System and method for closure integrity testing of sealed containers at cryogenic temperatures

Abstract

A system for testing the closure integrity of a sealed container at cryogenic temperatures is provided. The system includes a sealed container filled with helium, the container having an opening sealed by a closure, a cryogenic storage container at least partially filled with a cryogenic fluid at a cryogenic temperature, a hollow tube extending through the opening of the cryogenic storage container, a fixture configured to engage with the sealed container, and a leak detection unit connected to the hollow tube. The hollow tube has a first end located outside the cryogenic storage container and an opposite second end located inside the cryogenic storage container. The fixture is configured to be removably inserted into the hollow tube through the opening at the first end of the hollow tube, so that the sealed container is located at or near the second end of the hollow tube.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application No. 62 / 771,664, filed on November 27, 2018, the disclosure of which is incorporated herein by reference in its entirety. Background Art

[0003] The present application relates to an apparatus and method for testing the closure integrity of containers (such as vials, cartridges, syringes, etc.) at cryogenic temperatures.

[0004] The integrity of the seal between the container and the closure should be considered when selecting packaging components for biological and pharmaceutical materials. These materials are often stored in stoppered glass or plastic containers (such as glass or plastic vials or syringes) with elastomeric closures. Examples of these materials include blood, serum, proteins, peptides, stem cells, DNA, and other perishable biological fluids, as well as freeze-dried or lyophilized drug products.

[0005] Containers must be able to protect materials from a variety of potential sources of contamination, including microbial ingress, moisture, and gas exchange. Therefore, the effectiveness of container closures is often tested in order to determine container closure integrity (CCI). CCI is the ability of a container closure system to provide protection and, thereby, maintain the effectiveness and sterility of materials, particularly drug products, throughout their shelf life. The ability of elastomeric sealing components (e.g., stoppers) to prevent microbial ingress into pharmaceutical containers is determined through container closure integrity testing (CCIT), which measures the integrity of the seal between the closure and the container.

[0006] The primary seal is formed at the interface of the elastomeric sealing component and the container. Assuming there are no defects in the individual packaging components, this interface represents a major point of potential packaging failure. When selecting and applying an appropriate pharmaceutical container closure system, multiple factors must be considered to ensure the integrity of the container closure.

[0007] Failures during the manufacturing process, such as improper assembly, insufficient or excessive crimping force, or design errors, can compromise the integrity of the container closure system. Therefore, it is imperative to ensure that the dimensions of the elastomeric seal components are properly matched to the container to establish adequate seal integrity. Loss of vacuum, gas ingress and exchange, pH adjustments, and contaminants can compromise the integrity of the seal, which can result in loss of sterility of the drug product, which in turn can affect product efficacy and increase the risk to patient safety.

[0008] With the growing number of high-value biologics and drug products, the requirement for reliable container closure systems has become even more important. Such biologics and drug products are often temperature sensitive and have a high potential for deterioration if not stored under appropriate conditions. It is not uncommon to store some biologics and drug products in sealed containers at temperatures as low as -80°C, and in many cases at cryogenic temperatures or even lower (e.g., down to or below -150°C), for example, to avoid deterioration or evaporative losses of these materials.

[0009] As mentioned above, the sealing components of most pharmaceutical containers are made of elastomers. A common physical property of all elastomers is the temperature at which the elastomer loses its elasticity and transforms into a rigid glass-like state. This is known as the glass transition temperature (Tg). Under ambient temperature conditions, the molecules are in a constant state of thermal motion and are constantly changing their structure, which provides flexibility and therefore the ability to form a seal against another surface. However, at the glass transition temperature, the mobility of the molecules is significantly reduced and the material becomes brittle and glassy. For example, the glass transition temperature of ordinary butyl rubber is around -65°C. Therefore, elastomeric sealing components may not maintain sealing integrity at cryogenic temperatures and may compromise the sterility of the biological or pharmaceutical product stored in the container. However, if the biological or pharmaceutical product is to be stored at cryogenic temperatures, the container closure integrity should be established under these conditions.

[0010] It would therefore be desirable to provide an apparatus and method for testing sealed containers at or below cryogenic temperatures to ensure that the integrity of the container closure is maintained under conditions to which the contents of the sealed container may be exposed, and more particularly to ensure that a plug or closure will fully seal a container opening at temperatures below -150°C, and particularly at temperatures below -180°C. It would also be helpful to ensure that a plug or closure will fully seal a container opening at temperatures below -196°C. Summary of the invention

[0011] In one embodiment, the present application relates to a system for testing the closure integrity of a sealed container at cryogenic temperatures. The system includes: a sealed container filled with helium, the container having an opening sealed by a closure; a cryogenic storage container, which is at least partially filled with a cryogenic fluid at a cryogenic temperature, the cryogenic storage container having a first end and an opposite second end, the first end having an opening; a hollow tube extending through the opening of the cryogenic storage container, the hollow tube having a first end located outside the cryogenic storage container and an opposite second end located inside the cryogenic storage container; a fixture having a first end and an opposite second end, the second end being configured to engage with the sealed container, the fixture being configured to be removably inserted into the hollow tube through the opening of the first end of the hollow tube, so that the sealed container is located at or near the second end of the hollow tube; and a leak detection unit connected to the hollow tube.

[0012] Another embodiment of the present application relates to a method for testing the closure integrity of a sealed container at cryogenic temperatures. The method includes providing a sealed container filled with helium; providing a cryogenic storage container at least partially filled with a cryogenic fluid at a cryogenic temperature, the cryogenic storage container having a first end and an opposite second end, the first end having an opening; placing a hollow tube in the opening of the cryogenic storage container, the first end of the hollow tube being located outside the cryogenic storage container, and the opposite second end being located inside the cryogenic storage container, below the filling level of the cryogenic fluid; fixing the sealed container at the distal end of a fixture; inserting the fixture into the hollow tube so that the sealed container is located at or near the second end of the hollow tube; and connecting the hollow tube to a leak detection unit and measuring the flow rate of helium escaping from the sealed container at cryogenic temperatures.

[0013] Another embodiment of the present application relates to a method for testing the closure integrity of a sealed container at cryogenic temperatures. The sealed container is prepared by the following steps: inserting an elastic plug into an opening of the container, forming a first opening and a second opening through the elastic plug body, connecting a first conduit to the first opening and engaging a first end of the first conduit with the first opening, engaging an opposite second end of the first conduit with a helium supply source, connecting a second conduit to the second opening and engaging a first end of the second conduit with the second opening, supplying helium into the container through the first conduit until the air in the container is replaced by helium, and the replaced air leaves the container through the second conduit, removing the first conduit and the second conduit from the first opening and the second opening, respectively, and covering the first opening and the second opening with a cyanoacrylate adhesive and curing the cyanoacrylate adhesive for a predetermined period of time to form a sealed container. The method also includes providing a cryogenic storage container at least partially filled with a cryogenic fluid at a cryogenic temperature, placing the sealed container in the cryogenic storage container, and measuring the flow rate of helium escaping from the sealed container at the cryogenic temperature using a leak detection unit connected to the cryogenic storage container. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The above summary as well as the following detailed description of the present application will be better understood when read in conjunction with the accompanying drawings. For the purpose of illustrating the present application, presently preferred embodiments are shown in the accompanying drawings. However, it should be understood that the present application is not limited to the precise arrangements and instrumentalities shown. In the drawings:

[0015] Figure 1 is a cross-sectional view of a conventional sealed container according to an embodiment of the present application;

[0016] Figure 2 is a perspective view of a coupler assembly of a test system according to an embodiment of the present application;

[0017] Figure 3A-3B A mechanism for securing a sealed vial for testing according to an embodiment of the present application is described;

[0018] Figures 4A-4B A mechanism for securing a sealed vial for testing according to another embodiment of the present application is described;

[0019] Figure 5A-5B A mechanism for securing a sealed vial for testing according to another embodiment of the present application is described;

[0020] Figure 6 is a perspective view of a test system according to an embodiment of the present application;

[0021] Figure 7 is a perspective view of a portion of a test system according to an embodiment of the present application in a disassembled state; and

[0022] Figure 8is a perspective view of a portion of a test system according to an embodiment of the present application in an assembled state. DETAILED DESCRIPTION

[0023] Certain terms are used in the following description for convenience only and are not limiting. The words "proximal," "distal," "upward," "downward," "bottom," and "top" indicate directions of reference in the accompanying drawings. The words "inwardly" and "outwardly" refer to directions toward and away from the geometric center of the device and designated parts thereof, respectively, according to the present application. Unless expressly provided herein, the terms "a," "an," and "the" are not limited to one element, but should be understood to mean "at least one." The terminology includes the above words, their derivatives, and words of similar meaning.

[0024] Referring to the drawings in detail, wherein like numerals represent like elements throughout the several views, Figure 1-8 A preferred embodiment of an apparatus and method for testing the closure integrity of a container closed by a closure at cryogenic temperatures is shown.

[0025] As used herein, the term "closure" may include any device that seals a container opening in the manner of a plug, plunger, or stopper, i.e., by pressing an elastic material against the entire edge of the opening to form a seal. As used herein, the term "container" may include any sealable container or holder for a material, more specifically, a container or holder that is subjected to low temperatures during processing, storage, etc. More specifically, as used herein, the term "container" may include, for example, vials, bottles, syringes, prefilled drug delivery devices, laboratory containers, etc., which have an opening that can be sealed by a closure to maintain the integrity of the contents. Those skilled in the art will appreciate that the present system / method can be used for filled or non-filled containers.

[0026] Some embodiments of the present application may be implemented at cryogenic temperatures. More specifically, embodiments of the present application may be implemented at temperatures of about -80°C or below, preferably about -150°C or below, more preferably about -180°C or below, and most preferably about -196°C or below. At cryogenic temperatures, many biological materials, such as blood, serum, proteins, peptides, stem cells, DNA, and other perishable substances may be stored to maintain long-term viability. Such storage includes dry ice storage (sublimation point -78.5°C).

[0027] The present application relates to a system and method for evaluating the CCI of a closed container. More specifically, the present application relates to a helium leak detection apparatus and method for performing CCI testing on closed containers at cryogenic temperatures. Helium leak detection provides repeatable quantitative results that are more accurate than qualitative pass / fail results.

[0028] Figure 1A conventional type of closed container that can be used in the testing system and method of the present application is shown. Figure 1 , a vial 10 containing a drug product or formulation (not shown) is shown. The vial 10 has a neck 12 having an open end 12a defined by a flange 14 having a generally annular shape. A closure or stopper 20, more specifically an elastomeric stopper, is located at the open end 12a of the vial 10 to seal the vial 10. Specifically, the stopper 20 has a stopper flange 22 and a stopper plug 24 extending downward from the flange 22. The stopper plug 24 is sealingly inserted into the opening defined by the neck 12 of the vial 10. The stopper plug 24 generally has a central cavity 26. The cavity 26 of the stopper plug 24 has a first end closed by a penetrable portion of the stopper flange 22 and a second end in open fluid communication with the contents of the vial 10, the penetrable portion preferably being disposed at the geometric center. The stopper 20 may be made of any elastic material or elastomer known to be suitable for medical applications. The vial 10 may be made of any glass, ceramic or polymer known to be suitable for medical applications.

[0029] In one embodiment, the test method of the present application is to assemble the vial 10 and the stopper 20 together (such as Figure 1 Specifically, refer to Figure 1 To prepare the vial 10 for use in the test method and apparatus, the stopper 20 first has a first opening 16 and a second opening 18. The first and second openings 16, 18 are also referred to herein as puncture sites. Preferably, the first and second openings 16, 18 have the same size, but it should be understood that the two openings 16, 18 can have different sizes. In one embodiment, the first and second openings 16, 18 are disposed at the geometric center of the stopper flange 22, but it should be understood that the openings 16, 18 can be formed at any location in the stopper flange 22. Each opening 16, 18 extends completely through the body of the stopper flange 22, so that each opening 16, 18 has a first end 16a, 18a formed at an upper surface 22a of the stopper flange 22 and a second end 16b, 18b formed at a lower surface 22b of the stopper flange 22. Each second end 16b, 18b of the first and second openings 16, 18 communicates with the interior of the vial 10.

[0030] Each opening 16, 18, and more preferably the first end 16a, 18a of each opening 16, 18 is provided with or connected to a respective conduit or line 28, 30. For example, each opening 16, 18 may be provided with or connected to a respective needle. The first conduit 28 located in or connected to the first opening 16 is used to supply an inert gas, such as helium, to the interior of the sealed vial 10. The second conduit 30 located in or connected to the second opening 18 acts as an exhaust or outlet pipe through which the air displaced by the inert gas can leave the vial 10 to prevent over-pressurization of the vial 10. Preferably, the vial 10 is prepared by filling the vial 10 with a sufficient volume of inert gas to ensure complete exhaust of the air in the vial 10. Preferably, the vial 10 is prepared by replacing the air in the vial 10 with an inert gas volume 10 times the head space of the vial 10 to ensure complete replacement of the air from the vial 10. In a preferred embodiment, the vial 10 is prepared by replacing the air in the vial 10 with 100% helium at a volume 10 times that of the head space to ensure complete replacement of the air in the vial 10. The head space (i.e., the gas space above the level of the drug) includes the cavity 26 of the stopper plug 24. It will be appreciated that the filling volume of the inert gas does not necessarily have to be 10 times that of the head space of the vial 10, but only that the volume is sufficient to ensure complete expulsion of the air in the vial 10. Preferably, the helium filling process is performed at room temperature.

[0031] Once the vial 10 is filled with helium, as described above, the first and second conduits 28, 30 are separated and removed from the respective first and second openings 16, 18. Subsequently, each of the first and second openings 16, 18 is covered with an adhesive layer 29, 31. The adhesive can be any material configured to seal the openings 16, 18. In one embodiment, the adhesive is an epoxy adhesive, more specifically a fast-curing or fast-bonding epoxy adhesive. Preferably, the epoxy adhesive comprises bisphenol A diglycidyl ether resin. Preferred commercially available epoxy adhesives are Brand No. 14250. In another embodiment, the adhesive is a glue, more specifically a fast curing or fast bonding glue. For example, the adhesive is preferably a cyanoacrylate adhesive. After the adhesive layer or coating 29, 31 is applied to the corresponding first opening and second opening 16, 18, the applied adhesive is kept undisturbed for a predetermined time to allow the adhesive to cure. Preferably, the adhesive layer or coating 29, 31 is allowed to cure for a predetermined amount of time until they are sufficiently hardened to seal the openings 16, 18, thereby forming a sealed vial 10. Depending on the type of adhesive used, the curing duration can be from a few seconds to a few minutes, or longer (e.g., about an hour), depending on the specific characteristics of the adhesive used.

[0032] Next, after the adhesive is cured, the vial 10 is pressed and / or capped and tested, or stored at a predetermined temperature, such as room temperature or cryogenic temperature, until it is ready for testing. Preferably, the sealed vial 10 can be slowly cooled to a predetermined temperature, such as -80°C, before testing at cryogenic temperature.

[0033] It should be understood that although the process of preparing a vial 10 has been described herein with respect to a single vial 10, a plurality of vials 10 may be prepared as described herein and each vial 10 may be tested individually, as described below.

[0034] It should also be understood that the vial 10 may be filled with helium by any known process and system, not necessarily the process described above.

[0035] For example, in another embodiment, the method of the present application is performed before the vial 10 and the stopper 20 are assembled together and pressed and / or capped. Specifically, in order to prepare the vial 10 for the test method and apparatus, before the stopper 20 is inserted into the open end 12a of the vial 10, an inert gas, such as helium, is preferably supplied to the interior of the vial 10 through the open end 12a at room temperature. Once the vial 10 is filled with a predetermined amount of inert gas (for example, 100% helium replaces the air in the vial 10 with 10 times the volume of the head space to ensure that the air in the vial 10 is completely replaced), the stopper 20 is placed at the open end 12a of the vial 10 to seal the vial 10, and then the sealed vial 10 is capped and pressed. Next, the vial 10 can be immediately subjected to testing or can be stored at a predetermined temperature (e.g., room temperature or cryogenic temperature) until it is ready for testing. Preferably, the sealed vial 10 can be slowly cooled to a predetermined temperature, such as -80°C, before testing at low temperatures.

[0036] In one embodiment for testing vials 10 prepared as described above, Figure 6-8. The system 60 is shown in FIG. The system 60 includes a storage container 32 and a leak detection instrument 34, more specifically a mass spectrometer. Those skilled in the art will appreciate that any known or commercially available mass spectrometer may be used. In one embodiment, the storage container 32 is a vacuum flask commonly referred to as a dewar. For temperature control, the storage container 32 may contain any known refrigerant or liquefied gas, such as but not limited to liquid nitrogen, liquid oxygen, liquid hydrogen, liquid helium, etc. Preferably, the storage container 32 is at least partially filled with liquid nitrogen so that the internal temperature of the storage container 32 is approximately -196°C. Reference Figure 3A and Figure 7 , for example, the storage container 32 has a first end 36 and an opposite second end 38. The first end 36 has an opening 40. A conduit or hollow tube 42 of a component, such as a dip tube, extends through the opening 40 of the storage container 32 so as to be securely mounted within the storage container 32. The hollow tube 42 can be configured to be removable from the storage container 32 or non-removable from the storage container 32. The size of the hollow tube 42 can be adjusted as desired to fit into any size opening 40 of the storage container 32.

[0037] In one embodiment, a coupler 54 is provided to facilitate securing the hollow tube 42 in the opening 40, such as Figure 2 The coupler 54 preferably has a generally cylindrical body that is sized and shaped to fit securely within the opening 40 and surround the hollow tube 42. More specifically, as shown in FIG. Figure 2 As shown, the coupler 54 can be formed by a plurality of cylindrical portions having different outer diameters, or can be formed by a tube having a uniform outer diameter along its entire length. In one embodiment, an adhesive can be used to fix the coupler 54 in the opening 40. In another embodiment, the coupler 54 is fixed in the opening 40 by friction fit. The coupler 54 also has a cylindrical hole 56 extending through its body. The size and shape of the hole 56 can accommodate the hollow tube 42 therein, so the coupler 54 can increase the stability of the hollow tube 42 in the opening 40 of the storage container 32. The coupler 54 also preferably includes at least one exhaust hole or opening 58 for exhausting the gas contained in the storage container 32. In particular, since the liquid nitrogen is continuously pressurized and produces gas, the exhaust hole 58 in the coupler 54 is configured to exhaust the generated gas. It should be understood that a plurality of exhaust holes 58 can be provided in the coupler 54.

[0038] refer to Figure 7, the above-mentioned assembly may include a hollow tube 42 and an adapter 43. The adapter 43 may be configured as a T-shaped joint and is detachably connected to one end of the hollow tube 42. The joint is preferably fixed with a mechanical connector 62 (e.g., a clip). The hollow tube 42 and the adapter 43 may be made of metal or plastic. Preferably, the hollow tube 42 and the adapter 43 are made of a metal such as stainless steel. The hollow tube 42 has a first end connected to the adapter 43 and configured to be located outside the storage container 32 and an opposite second end 45 configured to be located inside the storage container 32. More specifically, the second end 45 of the hollow tube 42 is located below the filling level of liquid nitrogen in the storage container 32. The adapter 43 includes a first leg 64 on the opposite side of the T-shaped joint, opposite to a second leg 66 connected to the hollow tube 42. The first and second legs 64, 66 are preferably formed as hollow tubes or tubes. The first leg 64 of the adapter 43 preferably includes an open end, which is configured to be closed with a cap 70, as will be described in more detail below.

[0039] It is understood that the assembly may only include an adapter configured as a T-joint, wherein the first branch and the second branch of the adapter are formed by a hollow tube, the first open end of the hollow tube corresponds to the first open end of the first branch 64 of the adapter 43, and the second open end of the hollow tube corresponds to the second end 45 of the follower tube 42. Such an assembly eliminates the need for a mechanical connector 62.

[0040] The hollow tube 42 is connected to the mass spectrometer 34 via an adapter 43 and a conduit 49 (see Figure 6 and 8 ). More specifically, the conduit 49 is releasably connected to the third branch 68 of the adapter 43, which is perpendicular to the first branch 64 and the second branch 66. The third branch 68 is also preferably formed as a hollow tube. The conduit 49 is used to connect the hollow tube 42 to the mass spectrometer 34 fluid. Figure 6 As shown, the conduit 49 has a first end 72 that can be removably connected to the adapter 43 by another mechanical connector 53 (e.g., a clamp) and an opposite second end 53 that is connected to the mass spectrometer 34. The mass spectrometer 34 is preferably a helium mass spectrometer. Preferably, the mass spectrometer 34 is calibrated according to a NIST traceable leak standard before being used to analyze the vial 10.

[0041] In one embodiment, the device 60 also includes a fixture 46 mounted within the hollow tube 42. More specifically, the fixture 46 is configured to be removably inserted into the hollow tube 42 and the adapter 43 through the open end of the first branch 64 after removing the cap 70. The cap 70 can be removably attached to the end of the first branch 64 by any means known to those skilled in the art. The preferred method is a clip 44. In another embodiment, the cap 70 can be threadedly connected to the end of the first branch 64. The fixture 46 can be a rod, tube or wire configured to hold the sealed vial 10 in the hollow tube 42 for placement in the storage container 10 for testing. The fixture 46 has a first end 47 and an opposite second end 50. The second end 50 of the fixture 46 is configured to engage or hold the sealed vial 10.

[0042] In one embodiment, the second end 50 includes or is formed as a container or cavity configured to receive a vial 10, more specifically, a sealed vial 10 filled with helium. For example, the second end 50 may include a cup-shaped container (not shown) sized and shaped to receive a sealed vial 10 for testing therein.

[0043] As another example, Figure 3A-3B As shown, the securing device 46 may be in the form of a flexible wire having a second end 50 that is wrapped or coiled around the sealed vial 10 to secure the vial 10 for testing.

[0044] As another example, Figures 4A-4B As shown, the securing device 46 can be in the form of a flexible plastic (e.g., nylon) wire or rope, the second end 50 of which is tied or otherwise secured around the sealed vial 10, particularly around the neck 12 of the sealed vial 10, to secure the vial 10 and lower the vial 10 into the storage container 32 for testing.

[0045] As another example, Figure 5A-5B As shown, the fixture 46 may be in the form of a tube (metal or plastic) having a second end 50 including a securing mechanism 60 including a plurality of gripping fingers or claws for gripping a portion of the sealed vial 10 to secure the vial 10 for testing.

[0046] although Figures 3A-5B Some specific examples of the fixture 46 are provided in the following. More specifically, a mechanism for securing the sealed vial 10 is provided at the second end 50 of the fixture 46. It will be understood by those skilled in the art that the fixture 46 and the mechanism provided at the second end 50 thereof can take any form capable of securing the sealed vial 10 and lowering it into the storage container 32 for testing purposes.

[0047] To implement the test method, the hollow tube 42 is installed in the opening 40 of the storage container 32 so that the coupler 54 is securely installed in the opening 40, the second end 45 of the hollow tube 42 is located inside the storage container 32, below the filling level of the liquid nitrogen, and the first end of the hollow tube 42 is located outside the storage container 32 and connected to the adapter 43. Next, the helium-filled sealed vial 10, preferably prepared as described above, is fixed at the second end 50 of the fixture 46, and then the fixture 46 is inserted into the hollow tube 42 through the open end of the first branch 64 of the adapter 43, toward the second end 45, until the vial 10 is located at or near the second end 45 of the hollow tube 42, so as to place the vial 10 and its drug content at a cryogenic temperature. In one embodiment, the first end 47 of the fixture 46 is fixed to the first branch 64 of the adapter 43, and the open end of the first branch 64 of the adapter 43 is then closed by the cap 70 and the clamp 44. In another embodiment, the first end 47 of the fixture 46 can be secured to or integrally formed with a cap 70 that is configured to close the open end of the first branch 64 of the adapter 43. In such an embodiment, the cap 70 can be grasped, the fixture 46 can be inserted into the adapter 43 and the hollow tube 42 through the initial open end of the first branch 64 of the adapter 43, and then the cap 70 can be placed to close the open end of the first branch 64.

[0048] In another embodiment (not shown), the storage container 32 may be eliminated by incorporating a cooling system into the fixture 46. For example, in one embodiment, the second end of the fixture 46 where the vial 10 is placed may be provided with a jacket or coil that wraps around the vial 10, and a liquefied gas (e.g., liquid nitrogen) flows through the jacket or coil to cool the vial 10 to a cryogenic temperature. In another embodiment, the adapter 43 and / or the hollow tube 42 may be equipped with a jacket or coil through which a liquefied gas or some other coolant may flow.

[0049] It is understood that the temperature within the storage container 32 may vary depending on the coolant used. For example, the internal temperature of the storage container 32 is preferably about -150°C or lower, more preferably about -180°C or lower, and most preferably about -196°C (i.e., the boiling point of liquid nitrogen) or lower.

[0050] As described above, once the sealed vial 10 is secured within the storage container 32, operation of the mass spectrometer 34 begins. The mass spectrometer 34 places the vial 10 under vacuum and measures the helium escaping from the vial 10 at a cryogenic temperature, more preferably at -196°C. The partial pressure of the helium in the leak detector is measured by the mass spectrometer 34, and the "leakage" of the vial 10 is displayed as a leak rate, which is a quantitative measurement. After the leak rate is determined, the vial 10 is heated to room temperature. Then, a calibrated headspace analyzer probe (not shown) is used to measure the helium concentration within the vial 10 to determine the amount of helium remaining in the vial 10. The helium concentration and the measured helium leak rate are then used to calculate the actual helium leak rate (cc / sec) of the vial 10. The helium leak rate is related to the amount of helium that has leaked.

[0051] According to the embodiment of the present application, the helium leakage rate of the prepared vials at -180°C is about E -9 To E -10 Standard cc / s. In comparison, the leakage rate of an equivalent vial filled with helium at room temperature is E -7 To E -8 When comparing room temperature samples with samples analyzed at -180°C, the leak rates measured according to the examples of the present application show a significant reduction.

[0052] It should be understood that although the discussion herein primarily relates to vials, the container may include any container suitable for storing or containing a biological or pharmaceutical product, such as a syringe, cartridge, blister pack, and the like.

[0053] It should also be understood that other gases may be used with the systems / methods of the present application, depending on the type of analytical instrumentation used to detect the gas filling the headspace of the container, including but not limited to gas chromatography / mass spectrometry (GC / MS) and emission spectroscopy.

[0054] Example

[0055] Using the system and method according to the embodiment of the present application and the control sample, a test was conducted at -180°C and a total of 80 vials were tested. The vials were 2 mL or 10 mL vials made of cyclic olefin polymeric material (Crystal (CZ), manufactured by Daikyo Seiko Co., Ltd.). Closures were either 13 mm or 20 mm halogenated butyl rubber stoppers. All vials were sealed and prepared as described above (i.e., all sample vials, positive control vials, and negative control vials were filled with helium and air was purged from the vials) and then press-fit closed. The vials were then individually analyzed at cryogenic temperatures (e.g., -180°C) to determine the helium leak rate for each vial.

[0056] More specifically, after calibrating the helium mass spectrometer (SIMS1284+ Seal Integrity Monitoring System manufactured by Leak Detection Associates) and confirming the suitability of the system, i.e., after confirming that the calibration is valid, each vial is placed in a storage container (i.e., Dewar flask) for helium leak analysis. Each storage container used to test 2mL and 10mL vials is connected to the helium mass spectrometer. During the entire helium leak analysis process, -180°C is maintained on the sample. The helium mass spectrometer draws a vacuum on the sample, producing a quantitative leak rate in standard cubic centimeters per second. If the instrument cannot successfully draw a vacuum on the sample, it is considered a "serious leak." This procedure is performed for both 2mL and 10mL vial sizes.

[0057] On each day of analysis, the same five positive controls with 2 μm pores in the vial body were analyzed along with 20 new vials. Validation of the procedure was performed by the primary analyst and the secondary analyst. The primary analyst performed the analysis of the precision, robustness, specificity, and method detection limit (MDL) portions of the procedure. The secondary analyst performed the analysis of intermediate precision. The results of the primary and secondary analysts are shown in Tables 1-4. The criterion for a successful sample was less than or equal to 1.9E -6 Standard cc / s.

[0058] Accuracy

[0059] On the first day (Day 1), five (5) 2 μm positive controls and twenty (20) samples were analyzed using the above-described system and method. The results are shown in Table 1, where "MHLR" represents the measured helium leak rate, or the leak rate determined by vacuum testing, without correction for helium concentration.

[0060] Intermediate accuracy

[0061] On the second day (Day 2), the secondary analyst followed the same procedures and methods of the present system 60, using the same positive controls as the primary analyst, but using a different helium mass spectrometer and using different twenty (20) sample containers. The results are shown in Table 1.

[0062] Specificity, MDL, instrument robustness, and sample type robustness

[0063] On the third day (Day 3), the primary analyst followed the same procedure of the system and method of the present application using the same positive control, and the results are shown in Table 1.

[0064] The sample type robustness was performed by analyzing 2 mL sample containers and the results are shown in Table 2.

[0065] Specificity was determined by confirming that the instrument was able to detect the difference between passing and failing containers. The lowest limit of detection was demonstrated to be 2 μm.

[0066] The robustness of the instrument was also performed and demonstrated by performing analyses using 50 and 70 second data acquisition times as well as the nominal 60 second data acquisition time. The results show that the instrument is robust in its ability to produce the expected results given any possible variations in instrument data acquisition. These results are presented in Tables 3 and 4.

[0067] All vials tested under this application passed a 1.9E -6 Leak rate standard of standard cc / s, while positive control exceeds 1.9E -6 Standard cc / s.

[0068] Table 1: Results for 10 mL CZ vials

[0069]

[0070] Table 2: Results for 2 mL CZ vials (Sample Type Robustness)

[0071] Analyst 1 Vial# MHLR (standard cc / s) 235285 Serious leak 235291 4.2E-4 235295 Serious leak 235301 2.5E-4 235303 Serious leak 1 4.8E-10 2 4.0E-10 3 4.0E-10 4 3.6E-10 5 3.9E-10 6 3.9E-10 7 3.5E-10 8 3.4E-10 9 3.5E-10 10 3.9E-10 11 3.4E-10 12 4.2E-10 13 4.6E-10 14 3.8E-10 15 3.4E-10 16 4.1E-10 17 4.4E-10 18 4.3E-10 19 3.6E-10 20 2.7E-10

[0072] (235285, 235291, 235295, 235301 and 235303 represent positive controls 1, 2, 3, 4 and 5 respectively)

[0073] Table 3: Instrument robustness – 50 second data acquisition time

[0074] Vial# MHLR (standard cc / s)#1800005127 1 7.6E-10 2 1.3E-9 3 1.6E-9 4 1.2E-9 5 1.1E-9 6 9.7E-10 7 1.0E-7 8 6.9E-10 9 8.6E-10 10 6.2E-10

[0075] Table 4: Instrument robustness – 70 second data acquisition time

[0076] Vial# MHLR (standard cc / s)#1800005127 1 3.2E-9 2 2.2E-9 3 1.9E-9 4 5.2E-8 5 1.1E-9 6 1.3E-9 7 1.2E-9 8 1.1E-9 9 1.0E-9 10 7.4E-10

[0077] Those skilled in the art will appreciate that the above embodiments may be modified without departing from the broad inventive concept of the above embodiments. Therefore, it should be understood that the present application is not limited to the specific embodiments disclosed, but is intended to cover modifications within the spirit and scope of the present application as defined by the appended claims.

Claims

1. A system for testing the closure integrity of a sealed container at low temperatures, the system comprising: a sealed container containing helium and having an opening sealed by a closure; a cryogenic storage container at least partially filled with a cryogenic fluid at a cryogenic temperature, the cryogenic storage container having a first end and an opposing second end, the first end being provided with an opening; a hollow tube extending through the opening of the cryogenic storage container, the hollow tube having a first end located outside the cryogenic storage container and an opposing second end located inside the cryogenic storage container; a fixture having a first end and an opposite second end, the second end being configured to engage the sealed container, the fixture being configured to be removably inserted into the hollow tube through the opening at the first end of the hollow tube such that the sealed container is located at or near the second end of the hollow tube; and The leakage detection unit is connected to the hollow tube.

2. The system of claim 1, wherein the cryogenic temperature is approximately -150°C or below.

3. The system of claim 1, wherein the cryogenic fluid is liquid nitrogen.

4. The system of claim 1, wherein the cryogenic storage container is a Dewar flask.

5. The system of claim 1, further comprising a coupler secured within the opening of the cryogenic storage container, the coupler surrounding at least a portion of the hollow tube.

6. The system of claim 5, wherein the coupler includes at least one exhaust port for exhausting gas generated by the cryogenic fluid.

7. The system of claim 1, wherein the securing device comprises a flexible wire, a portion of the wire being wrapped around at least a portion of the sealed container.

8. The system of claim 1, wherein the second end of the fixture comprises a plurality of claws for gripping a portion of the sealed container.

9. The system of claim 1, wherein the leak detection unit is a helium mass spectrometer.

10. A method for testing the closure integrity of a sealed container at cryogenic temperatures, the method comprising: Provide a sealed container filled with helium; providing a cryogenic storage container at least partially filled with a cryogenic fluid at a cryogenic temperature, the cryogenic storage container having a first end and an opposing second end, the first end being provided with an opening; placing a hollow tube within the opening of the cryogenic storage container, with a first end of the hollow tube located outside the cryogenic storage container and an opposing second end located inside the cryogenic storage container below a fill level of the cryogenic fluid; Fixing the sealed container at the distal end of the fixing device; inserting the fixture into the hollow tube so that the sealed container is located at or near the second end of the hollow tube; and The hollow tube is connected to a leak detection unit, and the flow rate of helium escaping from the sealed container at cryogenic temperature is measured.

11. The method of claim 10, wherein the cryogenic temperature is about -150°C or below.

12. The method of claim 10, wherein the cryogenic fluid is liquid nitrogen.

13. The method of claim 10, wherein the cryogenic storage container is a Dewar flask. The method of claim 10 , wherein the leak detection unit is a helium mass spectrometer.

15. A method for testing the closure integrity of a sealed container at cryogenic temperatures, the method comprising: Prepare the sealed container by following these steps: Insert the elastic plug into the opening of the container, forming a first opening and a second opening through the body of the elastomeric plug, connecting a first conduit to the first opening, a first end of the first conduit engaging the first opening and an opposing second end of the first conduit engaging a helium supply, connecting a second conduit to the second opening, the first end of the second conduit engaging the second opening, providing helium gas into the container through the first conduit until the air in the container is replaced by the helium gas and the replaced air leaves the container through the second conduit, removing the first conduit and the second conduit from the first opening and the second opening, respectively, and covering the first opening and the second opening with a cyanoacrylate adhesive and curing the cyanoacrylate adhesive for a predetermined time, thereby forming the sealed container; providing a cryogenic storage container at least partially filled with a cryogenic fluid at a cryogenic temperature; placing the sealed container in the low-temperature storage container; and A leak detection unit is used in connection with the cryogenic storage container and measures the flow rate of helium escaping from the sealed container at the cryogenic temperature.

16. The method according to claim 15, further comprising: placing a hollow tube through the opening of the cryogenic storage container, the hollow tube having a first end located outside the cryogenic storage container and an opposing second end located inside the cryogenic storage container, the second end being located below a fill level of the cryogenic fluid; fixing the sealed container at the distal end of the fixing device; and The fixture is inserted into the hollow tube so that the sealed container is located at or near the second end of the hollow tube.

17. The method of claim 15, wherein the cryogenic temperature is about -150°C or below.

18. The method of claim 15, wherein the cryogenic fluid is liquid nitrogen.

19. The method of claim 15, wherein the cryogenic storage container is a Dewar flask.

20. The method of claim 15, wherein the leak detection unit is a helium mass spectrometer.

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