AU2019100522A4

AU2019100522A4 - Vial stopper

Info

Publication number: AU2019100522A4
Application number: AU2019100522A
Authority: AU
Inventors: Craig James Miller
Original assignee: BTF Pty Ltd
Current assignee: BTF Pty Ltd
Priority date: 2018-06-29
Filing date: 2019-05-14
Publication date: 2019-06-27
Anticipated expiration: 2027-05-14

Abstract

VIAL STOPPER Abstract A stopper (200) configured to be inserted into and seal a vial (300) having a top face (320), an opening (310), and a neck (330), the stopper (200)comprising: a cap (210) having an upper surface (211) and a lower surface (212); a shaft (220) protruding from the lower surface (212) of the cap (210) and configured to be inserted into the opening (310) of the vial (300); three legs (230) extending from the shaft (220), each leg having a protrusion (250); and a sealing means (240) extending around and protruding from the shaft (220). The protrusions (250) secure the stopper (200) in the vial (300) when the protrusions (250) are disposed past the neck (330) inside the vial (300). The sealing means (240) being configured to engage and create a seal with an inner surface of the neck (330) when the shaft (220) is inserted into the opening (310) of the vial (300). Figure 1

Description

VIAL STOPPER

FIELD OF THE INVENTION [001] The technology relates to a stopper for sealing of glass vials under vacuum or filled with an injected gas for pharmaceutical, medical, biological, and other related processes and products.

BACKGROUND TO THE INVENTION [002] Glass vials are used extensively in the packaging and storage of biological materials, microorganisms, drugs and vaccines. Rubber stoppers are inserted into the glass vials to seal the contents as described below. The top section of the rubber stopper, herein called the cap, is thin so that a needle can easily penetrate the rubber and can do so without shredding the rubber into the injectable fluid within the vial. The glass vials are typically cylindrical with a necked section near the open end of the vial. Typically, an aluminium cap is crimped down onto the rubber stopper to seal the stopper onto the top of the glass vial. The neck has a diameter which is reduced from the outside diameter of the vial to allow a crimping cover to be wrapped over the rubber stopper cap after it has been inserted into the vial opening. The vial opening is herein called the throat. The crimped cover is secured by bending into the necked area on the vial. The section of the stopper that is inserted into the vial, called herein the shaft, has a diameter slightly greater than the throat diameter. The rubber stopper inserted into the vial is intended to maintain a seal on the top surface of the glass vial.

[003] Stoppers that have a stopper cap diameter of 13 mm or larger have a variety of leg configurations, from one to four legs for vacuum or gas sealing applications. To remove or replace the air in a vial, stoppers of all sizes are partially inserted into the vial throat and the vial is placed in a chamber that removes air or removes and replaces air with another gas. In this partially inserted position, the gap in the shaft for a single leg stopper or the gaps between the legs for multi-legged stoppers, allow air to be drawn out of the vial by a vacuum pump connected to the chamber. The legs are typically stiff enough to hold the stopper in this position throughout the air removal process. When the air has been removed or replaced with another gas, the shelves of the vacuum chamber close together and press the stoppers fully into the vials. The stopper provides a temporary seal until an aluminium cover is crimped over the end of the stopper to lock the stopper in and create a seal between the top face of the vial and the bottom side of the cap of the stopper.

2019100522 14 May 2019 [004] Many applications employ small glass vials. Small vial stoppers are designated as 13 D in the industry, with a cap diameter of 13 mm standard in the industry. For small vials, typically the cap end of the stopper measures 2.4 mm in thickness. Small vials are typically cylindrical, measuring 32 mm in height, with a body diameter of 14.75 mm and a throat diameter of 7.0 mm. The section of the stopper that is inserted into the vial, the shaft, has a diameter slightly greater than 7.0 mm, typically about 7.5 mm. As with all rubber stopper applications, the vacuum or gas seal is intended to reside on the top face of the glass vial, not on the shaft in the throat of the vial. These small stoppers typically have no more than two separated legs for vacuum or gas applications, having either a single leg with a gap on one side or two legs with gaps between the legs to allow air to be suctioned out of the vial while the stopper is partially inserted into the vial. Particularly for the two leg design, the legs must be stiff enough to hold the stopper in a partially inserted position throughout the air removal process. The two leg design tends to buckle and lift the edge of the cap at the two points of the vial face which are in line with the gap between the legs.

[005] The glass vials are produced from standard glass tubing which is heated typically by gas flames and formed into a container closed at one end and necked at the other end which is open. The necking process introduces a taper in the throat of the vial which decreases the throat diameter moving downward from the vial face.

[006] For all stopper designs, force is required to press the stoppers into the fully inserted position for sealing the vials. The stopper fully inserted into the vial is herein designated as the vial-stopper. Since the vial height tolerance is ± 0.35 mm and the stopper cap thickness tolerance is ± 0.25 mm typically in the industry, the overall height of the vial plus the inserted stopper can vary significantly. This variation in overall height means that when the vacuum suctioning operation is completed and the shelves of the vacuum system come together to press the stoppers into the vials, the force from the shelf pressing on the stopper caps can vary significantly depending on how much compression of the stopper caps has taken place on the highest standing stopper-vials.

[007] The present inventor has developed an improved stopper for a vial that can be used to maintain a vacuum or injected gas in a vial without a crimped cover.

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SUMMARY OF INVENTION [008] In a first aspect, the present invention provides a stopper configured to be inserted into and seal a vial having a top face, an opening, and a neck, the stopper comprising:

a cap having an upper surface and a lower surface;

a shaft protruding from the lower surface of the cap and configured to be inserted into the opening of the vial;

three legs extending from the shaft, each leg having a protrusion; and a sealing means extending around and protruding from the shaft, wherein:

the protrusions secure the stopper in the vial when the protrusions are disposed past the neck inside the vial; and the sealing means is configured to engage and create a seal with an inner surface of the neck when the shaft is inserted into the opening of the vial.

[009] In a second aspect, the present invention provides a stopper for maintaining a vacuum or gas seal of a vial having a top face, an opening, and a neck, the stopper comprising:

a cap having an upper surface and a lower surface;

a shaft extending longitudinally from the cap configured for insertion into the opening of the vial;

three legs equispaced around the shaft, the three legs configured to hold the stopper partially inserted in a vial to form passageways between the legs to allow movement of air out of the vial under vacuum and, in use, extend past the neck of the vial when the stopper is fully inserted in a vial;

a protrusion on each of the legs; and a sealing means protruding from the shaft proximal to the cap and above the legs to provide a seal in the throat of the vial as the lower surface of the cap is moved adjacent to the top face of the vial to maintain a vacuum or gas in the vial;

wherein the stopper is a unitary product formed from a flexible and resilient rubber material;

wherein the lower surface on the cap further provides a seal when the stopper is positioned in the vial and the cap abuts the top face of the vial; and wherein the stopper provides a seal and allows a vacuum or gas to be maintained in a vial without requiring a crimped-on metal cap to secure the stopper on the vial.

[010] In an embodiment, each of the legs are deformable to facilitate insertion of the stopper into the vial.

2019100522 14 May 2019 [011] In an embodiment, the cap is configured to be pierceable by a needle.

[012] In a third aspect, the present invention provides a method of sealing a vial having a top face, an opening, and a neck, the method comprising the steps of:

inserting the legs of a stopper according to any one of claims 1 to 4 into the opening of the vial such that each of the protrusions are disposed past the neck inside the vial to form a passageway to the inside of the vial between each of the legs;

removing a gas from the inside of the vial through one or more of the passageways; and inserting the shaft into the opening such that the sealing means engages and creates a seal with an inner surface of the neck of the vial.

[013] In an embodiment, a further seal is created between the lower surface of the cap and the top face of the vial when the shaft is inserted into the opening of the vial and the lower surface of the cap abuts the top face of the vial.

[014] There is also disclosed a stopper for maintaining a vacuum or gas seal of a vial having a top face, an opening, and a neck, the stopper comprising:

a cap having an upper surface and a lower surface;

a shaft extending from the cap and configured to be inserted into the opening of the vial;

three legs protruding from the shaft; and a sealing means protruding from the shaft proximal to the cap, the sealing means configured to provide a seal in the throat of the vial as the lower surface of the cap is positioned adjacent to the top face of the vial to maintain a vacuum or gas in the vial.

[015] In an embodiment, the lower surface of the cap further provides a seal between the lower surface of the cap and the top face of the vial when the stopper is positioned in the vial and the cap abuts the top face of the vial.

[016] In an embodiment, when the stopper is inserted into the vial and the lower surface of the cap abuts the top face of the vial, the legs extend past the neck of the vial.

[017] In an embodiment, the three legs are deformable to facilitate insertion of the stopper in the vial.

[018] In an embodiment, the three legs are equispaced around the shaft of the stopper.

2019100522 14 May 2019 [019] In an embodiment, when the stopper is partially inserted into the vial, the three legs are configured to hold the stopper in the vial and form a passageway between each of the legs to allow movement of air out of the vial under vacuum.

[020] In an embodiment, when the stopper is inserted into the vial and the lower surface of the cap is positioned adjacent the top face of the vial, the stopper seal the vial and allows a vacuum or gas to be maintained in the vial without requiring a crimped-on metal cap to secure the stopper in the vial.

[021] In an embodiment, the sealing means is configured to frictionally engage the interior of the vial in a region of the neck.

[022] In an embodiment, the sealing means is formed as a compressible ring around the shaft.

[023] In an embodiment, the stopper further comprises a lower ring about the legs to assist in positioning the legs in a vial.

[024] In an embodiment, the cap is pierceable by a needle to gain access to the interior of the vial.

[025] In an embodiment, the stopper is configured to be positioned into sealing engagement with a vial after air is either removed from the vial or replaced with an injected gas such that the sealing means engages an inner surface of the neck of the vial to seal the vial and maintain a vacuum or injected gas in the vial.

[026] In an embodiment, the lower surface of the cap engages the top face of the vial to provide a seal between the lower surface of the cap and the top face of the vial to maintain the vacuum or injected gas in the vial.

[027] There is also disclosed a method for sealing a vial having a top face, an opening, a neck, and an interior, the method comprising:

providing a stopper according to the first or second aspect;

partially inserting the stopper into the opening of the vial to form a passageway to the interior of the vial between each of the legs of the stopper;

withdrawing air from and/or inserting gas into the vial via one or more of the passageways; and positioning the stopper into sealing engagement with the vial such that the sealing means engages an inner surface of the neck of the vial to seal the vial.

2019100522 14 May 2019 [028] Throughout this specification, unless the context requires otherwise, the word comprise, or variations such as comprises or comprising, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

[029] Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this specification.

[030] In order that the present invention may be more clearly understood, preferred embodiments will be described with reference to the following drawings and examples.

BRIEF DESCRIPTION OF THE DRAWINGS [031] A preferred embodiment of the present invention will now be described, by way of example only, with reference to the accompanying figures, in which:

[032] Figure 1 is a perspective view of a vial stopper in accordance with an embodiment of the present invention;

[033] Figure 2 is a top view of the vial stopper shown in Figure 1;

[034] Figure 3 is a bottom view of the vial stopper shown in Figure 1;

[035] Figure 4 is a side view of the vial stopper shown in Figure 1;

[036] Figure 5 is another side view of the vial stopper shown in Figure 1;

[037] Figure 6 is a cross section view of the vial stopper shown in Figure 3; and [038] Figure 7 is a generic vial.

DETAILED DESCRIPTION OF THE DRAWINGS [039] As illustrated in the drawings, a stopper 200 for sealing of a vial 300 having a throat 310, atop face 320, and a neck 330. The throat 310 extends inside the vial 300 slightly beyond the neck 330 on the outside of the vial 300. The interior of the vial 300 then expands.

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The vial 300 is a typical glass vial used extensively in the packaging and storage of drugs and vaccines.

[040] The stopper 200 comprises a cap 210 having an upper surface 211 and a lower surface 212. The upper surface 210 is configured to allow a needle to easily penetrate the stopper 200 without shredding the cap 210 into the interior of the vial 300.

[041] The stopper 200 further comprises a shaft 220 protruding from the lower surface 212 of the cap 200 and is configured to be inserted into the throat 310 of the vial 300. The stopper 200 further comprises three legs 230 extending from the shaft 220. The three legs 230 are equispaced around the shaft 220 of the stopper 200.

[042] The stopper 200 further comprises a sealing means 240 in the form of a ring extending around and protruding from the shaft 220 proximal to the cap 210 to maintain a vacuum or gas in the vial 300 as the lower surface 212 of the cap 210 is positioned adjacent to the top face 320 of the vial 300. The sealing means 240 is generally referred to herein as upper ring 240.

[043] Each leg 230 has a protrusion 250 and together the protrusions form a lower ring, which will be referred to as lower ring 250.

Cap [044] The vial stopper 200 is a unitary product, and may be constructed of any suitable material such as a flexible and resilient rubber. The rubber composition is a standard formulation for the pharmaceutical industry. The main compositions of the rubber are typically: bromobutyl or chlorobutyl rubber, kaolin, and a vulcanizing agent. The breakdown by weight varies slightly between suppliers, primarily in the amount of kaolin. Typical analysis for prime components by weight from one supplier:

Brominated Butyl Rubber 54.8%

Calcine Kaolin 39.2%

Vulcanizing Agent 0.25%

Carbon Black 0.15% [045] Typical analysis by weight from another supplier:

Brominated Butyl Rubber 55%

Calcine Kaolin 43%

Vulcanizing Agent 0.5%

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Carbon Black 0.04% [046] The lower surface 212 of the cap 210 may further assist in maintaining the vacuum or gas in the vial 300 when the stopper 200 is positioned in the vial 300 and the cap surface 212 abuts the top face 320 of the vial 300. However, the primary sealing is the sealing means 240 of the shaft 220 of the stopper 200. The stopper 200 maintains the vacuum or gas in the vial 300 without requiring a crimped-on metal cap over the cap 210 to secure the stopper 200 in the vial 300.

[047] The cap 210 is configured to be pierceable by a needle to gain access to the interior and therefore the contents of the vial 300. The thickness of the cap 210 is able to provide the vacuum or gas seal while still allowing the needle to pierce therethrough. Typically, in the industry, the cap thickness is 2.4 mm. In a preferred embodiment, the thickness of the cap 210 of the stopper 200 measures 4.0 mm. The thicker cap 210 varies the overall length of the stopper 200 relative to existing stoppers.

[048] The lower surface 212 of the cap 210 engages the top face 320 of the vial 300 and can provide a further seal to assist in maintaining the vacuum or containing the gas in the vial 300. The variation in overall height of vial 300 plus stopper 200 means that when the air removal operation is complete, and the shelves of the vacuum system come together to press the stoppers 200 into the vials 300, the force from the shelf pressing on the cap 210 of the stopper 200 can vary significantly depending on how much compression of the caps 210 has taken place on the highest standing stopper-vials. The stopper 200 can act like a spring to resist compression. The compression force for the stopper 200 is linear over a very short range whose length depends on the thickness of the cap 210. Within the allowable height variation, the total force required for full insertion of all the stoppers 200 may become larger than the vacuum system shelves can provide. Using a thicker cap 210 on the stopper 200 can prevent the insertion force increasing exponentially on the higher standing stoppers 200 while the shorter standing stoppers 200 are not yet fully sealed.

[049] Crimping an aluminium cover over the stopper 200 to achieve stable sealing is not necessary, since sealing is achieved and maintained by the upper ring 240 of the shaft 220 bearing against the inner surface of the neck 330 of the vial 300, and the lower surface 212 of the cap 210 bearing against the top face 320 of the vial 300 providing a further level of sealing.

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Shaft [050] When the stopper 200 is inserted into the throat 310 of the vial 300 such that the lower surface of the cap 210 abuts the top face 320 of the vial 300, the legs 230 extend past the neck 330 of the vial 300 to where the interior of the vial 300 expands. The shaft 220 typically has a diameter of about 7.5 mm to be slightly greater than the diameter of the throat

310 of the vial 300, typically being around about 7.0 mm.

Sealing means [051] The upper ring 240 is configured to frictionally engage the interior of the vial 300 in a region of the throat 310. The sealing means 240 is formed as a compressible ring around the shaft 220, as described above.

[052] The width of the upper ring 240 is extended on the shaft 220 to make a robust seal between the shaft 220 and the throat 310 of the vial 300 when the stopper 200 is inserted into the throat 310 of the vial 300. The width of the upper ring 240 may be about 2.0 mm. The upper ring 240 may be positioned about 1.4 mm from the lower face 212 of the cap 210. In another embodiment, the upper ring 240 may be positioned about 1.0 mm from the lower face 212 of the cap 210. In one embodiment, the upper ring 240 may be about 7.8 mm in diameter, or may be about 8.0 mm in another embodiment.

[053] In an embodiment, the sealing means 240 has a substantially smooth face to substantially engage with the throat 310 of the vial 300.

[054] Glass vials 300 may be made by Gerresheimer AG and supplied from the vial manufacturer in racks that hold 371 pieces. The vials 300 are tightly packed with alternating rows of seven vials and six vials. There are typically 29 rows of seven vials and 28 rows of six vials. Multiple racks are run simultaneously in the freeze dryer, depending on number of shelves, shelf size, and production requirements.

[055] Before running the freeze dryer cycle, stoppers 200 are partially inserted into the vials 300, thereby forming a passageway between each leg that allows air to be removed from the interior of the vials 300. The freeze dryer operation provides a controlled temperature and pressure cycle to remove moisture and create a vacuum in the vials 300. At the end of the freeze dryer cycle, the shelves close together to fully press the stoppers 200 into the vials 300 and seal the vacuum or injected gas in the vials 300. Air is then allowed into the freeze dryer and the freeze dryer is opened and the racks removed.

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Legs [056] In an embodiment, extending from the lower section of the shaft 220 are three legs

230 that are deformable to facilitate insertion of the stopper 200 into the vial 300. When the stopper 200 is partially inserted into a vial 300, the three legs 230 are configured to hold the stopper 200 in the vial 300 and form a passageway to the interior of the vial 300 between each of the legs 230 that allow movement of air out of the vial 300 under vacuum.

[057] In an embodiment, when the stopper is partially inserted into a vial 300, the three legs 230 distribute side forces against the vial 300 better than a stopper having two legs. Particularly for small vials, the existing products tend to lift the stopper edges off the top face 320 of the vial 300 in line with the gaps between the legs. The additional force required to seat the stopper cap uniformly around the rim in this case is ameliorated by using three legs 230. When the stopper 200 is partially inserted into a vial 300, the separation and thickness of the legs 230 provide adequate leg stiffness to hold the stopper 200 up and out of the vial 300 while a vacuum is achieved in the vacuum suctioning operation (not shown).

[058] The separation of the legs 230 at the inner diameter is about 1.4 mm, and the separation of the legs 230 at the outer diameter of the legs 230 is about 2.4 mm. Radially speaking, each leg 230 has a thickness of about 2.45 mm along the length of the legs 230.

[059] The taper in the throat 310 of the vial 300 tends to cooperate with the side forces of the legs 230 of the shaft 220 to effectively resist insertion of the stopper 200 and to push the shaft 220 out of the vial 300. If the vacuum operation machinery (not shown) does not provide enough force to fully insert all the stoppers 200 into the vials 300 during the shelf closing operation, this can be alleviated by the stoppers 200 typically being lubricated with a coat of silicone oil during manufacture. Although this facilitates insertion, it also reduces holding friction that is meant to keep the stopper 200 inserted when the shelves open at the completion of the stopper insertion cycle. The side forces of the legs 230 on the tapered throat 310 of the vial 300 can cause the stopper 200 to lift out of the vial 300 at the end of the stopper insertion cycle. To avoid this issue, the length of the shaft 220 is increased so that the taper in the throat 310 does not occur at the end of the legs 230. The legs 230 have a length such that when the stopper 200 is fully inserted into the vial 300, the legs 230 sit past the tapered section of the throat 310, thereby providing a secure seating of the stopper 200 in the vial 300.

[060] The lower ring 240 can be positioned about 7.15 mm from the lower face 212 of the cap 210 such that when the stopper 200 is partially inserted into the vial 300, the lower ring

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240 is disposed beyond the neck 330 inside the vial 300, thereby positioning the stopper 200 partially inside the vial 300 and allowing air to escape the vial 300 through the passageways defined between each of the legs 230 during the vacuum process, while still being securely partially positioned within the vial.

[061] In an embodiment, the stopper 300 is configured to be positioned into sealing engagement with the vial 300 after air is removed from the vial 300 and possibly replaced with an injected gas. Subsequently, the stopper 200 is further inserted into the vial 300 so that the shaft 220 is moved into the throat 310 of the vial 300 and the sealing means 240 of the shaft 220 engages an inner surface of the neck 330 of the vial 300 to maintain a vacuum or gas in the vial 300.

[062] The stopper 200 according to embodiments of the present invention can overcome the limitations of the prior art by modifications that allow better sealing without the need for a crimped-on aluminium cap over the stopper 200. Further adjustments to the design promote robust manufacturing processes and compensate for variations in stopper-vial height.

[063] The features that can provide an improved stopper 200 include some of:

(1) an upper ring 240 on the stopper shaft 220;

(2) a thicker cap 210 of the stopper 200;

(3) three legs 230 instead of two legs or one leg;

(4) lengthening of the stopper shaft 220.

[064] It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

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Item List

200 - Stopper

210 - Cap of stopper 200

211 - Upper surface of cap 210

212 - Lower surface of cap 210

220 - Shaft of stopper 200

230 - Leg of stopper 200

240 - upper ring (sealing means) of stopper 200

250 - Lower ring of stopper 200

300 - Exemplary vial

310 - Throat of vial 300

320 - Top face of vial 300

330 - Neck of vial 300

Claims

The claims defining the invention are as follows:

1. A stopper configured to be inserted into and seal a vial having a top face, an opening, and a neck, the stopper comprising:

a cap having an upper surface and a lower surface;

a shaft protruding from the lower surface of the cap and configured to be inserted into the opening of the vial;

three legs extending from the shaft, each leg having a protrusion; and a sealing means extending around and protruding from the shaft, wherein:

the protrusions secure the stopper in the vial when the protrusions are disposed past the neck inside the vial; and the sealing means is configured to engage and create a seal with an inner surface of the neck when the shaft is inserted into the opening of the vial.
2. A stopper for maintaining a vacuum or gas seal of a vial having a top face, an opening, and a neck, the stopper comprising:

a cap having an upper surface and a lower surface;

a shaft extending longitudinally from the cap configured for insertion into the opening of the vial;

three legs equispaced around the shaft, the three legs configured to hold the stopper partially inserted in a vial to form passageways between the legs to allow movement of air out of the vial under vacuum and, in use, extend past the neck of the vial when the stopper is fully inserted in a vial;

a protrusion on each of the legs; and a sealing means protruding from the shaft proximal to the cap and above the legs to provide a seal in the throat of the vial as the lower surface of the cap is moved adjacent to the top face of the vial to maintain a vacuum or gas in the vial;

wherein the stopper is a unitary product formed from a flexible and resilient rubber material;

wherein the lower surface on the cap further provides a seal when the stopper is positioned in the vial and the cap abuts the top face of the vial; and wherein the stopper provides a seal and allows a vacuum or gas to be maintained in a vial without requiring a crimped-on metal cap to secure the stopper on the vial.
3. The stopper of claim 1 or 2, wherein each of the legs is deformable to facilitate insertion of the stopper into the vial.

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4. The stopper of any one of claims 1 to 3, wherein the cap is configured to be pierceable by a needle.
5. A method of sealing a vial having a top face, an opening, and a neck, the method comprising the steps of:

inserting the legs of a stopper according to any one of claims 1 to 4 into the opening of the vial such that each of the protrusions are disposed past the neck inside the vial to form a passageway to the inside of the vial between each of the legs;

removing a gas from the inside of the vial through one or more of the passageways; and inserting the shaft into the opening such that the sealing means engages and creates a seal with an inner surface of the neck of the vial.