps. Increasing the angle of the main flow path of the efficiency-enhanced assembly to 45 degrees to 65 degrees or 90 degrees results in a slightly higher recovery amount, which may be worth considering for high-value products. However, when the system is at 90 degrees, venting the filter becomes more difficult, as reflected by the presence of more air and less liquid in the system.

[0039] The integrity test was performed using an automated integrity tester known to those skilled in the art. At least one such integrity tester is the Integritest(R) 5 Integrity Tester commercially available from EMD Millipore Corporation. The Integritest(R) 5 Integrity Tester supports traditional tests such as diffusion, bubble point, HydroCORR(TM), and pressure hold tests. The bubble point test uses the tangent method and performs pressure decay measurements at different applied pressures to map the integrity profile of the filter.

[0040] The pass / fail of the integrity test is determined based on the measurement of the bubble point of the filter. The bubble point is defined as the pressure at which bulk gas flow is observed through the filter. A bubble point result higher than the specified bubble point is considered a passed integrity test, and a bubble point lower than the specified bubble point is defined as a failed integrity test. The automated integrity tester relies on the ideal gas flow principle (PV = nRT, where P is pressure, V = volume, n = number of molecules, R = gas constant, and T = temperature). Typically, pressure is applied to the filter and gas flow is measured. Prior to bulk gas flow, the flow through the wet filter increases linearly with increasing pressure. This is called diffusive gas flow. Beyond the pressure above the bubble point, since gas can flow through the filter pores, the flow rate increases exponentially with increasing pressure. The intersection between these two curves is called the bubble point.

[0041] The automatic integrity tester has certain limitations for the determination of bubble point. For example, the tester may indicate an "invalid" result if it takes too long or too short a time to obtain a bulk flow. For example, the Millipak(R) Final Fill filter has a specified bubble point of 50 PSI. When tested with an automatic integrity tester, the tester automatically pressurizes the filter up to 80% of the specified bubble point and starts measuring the gas flow. When this pressure stabilizes, the pressure is automatically increased by 1 - 2 PSI each time it repeats until a bulk gas flow is achieved through the filter.

[0042] As described above, a traditional prior art redundant filtration assembly can be tested for integrity as shown in Figure 2, and each of the filters on the assembly is separately integrity tested using a barrier filter (or similar gas filter) that serves as the outlet for the pressurized air used in the test.

[0043] Figures 9A and 9B show an embodiment of the flow direction of pressurized air during the integrity test of the primary final fill filter of the efficiency-enhanced redundant filtration assembly. To perform an integrity test on the filter on the efficiency-enhanced assembly such as the redundant filtration assembly 100, first, the filter is wetted by flowing a wetting liquid through both filters of the assembly. After wetting, the primary filter is integrity-tested first. For the integrity test, pressurized air is introduced into the assembly as shown by the arrows in Figure 9. Prior to the integrity test, a clamp is placed between the primary filter and the redundant filter to avoid air flow from the air inlet of the primary filter to the downstream side of the redundant filter. In addition, the assembly is gravity-drained. If the assembly is horizontal and gravity drainage is not efficient, a blowdown at a very low pressure (significantly lower than the bubble point) can be performed to drain the liquid in the assembly. Due to the position of the clamp and the availability of the barrier filter on the downstream side of the primary filter, during the integrity test, the pressurized air passes through the gas filter at the air inlet, through the primary filter via the AMPP vent port, through the barrier filter, and out of the assembly. Figure 9A shows an embodiment of the flow direction through the primary filter 30 of the efficiency-enhanced redundant filtration assembly 100. The flow of pressurized air through the final fill filter 30, the second final fill filter 30, and the barrier filter 40 is shown in Figure 9A. Figure 9B shows an embodiment of the flow direction through the redundant filter 30 of the redundant filtration efficiency-enhanced assembly 100. The flow through the final fill filter 30 and the barrier filter 40 is shown in Figure 9B.

[0044] As shown in Table 1, all tests showed that the bubble point was confirmed to be higher than the specified bubble point. Therefore, all tests showed that the integrity test was passed.

[0045]

Table 1

[0046] Integrity Test of Redundant Filters on an Efficiency-Enhanced Redundant Filtration Assembly Using a Barrier Filter as the Outlet for Pressurized Air Compared with traditional assemblies, the efficiency-enhanced redundant filtration assembly does not include a barrier filter downstream of the redundant filter. Therefore, there is no direct outlet for pressurized air. As a result, during the integrity test, a different outlet must be selected for the pressurized air. Figures 9A and 9B show the flow direction of the pressurized air during the integrity test of the redundant filter, whereby the barrier filter downstream of the filter is used as the final outlet for the air. Prior to the integrity test, the clamp placed between the primary filter and the redundant filter is removed, and the AMPP vent port of the primary filter is closed. In addition, the remainder of the assembly is gravity-drained. If the assembly is horizontal and gravity drainage is not efficient, a blowdown at a very low pressure (significantly lower than the bubble point) can be performed to drain the liquid within the assembly. As a result of this setup, the pressurized air passes through the inlet of the redundant filter and subsequently moves through the redundant filter via the AMPP vent port. The air exits the redundant filter and moves through the primary filter and the barrier filter before exiting the assembly.

[0047] Table 2 shows the results of the integrity test of the redundant filter when the flow direction of the pressurized air is as shown in Figure 9. The automated tester was unable to obtain results due to constraints. In such cases, it is valuable to understand the pressure changes upstream of both the primary filter and the redundant filter.

[0048] Figure 10 shows the pressure change as a function of time measured using pressure sensors upstream of the primary filter and the redundant filter on the redundant filtration assembly.

[0049] [Table 2]

[0050] Figure 10 shows the pressure traces upstream of both filters on the assembly. As shown, the automated tester cannot identify the bubble point of the redundant filter beyond the specified bubble point. As shown, the bubble point was not measured even at a pressure of 70 PSI upstream of the redundant filter (blue trace). This is due to the primary filter acting as another constraint on the pressurized air, and the pressure between the redundant filter and the primary filter continues to rise even beyond the expected bubble point of the redundant filter (50 PSI). This result was unexpected and indicates that, as shown in FIGS. 9A and 9B, a integrity test cannot be performed in the direction of air movement.

[0051] Integrity Testing of Redundant Filters on an Efficiency-Enhanced Assembly Using the Outlet of the Primary Filter as an Outlet Compared to traditional prior art assemblies, the efficiency-enhanced redundant filtration assembly does not include a barrier filter downstream of the redundant filter. Thus, there is no direct outlet for the pressurized air. As a result, a different outlet must be selected for the pressurized air during the integrity test. As shown in Table 2 and FIG. 10, using a barrier filter downstream of the primary filter does not lead to a successful test.

[0052] Figure 11 shows the flow direction of pressurized air during the integrity test of the redundant final fill filter of the efficiency-enhanced redundant filtration assembly. Figure 11 shows the flow direction of pressurized air during the integrity test of the redundant filter, whereby the AMPP vent port on the primary filter is used as the final air outlet. After the integrity test of the primary filter, the clamp placed between the primary filter and the redundant filter is removed. In addition, the remainder of the assembly is gravity-drained through the primary filter. If the assembly is horizontal and gravity drainage is not efficient, a blowdown at a very low pressure (significantly lower than the bubble point) can be performed to drain the liquid in the assembly. After draining all the wetting liquid from the assembly, the AMPP vent port on the primary filter is opened. As a result of this setup, pressurized air mainly passes through the inlet of the redundant filter and subsequently moves through the redundant filter via the AMPP vent port. The air exits the redundant filter and moves through the AMPP vent port on the primary filter before exiting the assembly.

[0053]

Table 3

[0054] Table 3 shows the results of the integrity test of the redundant filter when the flow direction of the pressurized air is as shown in Figure 11. The automatic tester showed the expected results with a bubble point measurement higher than the specified 50 PSI bubble point and passed the integrity test.

[0055] Figure 12 shows an embodiment of the flow direction of pressurized air during the integrity test of the redundant filter, whereby the AMPP vent port on the primary filter is used as the final air outlet. However, compared to the assembly shown in Figure 11, the assembly of Figure 12 includes additional ports and gas filters for the air to exit the assembly.

[0056] Figure 13 shows the pressure change as a function of time, measured using the pressure sensors upstream of the primary filter and the redundant filter in one embodiment of the efficiency-enhanced redundant filtration assembly. Figure 13 shows the pressure traces upstream of both filters on the assembly. Since the pressurized air can exit through the AMPP vent port of the primary filter on the assembly, the primary filter does not provide an air restriction and the integrity test is completed successfully. As expected, a bubble point higher than 50 PSI was measured and the test passed. As shown by the pressure trace, the pressure upstream of the primary filter maintained approximately 0 PSI, and the pressure upstream of the redundant filter did not significantly exceed and was well above the bubble point shown in Figure 10. Unexpectedly, this method of the integrity test functions even though there is no barrier filter or gas filter downstream of the redundant filter. This method can also be used in different embodiments of traditional assemblies.

[0057] Integrity test of the redundant filter on a traditional assembly using the integrity tester connection as the inlet and the integrity tester connection of the primary filter as the outlet Figure 14 shows one embodiment of the flow direction of the pressurized air during the integrity test of the redundant final fill filter of a variant of a traditional redundant filtration assembly. Figure 14 shows the flow direction of the pressurized air during the integrity test of the redundant filter, whereby the air supply port of the primary filter is used as the final air outlet. As a result of this configuration, the pressurized air passes through the inlet of the redundant filter and then moves through the redundant filter via the AMPP vent port. The air exits the redundant filter and moves through the air inlet for the primary filter. This flow path may make it possible to remove the barrier filter downstream of the redundant filter.

[0058] Integrity test of the redundant filter on the efficiency-enhanced assembly using the integrity tester connection of the redundant filter as the inlet and the integrity tester connection of the primary filter as the outlet Figure 15 shows the flow direction of pressurized air during the integrity test of the redundant final fill filter of the efficiency-enhanced redundant filtration assembly. Figure 15 shows the flow direction of pressurized air during the integrity test of the redundant filter, whereby air moves through the gas filter and through the redundant filter from the integrity test machine connection for the redundant filter in order to exit the integrity test machine connection for the primary filter. As a result of this configuration, pressurized air moves through the inlet of the redundant filter and subsequently through the redundant filter via the AMPP vent port. The air exits the redundant filter and moves through the inlet of the integrity test machine connection for the primary filter via the AMPP vent port of the primary filter.

[0059] Integrity test of the redundant filter on the efficiency-enhanced assembly using the integrity test machine connection for the redundant filter as the inlet and the additional gas filter connection to the AMPP of the primary filter as the outlet Figure 16 shows the flow direction of pressurized air during the integrity test of the redundant final fill filter of the efficiency-enhanced redundant filtration assembly. Figure 16 shows the flow direction of pressurized air during the integrity test of the redundant filter, whereby air moves through the gas filter and through the redundant filter from the integrity test machine connection for the redundant filter in order to exit the additional gas filter connected to the primary filter through its AMPP. As a result of this configuration, pressurized air moves through the inlet of the redundant filter and subsequently through the redundant filter via the AMPP vent port. The air exits the redundant filter and moves through the provided additional gas filter via the AMPP vent port of the primary filter.

[0060] Integrity test of the redundant filter on the efficiency-enhanced assembly using the product inlet of the air source and the outlet of the primary filter as the outlet Figure 17 shows an embodiment of a method for testing a redundant filter, where air enters through the inlet of the filter, moves through the filter, and exits through the outlet of the primary filter. Figure 17 shows the flow direction of pressurized air during the integrity test of the redundant final fill filter of an embodiment of the efficiency-enhanced redundant filtration assembly.

[0061] Integrity test of redundant filters on an efficiency-improving assembly using the product inlet of an air source and the outlet of a primary filter as an outlet FIG. 18 shows an embodiment of a method for testing a redundant filter, where air enters through the inlet of the filter, moves through the filter, and exits through the outlet of the primary filter. FIG. 18 shows the flow direction of pressurized air during the integrity test of a redundant final fill filter of an embodiment of an efficiency-improving redundant filtration assembly.

[0062] Integrity test of redundant filters on a traditional assembly using the product inlet of an air source and the outlet of a primary filter as an outlet FIG. 19 shows an embodiment of a method for testing a redundant filter, where air enters through the inlet of the filter, moves through the filter, and exits the assembly through the air supply port for the primary filter. FIG. 19 shows the flow direction of pressurized air during the integrity test of a redundant final fill filter of an embodiment of a redundant filtration assembly according to an embodiment of the present disclosure.

[0063] In some embodiments, each container includes an impeller assembly for mixing, dispersing, homogenizing, and / or circulating one or more liquids, gases, and / or solids contained within the container, either partially or completely, inside thereof.

[0064] All ranges of formulations recited herein include the ranges therebetween and can include or exclude the endpoints. Optionally included ranges are from the recited scale, or the next smaller scale, of integer values therebetween (or including one of the original endpoints). For example, if the lower range value is 0.2, optionally included endpoints can be 0.3, 0.4,..., 1.1, 1.2, etc., as well as 1, 2, 3, etc., and if the higher range is 8, optionally included endpoints can be 7, 6, etc., as well as 7.9, 7.8, etc. One-sided boundaries such as 3 or more also include consistent boundaries (or ranges) starting from the recited scale or an integer value one lower. For example, 3 or more includes 4 or 3.1 or more.

[0065] Throughout this specification, references to "one embodiment", "a particular embodiment", "one or more embodiments", "an embodiment", or "an embodiment" indicate that a feature, structure, material, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Thus, appearances of the phrases "in one or more embodiments", "in a particular embodiment", "in one embodiment", "an embodiment", or "in an embodiment" throughout this specification are not necessarily referring to the same embodiment.

[0066] Although one embodiment has been described above, other implementations and applications are also included in the following claims. It should be understood that this specification describes one embodiment, but these embodiments merely illustrate the principles and applications of the technology described within the present disclosure. Thus, it should be further understood that many modifications may be made to the illustrative embodiments, and other arrangements and patterns may be devised without departing from the spirit and scope of the embodiments according to the present disclosure. Additionally, specific features, structures, materials, or characteristics may be combined in any suitable manner in any one or more of the embodiments.

[0067] Patent publications, patent applications, and other non-patent literature cited in this specification are hereby incorporated by reference in their entirety, as if each individual publication or reference were specifically and individually indicated to be incorporated by reference, in the portions thereof that are cited. Any patent applications for which this application claims priority are also incorporated by reference in this specification as described above for publications and references.

Claims

**Claim 1** A redundant filtration assembly comprising: A main conduit for delivering a biological product, the main conduit comprising: A primary final fill filter provided within the main conduit; A first connector and a second connector at the end of the main conduit; A first pinch clamp provided within the main conduit downstream of the first connector; A redundant final fill filter provided within the main conduit upstream of the primary final fill filter; A first air line in fluid communication with the redundant final fill filter, the first air line being joined to the main conduit and further having an integrity test connection at its distal end; An outlet directly connected to the first air line; At least one first vent bag in fluid communication with the redundant final fill filter; Two first tri-clamps provided downstream of the redundant final fill filter; Further comprising: A second pinch clamp provided between the two first tri-clamps; Two second vent bags, a second air line, and a gas filter are in fluid communication with the primary final fill filter; A third tri-clamp is provided within the main conduit downstream of the primary final fill filter; A secondary conduit is joined to the main conduit, the secondary conduit further comprising a barrier filter, the barrier filter and the secondary conduit merge with the main conduit, a third pinch clamp is provided on the main conduit, and the main conduit terminates at the second connector. A redundant filtration assembly. **Claim 2** The redundant filtration assembly according to claim 1, wherein the integrity test connection is connected to an air supply. **Claim 3** The redundant filtration assembly according to any one of claims 1 and 2, wherein the gas filter is downstream of the integrity test connection. **Claim 4** The redundant filtration assembly according to any one of claims 1 to 3, wherein there are two first vent bags. **Claim 5** The redundant filtration assembly according to any one of claims 1 to 4, further comprising a sampling bag. **Claim 6** The redundant filtration assembly according to any one of claims 4 and 5, further comprising a clamp or valve provided on the first air line between the two first vent bags. **Claim 7** The redundant filtration assembly according to any one of claims 1 to 5, wherein the outlet is a sterile multi-purpose port (AMPP). **Claim 8** The redundant filtration assembly according to any one of claims 1 to 7, further comprising a peristaltic pump having a conduit connected to the integrity test connection at a first end of the conduit. **Claim 9** The redundant filtration assembly according to any one of claims 1 to 8, further comprising two or more integrity test connection parts.

10. The redundant filtration assembly according to any one of claims 1 to 9, wherein the second end of the conduit is connected to an integrity test connection part different from the first end of the conduit.

11. The redundant filtration assembly according to any one of claims 1 to 10, further comprising a recirculation container.

12. The redundant filtration assembly according to any one of claims 1 to 11, further comprising a data acquisition system.

13. The redundant filtration assembly according to any one of claims 1 to 12, which is disposable.

14. The redundant filtration assembly according to any one of claims 1 to 12, wherein the redundant filtration system comprises stainless steel.

15. The redundant filtration assembly according to either claim 13 or claim 14, wherein the redundant filtration system comprises stainless steel and disposable components.

16. A method for integrity testing of at least one final filling filter of the redundant filtration assembly according to any one of claims 1 to 15, the method comprising: a. flowing a wetting liquid through the final filling filter; b. introducing pressurized air into the redundant filtration assembly through an air line further comprising an integrity test connection part at the distal end; c. draining the wetting liquid from the assembly; d. passing the pressurized air through a gas filter above the air inlet, an outlet, and the final filling filter before exiting the redundant filtration assembly through the outlet; e. performing at least one test selected from the group consisting of a bubble point test, a diffusion test, a water flow test, and a pressure holding test. A method comprising the above steps.

17. The method according to claim 16, wherein the outlet is a sterile multi-purpose port (AMPP) vent port.

18. The method according to any one of claims 16 and 17, further comprising arranging a clamp between the primary final filling filter and the redundant final filling filter, thereby avoiding fluid communication between the downstream side of the redundant final filling filter and the air inlet of the primary final filling filter.

19. The method according to any one of claims 16 to 18, wherein the draining step is performed using gravity drainage.

20. The method according to any one of claims 16 to 19, wherein the draining step is performed using blowdown.

21. The method according to any one of claims 16 to 20, wherein the final filling filter is a primary final filling filter.

22. The method according to any one of claims 16 to 21, wherein the final filling filter is a redundant final filling filter.

23. The method according to any one of claims 16 to 22, further comprising the step of closing the AMMP vent port of the primary final filling filter.

24. The method according to claim 23, wherein the barrier filter is the final outlet of the pressurized air.

25. The method according to any one of claims 16 to 22, further comprising the step of opening the AMMP vent port of the primary final filling filter.

26. The method according to any one of claims 16 to 22, wherein the AMMP vent port is the final outlet of the pressurized air.

27. The method according to any one of claims 16 to 22 and 26, wherein the pressurized air sequentially passes through the air supply port for the redundant final filling filter and the redundant final filling filter, and exits the redundant filtration assembly through the AMMP vent port of the redundant final filling filter.

28. The method according to any one of claims 16 to 22, wherein the pressurized air sequentially passes through the air supply port of the redundant final filling filter into the redundant final filling filter, and exits the redundant filtration assembly through the AMMP vent port of the primary final filling filter.

29. The method according to any one of claims 16 to 22, wherein the pressurized air sequentially passes through the air supply port of the redundant final filling filter into the redundant final filling filter, and exits the redundant filtration assembly through the air supply port of the primary final filling filter.

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