Patent Publication Number: US-2019175447-A1

Title: Vial assembly with luer fitting

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority benefit of U.S. Provisional Application No. 62/375,394, filed Aug. 15, 2016, which is hereby incorporated by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to vials with a luer fitting for needless interface with a syringe. 
     BACKGROUND OF THE INVENTION 
     Medications are commonly withdrawn from medication vials using a syringe with a needle attached to the end of the needle. The needle pierces a rubber septum on the vial cap and is pushed to the liquid medication. Once the open end of the needle is submerged in the liquid medication, the medication is withdrawn by pulling a syringe plunger. 
     Use of syringes with needles for withdrawing medications from medication vials poses considerable downside risk. Healthcare workers risk injury or infection when working with sharps, including needles. Additionally, puncture of a rubber septum to access the vial contents can often cause fragments from the septum to break off and contaminate the medication. The contaminating particles, even if sterile, risk injury to a patient, particularly in ophthalmic applications. 
     Additionally, many medications are stabilized in a solid form, such as by lyophilizing a liquid medication. Adding lyophilized medications to a vial is often not practical, as it is difficult to aseptically transfer solid materials into a vial because many medications are sterilized by filtering a liquid formulation. However, aseptically lyophilizing the medication once it is dispensed in a vial is also challenging, as it often requires the open vial to be exposed to the ambient environment before attaching a vial cap, thereby risking contamination. 
     SUMMARY OF THE INVENTION 
     In one aspect of the present invention, there is provided a vial assembly comprising: a vial comprising a vial body and a vial neck, the vial neck having a syringe interface; and a vial cap having a central opening including a threaded segment that engages the syringe interface and a plug, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the vial cap. In some embodiments, the vial cap and the plug are coextruded. In some embodiments, the vial cap further including a rim, the upper portion of the plug including a top portion defining a restraint coupled to a reduced diameter region defining an annulus, wherein the rim of the vial cap extends into the annulus to hold the plug in place. In some embodiments, the plug further includes a central body with a diameter wider than the lower stopper portion. In some embodiments, the central body of the plug comprises a plurality of lateral compression ridges. In some embodiments, the restraint comprises a domed surface. In some embodiments, the restraint comprises a beveled rim. In some embodiments, the rim that extends into the annulus of the plug comprises an angled inner surface. In some embodiments, the rim that extends into the annulus of the plug is formed by an aperture on a top surface of the vial cap. In some embodiments, the rim that extends into the annulus of the plug protrudes into the central opening of the vial cap. 
     In another aspect, there is provided a vial assembly comprising: a vial comprising a vial body and a vial neck, the vial neck having a syringe interface; and a vial cap comprising a first component and a second component, said first component having an internal threaded segment that engages the syringe interface and an outer surface comprising a plurality of longitudinally extending ribs separated by a plurality of longitudinally extending channels, said second component including a plurality of longitudinally extending prongs that engage with a surface in the channels on the outer surface of the first component, said second component further including a central opening formed by the plurality of longitudinally extending prongs, and a plug disposed in the central opening, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the second component. In some embodiments, the second component and the plug are coextruded. In some embodiments, the second component further includes a rim, wherein the upper portion of the plug includes a top portion defining a restraint coupled to a reduced diameter region defining an annulus, and wherein the rim of the second component extends into the annulus to hold the plug in place. In some embodiments, the plug further includes a central body with a diameter wider than the lower stopper portion. In some embodiments, the central body of the plug comprises a plurality of lateral compression ridges. In some embodiments, the restraint comprises a domed surface. In some embodiments, the restraint comprises a beveled rim. In some embodiments, the rim that extends into the annulus of the plug comprises an angled inner surface. In some embodiments, the rim that extends into the annulus of the plug is formed by an aperture on a top surface of the vial cap. In some embodiments, the rim that extends into the annulus of the plug protrudes into the central opening of the vial cap. In some embodiments, at least one of the prongs in the plurality of longitudinally extending prongs comprises an anchor that engages a counter-anchor disposed in a channel in the plurality of longitudinally extending channels. 
     In some embodiments, the vial neck is tapered. In some embodiments, the syringe interface is a second threaded segment on an outer surface of the vial neck. In some embodiments, the syringe interface is a female luer. 
     In some embodiments, the stopper portion of the plug forms a seal with the inner surface of the vial neck. 
     In some embodiments, the vial assembly comprises a tamper-evident band. In some embodiments, the vial comprises an annular lip disposed on the outer surface of the vial neck; the tamper-evident band is attached to the vial cap; and the annular lip disposed on the outer surface of the vial neck secures the tamper-evident band to the vial. 
     In some embodiments, the vial body has an open base. In some embodiments, the vial body includes a base that is sealed with a thermoformed plastic or foil. 
     In another aspect, there is provided a vial assembly comprising: a vial having a vial body and a vial neck; an adapter having a top portion having a syringe interface, a bottom portion having a vial neck fitting attached to the vial neck, and a channel fluidly connecting the syringe interface to the vial neck; a gasket disposed between the vial neck and the adapter; and a vial cap having a central opening including a threaded segment that engages the syringe interface and a plug, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the vial cap. In some embodiments, the vial cap and the plug are coextruded. In some embodiments, the vial cap further includes a rim, the upper portion of the plug includes a top portion defining a restraint coupled to a reduced diameter region defining an annulus, and the rim of the vial cap extends into the annulus to hold the plug in place. In some embodiments, the plug further includes a central body with a diameter wider than the lower stopper portion. In some embodiments, the central body of the plug comprises a plurality of lateral compression ridges. In some embodiments, the restraint comprises a domed surface. In some embodiments, the restraint comprises a beveled rim. In some embodiments, the rim that extends into the annulus of the plug comprises an angled inner surface. In some embodiments, the rim that extends into the annulus of the plug is formed by an aperture on a top surface of the vial cap. In some embodiments, the rim that extends into the annulus of the plug protrudes into the central opening of the vial cap. 
     In some embodiments, the vial cap comprises a skirt that surrounds a portion of the vial neck fitting of the adapter. In some embodiments, the vial cap comprises an outer surface comprising a plurality of longitudinally extending ribs. 
     In some embodiments, the syringe interface is a tapered conduit. In some embodiments, the syringe interface is a second threaded segment on an outer surface of a conduit. In some embodiments, the syringe interface is a female luer. In some embodiments, the vial neck fitting comprises a plurality of prongs that comprise an anchor that engages an annular lip on the vial neck. 
     In some embodiments, the vial assembly comprises a tamper-evident band. In some embodiments, the vial cap comprises a skirt that surrounds a portion of the vial neck fitting of the adapter; the tamper-evident band is attached to the skirt; and the adapter secures the tamper-evident band to the vial. 
     In another aspect, there is provided a vial assembly comprising: a vial having a vial body and a vial neck, the vial neck comprising an inner surface and an outer surface, the outer surface comprising an annular lip; and a vial cap having: a stopper having a top portion and a bottom portion, the top portion comprising a longitudinal aperture, and the bottom portion that fits into the vial neck; a conduit having a syringe interface at a first end and a barb at a second end, the second end fitting through the aperture in the stopper, and said barb engaging an underside of the top portion of the stopper; and an end cap having a central opening including a threaded segment that engages the syringe interface and a plug disposed in the central opening, said plug having a lower stopper portion that fits within the syringe interface of the conduit and an upper portion that attaches to an upper portion of the end cap. In some embodiments, the end cap and the plug are coextruded. In some embodiments, the end cap further includes a rim, wherein the upper portion of the plug includes a top portion defining a restraint coupled to a reduced diameter region defining an annulus, and wherein the rim of the end cap extends into the annulus to hold the plug in place. In some embodiments, the plug further includes a central body with a diameter wider than the lower stopper portion. In some embodiments, the central body of the plug comprises a plurality of lateral compression ridges. In some embodiments, the restraint comprises a domed surface. In some embodiments, the restraint comprises a beveled rim. In some embodiments, the rim that extends into the annulus of the plug comprises an angled inner surface. In some embodiments, the rim that extends into the annulus of the plug is formed by an aperture on a top surface of the vial cap. In some embodiments, the rim that extends into the annulus of the plug protrudes into the central opening of the vial cap. 
     In some embodiments, the syringe interface is tapered. In some embodiments, the syringe interface is a second threaded segment on an outer surface of the syringe interface. In some embodiments, he syringe interface is a female luer. 
     In some embodiments, the stopper comprises a raised annular ridge around the aperture at the top of the stopper; and the end cap comprises a skirt that fits around the raised annular ridge. 
     In some embodiments, the stopper comprises an annular lip that sits on the annular lip disposed on an outer surface of the vial neck. In some embodiments, the vial assembly further comprises a ring that secures the stopper to the vial neck. 
     In some embodiments, the vial assembly further comprises a tamper-evident band. In some embodiments, the end cap comprises a tamper-evident band that covers a portion of the annular lip, and the ring secures the temper-evident band and the stopper to the vial neck. 
     In some embodiments, the bottom portion of the stopper comprises at least one truncated segment. 
     In another aspect, there is provided a method of filing a vial assembly comprising: dispensing a liquid comprising the substance into a vial assembly comprising: a vial having a vial body and a vial neck, the vial neck having a syringe interface; and a vial cap having a central opening including a threaded segment that engages the syringe interface and a plug, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the vial cap; wherein the liquid is dispensed through an open base of the vial body; and sealing the base of the vial body after the liquid has been dispensed. In some embodiments, the vial cap further includes a rim, the upper portion of the plug includes a top portion defining a restraint coupled to a reduced diameter region defining an annulus, and the rim of the vial cap extends into the annulus to hold the plug in place. In some embodiments, the plug further includes a central body with a diameter wider than the lower stopper portion. In some embodiments, method further includes the step of attaching the plug to the vial cap. In some embodiments, he vial cap and the plug are coextruded. 
     In some embodiments, the method further includes the step of attaching the vial cap to the vial neck. 
     In some embodiments, the method further includes the step of lyophilizing the liquid prior to sealing the base of the vial body. 
     In some embodiments, the method further includes the steps of: detaching the vial cap from the vial neck, attaching a syringe to the vial neck, and drawing the liquid into the syringe. 
     In some embodiments, the method further includes the steps of: detaching the vial cap from the vial neck, attaching a syringe to the vial neck, dispensing a second liquid into the vial after attaching the syringe to the vial neck, drawing the liquid into the syringe. 
     In some embodiments, the base of the vial body is sealed with a thermoformed plastic or foil. 
     In some embodiments, the vial neck is tapered. In some embodiments, the syringe interface is a second threaded segment on an outer surface of the vial neck. In some embodiments, the syringe interface is a female luer. 
     In another aspect there is provided a method of filling a vial assembly comprising: dispensing a liquid into a vial comprising a vial body and a vial neck, the vial neck having a syringe interface; attaching a first component of a vial cap to the vial neck, said first component having an internal threaded segment that engages the syringe interface and an outer surface comprising a plurality of longitudinally extending ribs separated by a plurality of longitudinally extending channels; and sealing the vial by attaching a second component of the vial cap to the first component, said second component including a plurality of longitudinally extending prongs that engage with a surface in the channels on the outer surface of the first component, said second component further including a central opening formed by the plurality of longitudinally extending prongs, and a plug disposed in the central opening, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the second component. In some embodiments, the second component further includes a rim, wherein the upper portion of the plug includes a top portion defining a restraint coupled to a reduced diameter region defining an annulus, and the rim of the vial cap extends into the annulus to hold the plug in place. In some embodiments, the plug further includes a central body with a diameter wider than the lower stopper portion. In some embodiments, further includes the step of attaching the plug to the second component of the vial cap. In some embodiments, the second component and the plug are coextruded. 
     In some embodiments, sealing the vial includes engaging an anchor on at least one of the prongs in the plurality of longitudinally disposed prongs with a counter-anchor disposed in a channel in the plurality of longitudinally disposed channels. 
     In some embodiments, the first component of the vial cap is attached to the vial neck prior to dispensing the liquid into the vial. In some embodiments, the liquid is dispensed into the vial prior to attaching the first component of the vial cap to the vial neck. 
     In some embodiments, the method further includes the steps of: detaching the vial cap from the vial neck, attaching a syringe to the vial neck, and drawing the liquid into the syringe. 
     In some embodiments, the method further includes the step of lyophilizing the liquid prior to sealing the vial. 
     In some embodiments, the method further includes partially engaging the second component with the first component without forming a seal prior to lyophilizing the liquid. 
     In some embodiments, the method further includes the steps of: detaching the vial cap from the vial neck, attaching a syringe to the vial neck, dispensing a second liquid into the vial after attaching the syringe to the vial neck, and drawing the liquid into the syringe. 
     In some embodiments, the method further includes the syringe interface is tapered. In some embodiments, the method further includes the syringe interface is a second threaded segment on an outer surface of the vial neck. In some embodiments, the method further includes the syringe interface is a female luer. 
     In another aspect, there is provided a method of filling a vial assembly comprising; dispensing a liquid into a vial comprising a vial body and a vial neck; attaching an adapter to the vial neck, said adapter comprising a top portion having a syringe interface, a bottom portion having a vial neck fitting, a gasket fitting within the vial neck fitting, and a longitudinally extending channel fluidly connecting the syringe interface to the vial neck; and sealing the vial by attaching a vial cap to the adapter, said vial cap having a central opening including a threaded segment that engages the syringe interface and a plug, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the vial cap. In some embodiments, the method further includes fitting the gasket along an inner edge of the vial neck fitting prior to attaching the adapter to the vial neck. In some embodiments, the method further includes attaching the vial cap to the adapter prior to attaching the adapter to the vial neck. 
     In some embodiments, the vial cap further includes a rim, the upper portion of the plug includes a top portion defining a restraint coupled to a reduced diameter region defining an annulus, and the rim of the vial cap extends into the annulus to hold the plug in place. In some embodiments, the plug further includes a central body with a diameter wider than the lower stopper portion. 
     In some embodiments, the method further includes the step of attaching the plug to the vial cap. 
     In some embodiments, the vial cap and the plug are coextruded. 
     In some embodiments, the liquid is dispensed into the vial after attaching the adapter to the vial neck. 
     In some embodiments, the method further includes the step of lyophilizing the liquid. In some embodiments, the method includes the steps of: placing the vial cap on the adapter in an unsealed configuration prior to lyophilizing the liquid; and sealing the vial by tightening the vial cap after lyophilizing the liquid. 
     In some embodiments, the method further includes the steps of: detaching the vial cap from the vial neck, attaching a syringe to the vial neck, and drawing the liquid into the syringe. 
     In some embodiments, the method further includes the steps of: detaching the vial cap from the vial neck, attaching a syringe to the vial neck, dispensing a second liquid into the vial after attaching the syringe to the vial neck, and drawing the liquid into the syringe. 
     In some embodiments, the syringe interface is tapered. In some embodiments, the syringe interface is a second threaded segment on an outer surface of the vial neck. In some embodiments, the syringe interface is a female luer. 
     In another aspect, there is provided a method of filling a vial assembly comprising: dispensing a liquid into a vial comprising a vial body and a vial neck the vial neck; and sealing the vial by attaching a vial cap to the vial neck, the vial cap having: a stopper having a top portion and a bottom portion, the top portion comprising a longitudinal aperture, and the bottom portion that fits into the vial neck; a conduit having a syringe interface at a first end and a barb at a second end, the second end fitting through the aperture in the stopper, and said barb engaging an underside of top portion of the stopper; and an end cap having a central opening including a threaded segment that engages the syringe interface and a plug disposed in the central opening, said plug having a lower stopper portion that fits within the syringe interface of the conduit and an upper portion that attaches to an upper portion of the end cap. In some embodiments, the end cap and the plug are coextruded. In some embodiments, the end cap includes a rim, the upper portion of the plug includes a top portion defining a restraint coupled to a reduced diameter region defining an annulus, and the rim of the end cap extends into the annulus to hold the plug in place. In some embodiments, the plug further includes a central body with a diameter wider than the lower stopper portion. 
     In some embodiments, the method further includes the step of attaching the conduit to the end cap. In some embodiments, the method further includes the step of attaching the conduit to the stopper. 
     In some embodiments, the vial cap is pre-assembled. 
     In some embodiments, the stopper includes an annular lip that sits on an annular lip disposed on an outer surface of the vial neck. In some embodiments, the method further includes the step of securing the stopper to the vial neck by attaching a ring around the annular lip of the stopper and the annular lip of the vial neck. 
     In some embodiments, the method further includes the step of lyophilizing the liquid prior to sealing the vial. In some embodiments, the method further includes the step of partially inserting the bottom portion of the stopper into the vial neck prior to lyophilizing the liquid. In some embodiments, the method includes the step of fully inserting the bottom portion of the stopper into the vial neck after lyophilizing the liquid. 
     In some embodiments, the method includes the steps of: detaching the vial cap from the vial neck, attaching a syringe to the vial neck, and drawing the liquid into the syringe. 
     In some embodiments, the method includes the steps of: detaching the vial cap from the vial neck, attaching a syringe to the vial neck, dispensing a second liquid into the vial after attaching the syringe to the vial neck, and drawing the liquid into the syringe. 
     In some embodiments, the syringe interface is a second threaded segment on an outer surface of the vial neck. In some embodiments, the syringe interface is a female luer. 
     In another aspect, there is provided a method of filling a syringe, comprising: detaching a vial cap from a vial, the vial having a vial body and a vial neck, the vial neck having a syringe interface; and the vial cap having a central opening including a threaded segment that engages the syringe interface and a plug, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the vial cap; attaching a syringe to the vial neck; and drawing a liquid contained within the vial into the syringe. In some embodiments, the vial cap and the plug are coextruded. In some embodiments, the vial cap includes a rim, the upper portion of the plug includes a top portion defining a restraint coupled to a reduced diameter region defining an annulus, and the rim of the vial cap extends into the annulus to hold the plug in place. In some embodiments, the plug further includes a central body with a diameter wider than the lower stopper portion. 
     In another aspect, there is provided a method of filling a syringe, comprising: detaching a vial cap from a vial, the vial having a vial body and a vial neck, the vial neck having a syringe interface; and the vial cap comprising a first component and a second component, said first component having an internal threaded segment that engages the syringe interface and an outer surface comprising a plurality of longitudinally extending ribs separated by a plurality of longitudinally extending channels, said second component including a plurality of longitudinally extending prongs that engage with a surface in the channels on the outer surface of the first component, said second component further including a central opening formed by the plurality of longitudinally extending prongs and a plug disposed in the central opening, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the second component; attaching a syringe to the syringe interface of the vial neck; and drawing a liquid contained within the vial into the syringe. In some embodiments, the second component and the plug are coextruded. In some embodiments, the second component further includes a rim, the upper portion of the plug includes a top portion defining a restraint coupled to a reduced diameter region defining an annulus, and the rim of the second component extends into the annulus to hold the plug in place. In some embodiments, he plug further includes a central body with a diameter wider than the lower stopper portion. 
     In some embodiments, at least one of the prongs in the plurality of longitudinally extending prongs comprises an anchor that engages a counter-anchor disposed in a channel in the plurality of longitudinally extending channels. 
     In some embodiments, the vial neck is tapered. In some embodiments, the syringe interface is a second threaded segment on an outer surface of the vial neck. In some embodiments, the syringe interface is a female luer. 
     In some embodiments, the step of detaching the vial cap includes unscrewing the vial cap. 
     In some embodiments, the syringe comprises a male luer lock that interfaces with the syringe interface. 
     In some embodiments, the method further includes a step of forming the liquid by adding a solution to the vial, and dissolving or suspending a lyophilized powder contained within the vial. 
     In some embodiments, the step of detaching the vial cap includes severing a tamper-evident band from the vial cap. 
     In another aspect, there is provided a method of filling a syringe, comprising: detaching a vial cap from a vial assembly comprising: a vial comprising a vial body and a vial neck; an adapter comprising a top portion having a syringe interface, a bottom portion having a vial neck fitting attached to the vial neck, and a channel fluidly connecting the syringe interface to the vial neck; a gasket disposed between the vial neck and the adapter; and the vial cap; said vial cap having a central opening including a threaded segment that engages the syringe interface and a plug, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the vial cap; attaching a syringe to the syringe interface; and drawing a liquid contained within the vial into the syringe. In some embodiments, the end cap and the plug are coextruded. In some embodiments, the vial cap further includes a rim, the upper portion of the plug includes a top portion defining a restraint coupled to a reduced diameter region defining an annulus, and the rim of the vial cap extends into the annulus to hold the plug in place. In some embodiments, the plug further includes a central body with a diameter wider than the lower stopper portion. 
     In some embodiments, the syringe interface is tapered. In some embodiments, the syringe interface is a second threaded segment on an outer surface of a conduit. In some embodiments, the syringe interface is a female luer. 
     In some embodiments, the syringe comprises a male luer lock that interfaces with the syringe interface. 
     In some embodiments, the method further includes a step of forming the liquid by adding a solution to the vial, and dissolving or suspending a lyophilized powder contained within the vial. In some embodiments, the step of detaching the vial cap includes unscrewing the vial cap. In some embodiments, the step of detaching the vial cap includes severing a tamper-evident band from the vial cap. 
     In another aspect, there is provided a method of filling a syringe, comprising: detaching an end cap from a vial assembly comprising: a vial having a vial body and a vial neck, the vial neck having an inner surface and an outer surface, the outer surface having an annular lip; and a vial cap having: a stopper having a top portion and a bottom portion, the top portion comprising a longitudinal aperture, and the bottom portion that fits into the vial neck; a conduit having a syringe interface at a first end and a barb at a second end, the second end fitting through the aperture in the stopper, and said barb engaging an underside of top portion of the stopper; and the end cap; said end cap having a central opening including a threaded segment that engages the syringe interface and a plug disposed in the central opening, said plug having a lower stopper portion that fits within the syringe interface of the conduit and an upper portion that attaches to an upper portion of the end cap; attaching a syringe to the syringe interface; and drawing a liquid contained within the vial into the syringe. In some embodiments, the end cap and the plug are coextruded. In some embodiments, the end cap includes a rim, wherein the upper portion of the plug includes a top portion defining a restraint coupled to a reduced diameter region defining an annulus, and the rim of the end cap extends into the annulus to hold the plug in place. In some embodiments, the plug further includes a central body with a diameter wider than the lower stopper portion. 
     In some embodiments, the syringe interface is tapered. In some embodiments, the syringe interface is a second threaded segment on an outer surface of the conduit. In some embodiments, the syringe interface is a female luer. In some embodiments, the syringe comprises a male luer lock that interfaces with the syringe interface. 
     In some embodiments, the method further includes a step of forming the liquid by adding a solution to the vial, and dissolving or suspending a lyophilized powder contained within the vial. 
     In some embodiments, the step of detaching the vial cap includes unscrewing the end cap. In some embodiments, the step of detaching the vial cap includes severing a tamper-evident band from the vial cap. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  illustrates an exemplary vial assembly comprising a vial and a vial cap next to a vial without the vial cap. 
         FIG. 1B  illustrates a cross-sectional view of the vial assembly illustrated in  FIG. 1A . 
         FIG. 1C  illustrates a close-up cross-sectional view of the vial cap with a plug illustrated in  FIG. 1B . The plug includes a stopper portion, a central body, a restraint, and a reduced diameter region defining an annulus between the central body and the restraint. 
         FIG. 1D  illustrates a close-up cross-sectional view of the vial cap with a plug illustrated in  FIG. 1B  with a tamper-evident band. 
         FIG. 2  illustrates one method of filling a vial assembly with a liquid. Optionally, the liquid is lyophilized. In the illustrated embodiment, the vial body includes an open base through which the liquid can be dispensed. Once the liquid is dispensed in the vial, the liquid can be optionally lyophilized, and then the vial is sealed. 
         FIG. 3A  illustrates another exemplary vial assembly comprising a vial and a vial cap next to a vial without the vial cap. The vial cap includes a first component and a second component. 
         FIG. 3B  illustrates the first component of an exemplary vial cap attached to a vial, along with a close-up cross-sectional view of the first component attached to the vial. 
         FIG. 3C  illustrates the second component of an exemplary vial cap attached to the first component of the vial cap in an unsealed configuration. The second component sits on top of the first component. Also illustrated in  FIG. 3C  is a close-up cross-sectional view of the vial cap in the unsealed configuration. 
         FIG. 3D  illustrates a cross-sectional view of an exemplary vial cap having a first component and a second component in a sealed configuration. 
         FIG. 3E  illustrates a cross-sectional view of an exemplary vial cap having a first component and a second component in a sealed configuration with a tamper-evident band. 
         FIG. 4  illustrates one embodiment of a method for filling a vial assembly comprising a vial cap with a first component and a second component. 
         FIG. 5A  illustrates an exemplary embodiment of a vial assembly in a fully assembled, partially assembled, and an unassembled configuration, the vial assembly comprising a vial, an adapter, and a vial cap. A gasket can be fits into the adapter. A plug fits into the vial cap. 
         FIG. 5B  illustrates a close-up cross-sectional view of an adapter and a vial cap assembled on a vial in an exemplary vial assembly. 
         FIG. 5C  illustrates a side-by-side view of the sealed and unsealed configurations of a vial cap in an exemplary vial assembly having a vial, an adapter, and a vial cap having a plug. 
         FIG. 5D  illustrates a cross-sectional view of the sealed configuration of a vial cap in an exemplary vial assembly having a vial, an adapter, a vial cap having a plug, and a tamper-evident band. 
         FIG. 6A  illustrates an exemplary embodiment of a vial assembly comprising a vial and a vial cap comprising a stopper, a conduit, and an end cap, along with a cross-sectional view of the vial assembly. 
         FIG. 6B  illustrates a close-up view of vial cap components (including a stopper, a conduit, and an end cap), the vial cap with the components pre-assembled, and a cross-sectional view of each for an exemplary vial assembly. 
         FIG. 6C  illustrates an exemplary vial assembly with a vial cap comprising a stopper in an unsealed configuration. In the unsealed configuration for this exemplary embodiment, the bottom portion of the stopper is partially inserted into a vial neck, and a gap exists between a truncated segment of the bottom portion of the stopper and the end of the vial neck. 
         FIG. 6D  illustrates a cross-sectional view of an exemplary vial assembly in a sealed configuration and an unsealed configuration. 
         FIG. 6E  illustrates a cross-sectional view of an exemplary vial assembly in a sealed configuration with a tamper-evident band. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Provided herein are vial assemblies for needless interface of a syringe with a vial. The described assemblies allow for the transfer of liquids from a vial to a syringe without needing to pierce a septum in a vial cap using a needle. Liquid or solid substances (such as medications) can be contained within the vials that are sealed with the described vial caps. The vial cap (or a portion of the vial cap) can be detached from the vial assemblies to reveal a syringe interface. A syringe, which may include a male luer (such as a male luer lock or male slip tip) can attach to the syringe interface. The syringe is thereby fluidly connected to the substance contained within the vial. Optionally, the syringe can have a liquid that is dispensed into the vial after attaching to the syringe interface. For example, if the substance contained within the medication vial is a solid, the syringe can dispense a liquid to dissolve or suspend the substance. The syringe can also be used to withdraw the liquid contained in the vial once the syringe is attached to the syringe interface. Thus, the vial assemblies allow for a needless interface with a syringe, as well as the needless withdrawal of a liquid contained within a vial. 
     Additionally, the described vial assemblies allow for liquids to be lyophilized once dispensed in the vials, and for reconstitution of lyophilized products contained within the vials. Many medications are more stable in a lyophilized form. However, it is often difficult to aseptically manufacture a sealed vial containing a lyophilized substance. For example, adding a liquid to a vial, lyophilizing the liquid, and then attaching the vial cap leaves the vial neck uncovered and the medication exposed during the lyophilization process. This exposure can result in contamination. In some embodiments, the vial assemblies described herein not only allow for needless interface with syringes, but also allow for aseptic lyophilization of liquids contained within the vial. 
     The vial assemblies and methods described herein allow for needless filling and withdrawal of liquids, such as liquid medications. The vial assemblies include a vial and a cap. The vial may be any medicine vial, such as a 1 mL, 2 mL, 5 mL, 10 mL, 15 mL, 20 mL, 25 mL, 30 mL or any other size vial. The vial may be made from glass, plastic, or any other suitable material. The vial includes a vial neck and a vial body. In some embodiments, the vial neck includes a syringe interface, such as a female luer or an outer surface with a threaded segment. In some embodiments, the vial neck may comprise an annular lip, which may be disposed at the top of the vial neck (i.e., proximal to the vial opening), the bottom of the vial neck (i.e., proximal to the vial body), or both. 
     In any of the methods described herein, the vial assembly can be filled with a liquid via the base of the vial body or via the vial neck. For example, in some embodiments, the vial cap is attached to the vial in a sealed configuration and the vial body has an open base. The vial can be inverted (that is, the open base can be facing upward) and the liquid dispensed in the vial. The vial vase can be sealed, for example by sealing the open base with a foil or a thermoformed plastic. 
     In any of the methods described herein, the liquid dispensed in the vial can be lyophilized Lyophilizing can be performed, for example, by freezing the liquid (for example, by cooling the liquid do about 0° C. or less, about −20° C. or less, −40° C. or less, −60° C. or less, or −80° C. or less) and by exerting a vacuum (such as about 800 mTorr or less about 600 mTorr or less, about 500 mTorr or less, about 400 mTorr or less, about 300 mTorr or less, about 200 mTorr or less, or about 100 mTorr or less). In some embodiments, the vial cap is attached to the vial neck in an unsealed configuration during lyophilization. 
     The vial caps and vial cap components (such as an adapter, a stopper, a plug, or an end cap, a gasket, etc.) may be metal, rubber, or a polymer, or any combination of such materials. The plugs are attached to the vial cap (or vial cap component or end cap), and may be coextruded with the vial cap (or vial cap component or end cap) or the plug may be a separate component that is attached to the vial cap (or vial cap component or end cap), for example, by engaging a rim. In some embodiments, the plug is elastomeric. The plug may be rubber, an elastomeric polymer, or any other suitable material. 
     In some embodiments, the vial assembly comprises a vial comprising a vial body and a vial neck, the vial neck having a syringe interface; and a vial cap having a central opening including a threaded segment that engages the syringe interface and a plug, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the vial cap. In some embodiments, the vial neck has a tapered inner surface. In some embodiments, the syringe interface is a female luer. In some embodiments, the syringe interface is a second threaded segment on the outer surface of the vial neck. In some embodiments, the vial assembly comprises a tamper-evident band. 
     In some embodiments, the vial assembly comprises a vial comprising a vial body and a vial neck, the vial neck having a syringe interface; and a vial cap having a central opening including a threaded segment that engages the syringe interface and a coextruded plug disposed within the central opening, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the vial cap. In some embodiments, the vial neck has a tapered inner surface. In some embodiments, the syringe interface is a female luer. In some embodiments, the syringe interface is a second threaded segment on the outer surface of the vial neck. In some embodiments, the vial assembly comprises a tamper-evident band. 
     In some embodiments, the vial assembly comprises a vial comprising a vial body and a vial neck, the vial neck having a syringe interface; and a vial cap having a central opening including a threaded segment that engages the syringe interface and a rim, said vial cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the vial neck, and an upper portion including a top portion defining a restraint coupled to a reduced diameter region defining an annulus, wherein the rim of the vial cap extends into the annulus to hold the plug in place. In some embodiments, the vial neck has a tapered inner surface. In some embodiments, the syringe interface is a female luer. In some embodiments, the syringe interface is a second threaded segment on the outer surface of the vial neck. In some embodiments, the vial assembly comprises a tamper-evident band. 
     In some embodiments, the vial assembly comprises a vial comprising a vial body and a vial neck, the vial neck having a syringe interface; and a vial cap having a central opening including a threaded segment that engages the syringe interface and a rim, said vial cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the vial neck, a central body with a diameter wider than the lower stopper portion (the central body optionally including a plurality of compression ridges), and an upper portion including a top portion defining a restraint (which can optionally have a domed surface or a beveled rim) coupled to a reduced diameter region defining an annulus, wherein the rim of the vial cap extends into the annulus to hold the plug in place. In some embodiments, the vial neck has a tapered inner surface. In some embodiments, the syringe interface is a female luer. In some embodiments, the syringe interface is a second threaded segment on the outer surface of the vial neck. In some embodiments, the vial assembly comprises a tamper-evident band. 
       FIG. 1A  illustrates an exemplary vial assembly comprising a vial  100  and a vial cap  102  next to a vial  100  without the vial cap.  FIG. 1B  illustrates a cross-sectional view of the same vial assembly illustrated in  FIG. 1A . The vial includes a vial body  104  and a vial neck  106 . The vial body  104  can contain a liquid or a powder (which can be, for example, formed by lyophilizing a liquid). The vial neck  106  includes a syringe interface configured to engage a threaded segment  108  within a central opening of the vial cap  102 . For example, in some embodiments the vial neck  106  has an outer surface that has a threaded segment  110 , as illustrated in  FIG. 1A . In some embodiments, the vial neck  106  includes a female luer lock. The threaded vial neck or female luer lock can interface with a male luer lock or slip tip (for example, on a syringe). In some embodiments, the inner portion of the vial neck  106  is tapered (that is, a bottom inner diameter proximal to the vial body is smaller than an upper inner diameter proximal to a vial opening). The vial can be, for example, a medication bottle, and can be glass, a polymer, or any other suitable material. 
     The vial cap  102  includes a central opening having a threaded segment  108  within the central opening of the vial cap  102 . The threaded segment  108  is located on the bottom portion of the vial cap  102 . The vial cap  102  further comprises a plug  112 , which attaches to the vial cap  102  at the top portion of the vial cap  102 . Optionally, the outer surface of the vial cap  102  comprises a plurality of longitudinally disposed ribs  113 , which can help provide traction when opening or closing the vial assembly. 
     Referring now to  FIG. 1C , which illustrates a close-up cross-sectional view of the vial cap, the plug comprises a stopper portion  114 , a central body  116 , a restraint  118 , and a reduced diameter region defining an annulus  120  between the central body  116  and the restraint  118 . The stopper portion  114  of the plug is disposed in the direction of the threaded segment  108  of the vial cap  102  and fits into the vial neck  106  to form a seal. In some embodiments, the stopper portion  114  is tapered (that is, a bottom diameter is smaller than an upper diameter). The central body  116  is wider than the stopper portion  114 , and can sit on the end of the vial neck  106  proximal to the vial opening. In some embodiments, the central body  116  comprises a plurality of lateral compression ridges disposed on its outer surface, which can aid in sealing the vial. The vial cap  102  comprises a rim  122  that extends into the annulus  120 . The rim  122  can be formed, for example, by an aperture in the vial cap  102 . The aperture can extend through the top of the vial cap  102 , or the aperture can be internal in the vial cap. In some embodiments, the rim  122  comprises a plurality of prongs. The restraint  118  locks the plug into the vial cap  102  once attached by extending over the rim  122  and holding the rim  122  in the annulus  120 . 
     The restraint  118  can be shaped to allow unidirectional movement, for example by having a narrower top and a wider base. For example, in some embodiments, the restraint is domed shaped. In some embodiments, the restraint  118  comprises a beveled rim  124  such that the top of the restraint is narrower than the base of the restraint. The rim  122  that extends into the annulus  120  can optionally comprise an angled edge  126 . For example, the rim  122  can comprise an angled edge  126  such that the bottom edge of the rim is shorter than the top edge. In some embodiments, the rim  122  comprises an angled edge  126  such that a top portion or a bottom portion of the rim is beveled. In the cap illustrated in  FIG. 1C , the bottom potion of the rim  122  is beveled, thereby forming the angled edge  126 . The angled edge  126  can be used alone or in combination with the restraint  118  shaped to allow unidirectional movement to facilitate attachment of the plug  112  into the vial cap  102 . 
     In some embodiments, the vial assembly comprises a tamper-evident band ( FIG. 1D ). For example, in some embodiments, the vial comprises an annular lip  128  disposed on the outer surface of the vial neck  106 . The annular lip  128  is disposed on the proximal end of the vial neck  106  (i.e., closer to the vial body than the vial opening). The tamper-evident band  130  is attached to the vial cap  102  and wraps below the annular lip on the vial neck  106 . For example, the tamper-evident band can be attached to the vial cap  102  by a perforated segment  132 . When the vial cap  102  is separated from the vial  100 , the annular lip  128  on the vial neck  106  retains the tamper-evident band  130  and the perforate segment  132  is torn, thereby separating the tamper-evident band  130  from the vial cap  102 . This separation indicates that the vial cap  102  has been opened. 
     The vial can be filled with a liquid (for example, a liquid medication) from either vial neck opening or from the base of the vial body. That is, in some embodiments, the vial body comprises an open base, which can be sealed after a liquid is dispensed in the vial (for example using a thermoformed plastic or foil). When dispensing liquid into the vial through the open base, the vial cap is attached to the vial prior to dispensing the liquid into the vial. When a liquid is dispensed into the vial through an opening in the vial neck, the vial cap is attached to the vial after dispensing the liquid into the vial. In some embodiments, the liquid is dispensed into the vial from the vial neck, and the vial cap is then attached to the vial neck. Optionally, the liquid is lyophilized prior to attaching the vial cap to the vial neck. 
     In some embodiments, a method of filling a vial assembly comprises dispensing a liquid into a vial assembly comprising a vial having a vial body and a vial neck, the vial neck having a syringe interface; and a vial cap having a central opening including a threaded segment that engages the syringe interface and a plug, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the vial cap; wherein the liquid is dispensed through an open base of the vial body; and sealing the base of the vial body after the liquid has been dispensed. In some embodiments, the vial neck has a tapered inner surface. In some embodiments, the syringe interface is a female luer. In some embodiments, the syringe interface is a second threaded segment on the outer surface of the vial neck. In some embodiments, the liquid is lyophilized prior to sealing the base of the vial body. In some embodiments, the method includes attaching the vial cap to the vial neck. 
     In some embodiments, a method of filling a vial assembly comprises dispensing a liquid into a vial assembly comprising a vial comprising a vial body and a vial neck, the vial neck having a syringe interface; and a vial cap having a central opening including a threaded segment that engages the syringe interface and a coextruded plug disposed with in the central opening, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the vial cap; wherein the liquid is dispensed through an open base of the vial body; and sealing the base of the vial body after the liquid has been dispensed. In some embodiments, the vial neck has a tapered inner surface. In some embodiments, the syringe interface is a female luer. In some embodiments, the syringe interface is a second threaded segment on the outer surface of the vial neck. In some embodiments, the liquid is lyophilized prior to sealing the base of the vial body. In some embodiments, the method includes attaching the vial cap to the vial neck. 
     In some embodiments, a method of filling a vial assembly comprises dispensing a liquid into a vial assembly comprising a vial having a vial body and a vial neck, the vial neck having a syringe interface; and a vial cap having a central opening including a threaded segment that engages the syringe interface and a rim, said vial cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the vial neck, and an upper portion including a top portion defining a restraint coupled to a reduced diameter region defining an annulus, wherein the rim of the vial cap extends into the annulus to hold the plug in place; wherein the liquid is dispensed through an open base of the vial body; and sealing the base of the vial body after the liquid has been dispensed. In some embodiments, the vial neck has a tapered inner surface. In some embodiments, the syringe interface is a female luer. In some embodiments, the syringe interface is a second threaded segment on the outer surface of the vial neck. In some embodiments, the liquid is lyophilized prior to sealing the base of the vial body. In some embodiments, the method includes attaching the vial cap to the vial neck. 
     In some embodiments, a method of filling a vial assembly comprises dispensing a liquid into a vial assembly comprising a vial having a vial body and a vial neck, the vial neck having a syringe interface; and a vial cap having a central opening including a threaded segment that engages the syringe interface and a rim, said vial cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the vial neck, a central body with a diameter wider than the lower stopper portion (the central body optionally including a plurality of compression ridges), and an upper portion including a top portion defining a restraint (which can have a domed surface or a beveled rim) coupled to a reduced diameter region defining an annulus, wherein the rim of the vial cap extends into the annulus to hold the plug in place; wherein the liquid is dispensed through an open base of the vial body; and sealing the base of the vial body after the liquid has been dispensed. In some embodiments, the vial neck has a tapered inner surface. In some embodiments, the syringe interface is a female luer. In some embodiments, the syringe interface is a second threaded segment on the outer surface of the vial neck. In some embodiments, the liquid is lyophilized prior to sealing the base of the vial body. In some embodiments, the method includes attaching the vial cap to the vial neck. 
       FIG. 2  illustrates one method of filling the vial assembly with a liquid, such as a medication. The vial assembly and components are illustrated in a cross-sectional view. The vial comprises a vial body  202 , a vial neck  204 , and an open base  206 . The vial neck  204  includes a syringe interface configured to engage a threaded segment  208  of the vial cap  210 . For example, in some embodiments the vial neck  204  comprises an outer surface that a threaded segment  212 , as illustrated in  FIGS. 1A-C . In some embodiments, the vial neck  204  comprises a female luer lock. The threaded vial neck or female luer lock can interface with a male luer lock (for example, on a syringe). In some embodiments, the inner portion of the vial neck  204  is tapered (that is, a bottom inner diameter proximal to the vial body is smaller than an upper inner diameter proximal to a vial opening). The vial cap  210  comprises the threaded segment  208  on the inside of a central opening of the vial cap  210 . The threaded segment  208  is located on the bottom portion (that is, the portion proximal to the vial) of the vial cap  210 . The vial cap  210  further comprises a plug  212 , which attaches to the vial cap  210  at the top portion of the vial cap  210 . Optionally, the outer surface of the vial cap  210  comprises a plurality of longitudinally disposed ribs, which can help provide traction when opening or closing the vial assembly. 
     The plug  212  comprises a stopper portion, a central body, a restraint, and a reduced diameter region defining an annulus between the central body and the restraint. The stopper portion of the plug  212  is disposed in the direction of the threaded segment of the vial cap and fits into the vial neck to form a seal. In some embodiments, the stopper portion is tapered (that is, a bottom inner diameter proximal to the vial body  202  is smaller than an upper inner diameter proximal to a vial opening). The central body is wider than the stopper portion, and can sit on the end of the vial neck  204  proximal to the vial opening. In some embodiments, the central body comprises a plurality of lateral compression ridges, which can aid in sealing the vial. The vial cap  210  comprises a rim  214  that extends into the annulus. The rim  214  can be formed, for example, by an aperture in the vial cap  210 . The aperture can extend through the top of the vial cap  210 , or the aperture can be internal in the bottle cap  210 . In some embodiments, the rim  214  comprises a plurality of prongs. The restraint locks the plug  212  into bottle cap  210  by extending over the rim  214  and holding the rim  214  in the annulus. 
     The restraint can be shaped to allow unidirectional movement, for example by having a narrower top and a wider base. For example, in some embodiments, the restraint is domed shaped. In some embodiments, the restraint comprises a beveled rim such that the top of the restraint is narrower than the base of the restraint. The rim that extends into the annulus can optionally comprise an angled edge. For example, the rim can comprise an angled edge such that the bottom edge of the rim is shorter than the top edge. In some embodiments, the rim comprises an angled edge such that a top portion or a bottom portion of the rim is beveled. The angled edge can be used alone or in combination with the restraint shaped to allow unidirectional movement to facilitate attachment of the plug into the vial cap. 
     In some embodiments, the vial cap is attached the vial by attaching the plug to vial cap and screwing the vial cap on to the vial neck. In some embodiments, the plug  21  is attached to the vial cap prior to fitting the stopper portion of the plug into the vial neck. In some embodiments, the stopper portion of the plug is fit into the vial neck prior to screwing the vial cap onto the vial neck, thereby positioning the rim of the vial cap into the annulus of the stopper. 
     A liquid  216  (such as a liquid medication) is dispensed into the vial body  202  through the open base  206 . The vial is filled vial cap  102  side down (i.e., the assembly is inverted) so that the liquid is retained in the vial body  202 . Optionally, the liquid  216  is lyophilized, thereby forming a powder  218 . Lyophilization can occur, for example, by freezing the liquid and exerting a vacuum pressure. Fluid can sublime or evaporate, and flow out of the open base  206 . The open base  206  is then sealed, (for example with a laminate  220 , such as a thermoformed plastic or a foil, which can be heated to form the seal). In some embodiments, the vial is sealed under vacuum pressure. In some embodiments, the vial is sealed under ambient pressure. 
     In some embodiments, the liquid is dispensed into the vial via the vial neck. In such an embodiment, the vial body does not comprise the open base, but the liquid is dispensed into the vial prior to attaching the vial cap. In some embodiments, the liquid is lyophilized prior to attaching the vial cap. 
     A user can fill a syringe by detaching the vial cap from the vial (for example, by unscrewing the vial cap), attaching the syringe to the syringe interface of the vial neck, and drawing liquid contained within the vial into the syringe. In some embodiments, unscrewing the vial cap comprises severing a tamper-evident band. The syringe can comprise a male luer, which can interface with the syringe interface (which may comprise, for example, threading on the outer surface of the vial neck or a female luer). In some embodiments, the syringe is pre-filled with a liquid, and that liquid is dispensed into the vial after attaching the syringe to the vial neck. If a powder is contained within the vial, for example, the liquid from the pre-filled syringe can be used to suspend or dissolve the powder before the liquid is drawn into the syringe. In some embodiments, the vial contains a first liquid, and the syringe can be pre-filled with a second liquid. The second liquid can be dispensed into the vial and mix with the first liquid before the mixture is drawn from the vial by the syringe. 
     In some embodiments, a method of filling a syringe comprises detaching a vial cap (for example, unscrewing the vial cap) from a vial, the vial having a vial body and a vial neck, the vial neck having a syringe interface; and the vial cap having a central opening including a threaded segment that engages the syringe interface and a plug, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the vial cap; attaching a syringe to the vial neck; and drawing a liquid contained within the vial into the syringe. In some embodiments, the vial neck has a tapered inner surface. In some embodiments, the syringe interface is a female luer. In some embodiments, the syringe interface is a second threaded segment on the outer surface of the vial neck. In some embodiments, the syringe comprises a male luer lock that interfaces with the syringe interface. In some embodiments, detaching the vial cap includes severing a tamper-evident band from the vial cap. In some embodiments, the method further comprises dispensing a liquid (which may be contained within the syringe) into the vial. 
     In some embodiments, a method of filling a syringe comprises detaching a vial cap (for example, unscrewing the vial cap) from a vial, the vial having a vial body and a vial neck, the vial neck having a syringe interface; and the vial cap having a central opening including a threaded segment that engages the syringe interface and a coextruded plug disposed with in the central opening, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the vial cap; attaching a syringe to the vial neck; and drawing a liquid contained within the vial into the syringe. In some embodiments, the vial neck has a tapered inner surface. In some embodiments, the syringe interface is a female luer. In some embodiments, the syringe interface is a second threaded segment on the outer surface of the vial neck. In some embodiments, the syringe comprises a male luer lock that interfaces with the syringe interface. In some embodiments, detaching the vial cap includes severing a tamper-evident band from the vial cap. In some embodiments, the method further comprises dispensing a liquid (which may be contained within the syringe) into the vial. 
     In some embodiments, a method of filling a syringe comprises detaching a vial cap (for example, unscrewing the vial cap) from a vial, the vial having a vial body and a vial neck, the vial neck having a syringe interface; and the vial cap having a central opening including a threaded segment that engages the syringe interface and a rim, said vial cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the vial neck, and an upper portion including a top portion defining a restraint coupled to a reduced diameter region defining an annulus, wherein the rim of the vial cap extends into the annulus to hold the plug in place; attaching a syringe to the vial neck; and drawing a liquid contained within the vial into the syringe. In some embodiments, the vial neck has a tapered inner surface. In some embodiments, the syringe interface is a female luer. In some embodiments, the syringe interface is a second threaded segment on the outer surface of the vial neck. In some embodiments, the syringe comprises a male luer lock that interfaces with the syringe interface. In some embodiments, detaching the vial cap includes severing a tamper-evident band from the vial cap. In some embodiments, the method further comprises dispensing a liquid (which may be contained within the syringe) into the vial. 
     In some embodiments, a method of filling a syringe comprises detaching a vial cap (for example, unscrewing the vial cap) from a vial, the vial having a vial body and a vial neck, the vial neck having a syringe interface; and the vial cap having a central opening including a threaded segment that engages the syringe interface and a rim, said vial cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the vial neck, and an upper portion including a top portion defining a restraint coupled to a reduced diameter region defining an annulus, wherein the rim of the vial cap extends into the annulus to hold the plug in place; attaching a syringe to the vial neck; and drawing a liquid contained within the vial into the syringe. In some embodiments, the vial neck has a tapered inner surface. In some embodiments, the syringe interface is a female luer. In some embodiments, the syringe interface is a second threaded segment on the outer surface of the vial neck. In some embodiments, the syringe comprises a male luer lock that interfaces with the syringe interface. In some embodiments, detaching the vial cap includes severing a tamper-evident band from the vial cap. In some embodiments, the method further comprises dispensing a liquid (which may be contained within the syringe) into the vial. 
     In some embodiments, a method of filling a syringe comprises detaching a vial cap (for example, unscrewing the vial cap) from a vial, the vial having a vial body and a vial neck, the vial neck having a syringe interface; and the vial cap having a central opening including a threaded segment that engages the syringe interface and a rim, said vial cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the vial neck, a central body with a diameter wider than the lower stopper portion (the central body optionally including a plurality of compression ridges), and an upper portion including a top portion defining a restraint (which can have a domed surface or a beveled rim) coupled to a reduced diameter region defining an annulus, wherein the rim of the vial cap extends into the annulus to hold the plug in place; attaching a syringe to the vial neck; and drawing a liquid contained within the vial into the syringe. In some embodiments, the vial neck has a tapered inner surface. In some embodiments, the syringe interface is a female luer. In some embodiments, the syringe interface is a second threaded segment on the outer surface of the vial neck. In some embodiments, the syringe comprises a male luer lock that interfaces with the syringe interface. In some embodiments, detaching the vial cap includes severing a tamper-evident band from the vial cap. In some embodiments, the method further comprises dispensing a liquid (which may be contained within the syringe) into the vial. 
     In another aspect, the vial assembly includes a vial and a two-component vial cap. The first component can screw on to a syringe interface, and the second component can attach to the first component using a downward motion (i.e., without the need to screw the second component onto the vial to seal the vial). This design allows for vials to be sealed on machinery that is not equipped for twisting on a vial cap. 
     In some embodiments, vial assembly comprises a vial having a vial body and a vial neck, the vial neck having a syringe interface; and a vial cap comprising a first component and a second component, said first component having an internal threaded segment that engages the syringe interface and an outer surface comprising a plurality of longitudinally extending ribs separated by a plurality of longitudinally extending channels, said second component including a plurality of longitudinally extending prongs that engage with a surface in the channels on the outer surface of the first component, said second component further including a central opening formed by the plurality of longitudinally extending prongs, and a plug disposed in the central opening, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the second component. 
     In some embodiments, the vial neck is tapered. In some embodiments, the syringe interface is a second threaded segment on an outer surface of the vial neck. In some embodiments, the syringe interface is a female luer. In some embodiments, the vial assembly comprises a tamper-evident band. 
     In some embodiments, vial assembly comprises a vial having a vial body and a vial neck, the vial neck having a syringe interface; and a vial cap comprising a first component and a second component, said first component having an internal threaded segment that engages the syringe interface and an outer surface comprising a plurality of longitudinally extending ribs separated by a plurality of longitudinally extending channels, said second component including a plurality of longitudinally extending prongs that engage with a surface in the channels on the outer surface of the first component, said second component further including a central opening formed by the plurality of longitudinally extending prongs, and a coextruded plug disposed in the central opening, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the second component. In some embodiments, the vial neck is tapered. In some embodiments, the syringe interface is a second threaded segment on an outer surface of the vial neck. In some embodiments, the syringe interface is a female luer. In some embodiments, the vial assembly comprises a tamper-evident band. 
     In some embodiments, vial assembly comprises a vial having a vial body and a vial neck, the vial neck having a syringe interface; and a vial cap comprising a first component and a second component, said first component having an internal threaded segment that engages the syringe interface and an outer surface comprising a plurality of longitudinally extending ribs separated by a plurality of longitudinally extending channels, said second component including a plurality of longitudinally extending prongs that engage with a surface in the channels on the outer surface of the first component, said second component further including a central opening formed by the plurality of longitudinally extending prongs and a rim, said vial cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the vial neck and an upper portion that includes a top portion defining a restraint coupled to a reduced diameter region defining an annulus, and wherein the rim of the second component extends into the annulus to hold the plug in place. In some embodiments, the vial neck is tapered. In some embodiments, the syringe interface is a second threaded segment on an outer surface of the vial neck. In some embodiments, the syringe interface is a female luer. In some embodiments, the vial assembly comprises a tamper-evident band. 
     In some embodiments, vial assembly comprises a vial having a vial body and a vial neck, the vial neck having a syringe interface; and a vial cap comprising a first component and a second component, said first component having an internal threaded segment that engages the syringe interface and an outer surface comprising a plurality of longitudinally extending ribs separated by a plurality of longitudinally extending channels, said second component including a plurality of longitudinally extending prongs that engage with a surface in the channels on the outer surface of the first component, said second component further including a central opening formed by the plurality of longitudinally extending prongs and a rim, said vial cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the vial neck, a central body with a diameter wider than the lower stopper portion (the central body optionally including a plurality of compression ridges), and an upper portion that includes a top portion defining a restraint (which can optionally have a domed surface or a beveled rim) coupled to a reduced diameter region defining an annulus, and wherein the rim of the second component extends into the annulus to hold the plug in place. In some embodiments, the vial neck is tapered. In some embodiments, the syringe interface is a second threaded segment on an outer surface of the vial neck. In some embodiments, the syringe interface is a female luer. In some embodiments, the vial assembly comprises a tamper-evident band. 
     In some embodiments, vial assembly comprises a vial having a vial body and a vial neck, the vial neck having a syringe interface; and a vial cap comprising a first component and a second component, said first component having an internal threaded segment that engages the syringe interface and an outer surface comprising a plurality of longitudinally extending ribs separated by a plurality of longitudinally extending channels, said second component including a plurality of longitudinally extending prongs, the prongs comprising an anchor that engages with a counter-anchor in the channels on the outer surface of the first component, said second component further including a central opening formed by the plurality of longitudinally extending prongs and a rim, said vial cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the vial neck, a central body with a diameter wider than the lower stopper portion (the central body optionally including a plurality of compression ridges), and an upper portion that includes a top portion defining a restraint (which can optionally have a domed surface or a beveled rim) coupled to a reduced diameter region defining an annulus, and wherein the rim of the second component extends into the annulus to hold the plug in place. In some embodiments, the vial neck is tapered. In some embodiments, the syringe interface is a second threaded segment on an outer surface of the vial neck. In some embodiments, the syringe interface is a female luer. In some embodiments, the vial assembly comprises a tamper-evident band. 
       FIG. 3A  illustrates an exemplary vial assembly comprising a vial  300  and a vial cap  302  next to a vial  300  without the vial cap. The vial comprises a vial body  304  and a vial neck  306 . The vial body can contain a liquid or a powder (which can be, for example, formed by lyophilizing a liquid). The vial neck  306  includes a syringe interface configured to engage a threaded segment of the vial cap. For example, in some embodiments the vial neck  306  comprises an outer surface that includes a threaded segment  308 , as illustrated in  FIG. 3A . In some embodiments, the vial neck  306  comprises a female luer lock. The threaded vial neck or female luer lock can interface with a male luer (for example, a male luer lock or male slip tip on a syringe). In some embodiments, the inner portion of the vial neck  306  is tapered (that is, a bottom inner diameter proximal to the vial body is smaller than an upper inner diameter proximal to a vial opening). The vial cap  302  comprises a first component  310  and a second component  312 . The first component  310  attached to the vial  300  is illustrated in  FIG. 3B , along with a close-up cross sectional view of the first component  310  attached to the vial  300 . The first component  310  comprises a threaded segment  314  on the surface of a central opening. The threaded segment  314  is located on the bottom portion of the first component  310 . The first component  310  further comprises a plurality of longitudinally disposed ribs  316  along the outer surface of the first component  310 . A plurality of longitudinally disposed channels  318  is disposed between the ribs  316  on the outer surface of the first component  310 . In some embodiments, a counter-anchor  320  is disposed in one or more channels in the plurality of channels  318 . 
       FIG. 3C  illustrates the second component  312  of the vial cap  302  disposed in an unsealed configuration, wherein the second component  312  is sitting on top of the first component  310 .  FIG. 3C  also illustrates a close-up cross-sectional view of the vial cap  302  disposed in the unsealed configuration. The second component  312  comprises a plurality of longitudinally disposed prongs  322  configured to engage the plurality of channels  318  in the first component  310 . The prongs  322  form a central opening of the second component  312 . The prongs  322  have a free lower end  324  and attach to a top  326  at the upper end  328  of the prongs. In some embodiments, the prongs  322  comprise an anchor  330 . In some embodiments, when the vial cap  302  is in the unsealed configuration, the anchor  330  sits above the counter anchor  320  in the channel  318 . In some embodiments, the counter anchor  320  has a sloped upper portion  332  that interfaces with a sloped lower portion  334  on the anchor  330 . The second component  312  further comprises a plug  336  disposed in the central opening. The plug  336  comprises a stopper portion  338 , a central body  340 , a restraint  342 , and a reduced diameter region defining an annulus  344  between the central body  340  and the restraint  342 . The stopper portion  338  of the plug is disposed in the direction of the plurality of prongs  322 . In some embodiments, the stopper portion  338  is tapered (that is, a bottom diameter is smaller than an upper diameter). The central body  340  is wider than the stopper portion  338 . In some embodiments, the central body  340  comprises a plurality of lateral compression ridges  346 , which can aid in sealing the vial. The second component  312  comprises a rim  348  that extends into the annulus  344  of the stopper  336 . The rim  348  can be formed, for example, by an aperture in the second component  312 . The aperture can extend through the top  326  of the second component  312 , or the aperture can be internal in the second component. In some embodiments, the rim  348  comprises a plurality of prongs. The restraint  342  locks the plug into second component  312  once attached by extending over the rim  348  and holding the rim  348  in the annulus  344 . 
     The restraint  342  can be shaped to allow unidirectional movement, for example by having a narrower top and a wider base. For example, in some embodiments, the restraint  342  is domed shaped. In some embodiments, the restraint  342  comprises a beveled rim  350  such that the top of the restraint  342  is narrower than the base of the restraint  342 . The rim  348  that extends into the annulus  344  can optionally comprise an angled edge  352 . For example, the rim  348  can comprise an angled edge  352  such that the bottom edge of the rim  348  is shorter than the top edge. In some embodiments, the rim  348  comprises an angled edge  352  such that a top portion or a bottom portion of the rim  348  is beveled. In the cap illustrated in  FIG. 3C , the bottom potion of the rim  348  is beveled, thereby forming the angled edge  352 . The angled edge  352  can be used alone or in combination with the restraint  342  shaped to allow unidirectional movement to facilitate attachment of the plug  336  into the second component  312  of the vial cap  302 . 
     When the second component  312  of the vial cap  302  is disposed in the unsealed configuration, the vial body is fluidly connected to the ambient environment. As depicted by the arrows in  FIG. 3C , evaporating or subliming fluids (for example, during lyophilization) can flow through the vial neck  306 , through the upper portion of the first component  310  and around the stopper portion  338  of the plug  336 , and out to the ambient environment in vents  354  that form between the prongs  322  in the second component  312 . 
     The second component  312  of the vial cap  302  can be pressed down towards the vial  300  to position the vial cap  302  in a sealed configuration, as illustrated in  FIG. 3A . A cross-sectional view of the vial cap  302  in the sealed configuration is illustrated in  FIG. 3D . In the sealed configuration, the stopper portion  338  of the plug  336  fits into the vial neck  306 , forming a seal. The central body  340  sits against the end of the vial neck  306  proximal to the vial opening. The anchors  330  on the prongs  322  can engage the bottom of the counter-anchors  320  in the channels  318 . Once the anchors  330  engage the counter-anchors  320 , the second component  312  is irreversibly attached to the first component  310 . 
     In some embodiments, the vial assembly comprises a tamper-evident band ( FIG. 3E ). For example, in some embodiments, the vial comprises an annular lip  356  disposed on the outer surface of the vial neck  306 . The annular lip  356  is disposed on the proximal end of the vial neck  306  (i.e., closer to the vial body than the vial opening). The tamper-evident band  358  is attached to the vial cap  302  (for example, on the bottom of the first component  310  or the second component  320 ) and wraps below the annular lip  356  on the vial neck  306 . The tamper-evident band  358  can be attached to the vial cap  302  by a perforated segment  360 . When the vial cap  302  is separated from the vial  300 , the annular lip on the vial neck  306  retains the tamper-evident band and the perforated segment is torn, thereby separating the tamper-evident band from the vial cap  302 . This separation indicates that the vial cap  302  has been opened. 
     The vial  300  can be filled with a liquid (for example, a liquid medication) from either vial neck  306  opening or from the base of the vial body  302 . That is, in some embodiments, the vial body  304  comprises an open base  328 , which can be sealed after a liquid is dispensed in the vial (for example using a thermoformed plastic or foil). When dispensing liquid into the vial  300  through the open base, the assembled vial cap  302  (that is, the first component  310  and the second component  312  in the sealed configuration) is attached to the vial  300  prior to dispensing the liquid into the vial  300 . 
     In some embodiments, a method of filling a vial assembly comprises dispensing a liquid into a vial comprising a vial body and a vial neck, the vial neck having a syringe interface; attaching a first component of a vial cap to the vial neck, said first component having an internal threaded segment that engages the syringe interface and an outer surface comprising a plurality of longitudinally extending ribs separated by a plurality of longitudinally extending channels; and sealing the vial by attaching a second component of the vial cap to the first component, said second component including a plurality of longitudinally extending prongs that engage with a surface in the channels on the outer surface of the first component, said second component further including a central opening formed by the plurality of longitudinally extending prongs and a plug disposed in the central opening, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the second component. In some embodiments, the vial neck is tapered. In some embodiments, the syringe interface is a second threaded segment on an outer surface of the vial neck. In some embodiments, the syringe interface is a female luer. In some embodiments, the liquid is dispensed into the vial prior to attaching the first component to the vial neck, and in some embodiments, the first component is attached to the vial neck prior to dispensing the liquid into the vial. In some embodiments, the liquid is lyophilized prior to sealing the vial. 
     In some embodiments, a method of filling a vial assembly comprises dispensing a liquid into a vial comprising a vial body and a vial neck, the vial neck having a syringe interface; attaching a first component of a vial cap to the vial neck, said first component having an internal threaded segment that engages the syringe interface and an outer surface comprising a plurality of longitudinally extending ribs separated by a plurality of longitudinally extending channels; and sealing the vial by attaching a second component of the vial cap to the first component, said second component including a plurality of longitudinally extending prongs that engage with a surface in the channels on the outer surface of the first component, said second component further including a central opening formed by the plurality of longitudinally extending prongs and a coextruded plug disposed in the central opening, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the second component. In some embodiments, the vial neck is tapered. In some embodiments, the syringe interface is a second threaded segment on an outer surface of the vial neck. In some embodiments, the syringe interface is a female luer. In some embodiments, the liquid is dispensed into the vial prior to attaching the first component to the vial neck, and in some embodiments, the first component is attached to the vial neck prior to dispensing the liquid into the vial. In some embodiments, the liquid is lyophilized prior to sealing the vial. 
     In some embodiments, a method of filling a vial assembly comprises dispensing a liquid into a vial comprising a vial body and a vial neck, the vial neck having a syringe interface; attaching a first component of a vial cap to the vial neck, said first component having an internal threaded segment that engages the syringe interface and an outer surface comprising a plurality of longitudinally extending ribs separated by a plurality of longitudinally extending channels; and sealing the vial by attaching a second component of the vial cap to the first component, said second component including a plurality of longitudinally extending prongs that engage with a surface in the channels on the outer surface of the first component, said second component further including a central opening formed by the plurality of longitudinally extending prongs and a rim, said vial cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the vial neck and an upper portion that includes a top portion defining a restraint coupled to a reduced diameter region defining an annulus, and wherein the rim of the second component extends into the annulus to hold the plug in place. In some embodiments, the vial neck is tapered. In some embodiments, the syringe interface is a second threaded segment on an outer surface of the vial neck. In some embodiments, the syringe interface is a female luer. In some embodiments, the liquid is dispensed into the vial prior to attaching the first component to the vial neck, and in some embodiments, the first component is attached to the vial neck prior to dispensing the liquid into the vial. In some embodiments, the liquid is lyophilized prior to sealing the vial. 
     In some embodiments, a method of filling a vial assembly comprises dispensing a liquid into a vial comprising a vial body and a vial neck, the vial neck having a syringe interface; attaching a first component of a vial cap to the vial neck, said first component having an internal threaded segment that engages the syringe interface and an outer surface comprising a plurality of longitudinally extending ribs separated by a plurality of longitudinally extending channels; and sealing the vial by attaching a second component of the vial cap to the first component, said second component including a plurality of longitudinally extending prongs that engage with a surface in the channels on the outer surface of the first component, said second component further including a central opening formed by the plurality of longitudinally extending prongs and a rim, said vial cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the vial neck, a central body with a diameter wider than the lower stopper portion (the central body optionally including a plurality of compression ridges), and an upper portion that includes a top portion defining a restraint (which can optionally have a domed surface or a beveled rim) coupled to a reduced diameter region defining an annulus, and wherein the rim of the second component extends into the annulus to hold the plug in place. In some embodiments, the vial neck is tapered. In some embodiments, the syringe interface is a second threaded segment on an outer surface of the vial neck. In some embodiments, the syringe interface is a female luer. In some embodiments, the liquid is dispensed into the vial prior to attaching the first component to the vial neck, and in some embodiments, the first component is attached to the vial neck prior to dispensing the liquid into the vial. In some embodiments, the liquid is lyophilized prior to sealing the vial. 
     In some embodiments, a method of filling a vial assembly comprises dispensing a liquid into a vial comprising a vial body and a vial neck, the vial neck having a syringe interface; attaching a first component of a vial cap to the vial neck, said first component having an internal threaded segment that engages the syringe interface and an outer surface comprising a plurality of longitudinally extending ribs separated by a plurality of longitudinally extending channels; and sealing the vial by attaching a second component of the vial cap to the first component, said second component including a plurality of longitudinally extending prongs that engage with a surface in the channels on the outer surface of the first component, said second component further including a central opening formed by the plurality of longitudinally extending prongs and a rim, said vial cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the vial neck, a central body with a diameter wider than the lower stopper portion (the central body optionally including a plurality of compression ridges), and an upper portion that includes a top portion defining a restraint (which can optionally have a domed surface or a beveled rim) coupled to a reduced diameter region defining an annulus, and wherein the rim of the second component extends into the annulus to hold the plug in place, wherein sealing the vial includes engaging an anchor on at least one of the prongs in the plurality of longitudinally disposed prongs with a counter-anchor disposed in a channel in the plurality of longitudinally disposed channels. In some embodiments, the vial neck is tapered. In some embodiments, the syringe interface is a second threaded segment on an outer surface of the vial neck. In some embodiments, the syringe interface is a female luer. In some embodiments, the liquid is dispensed into the vial prior to attaching the first component to the vial neck, and in some embodiments, the first component is attached to the vial neck prior to dispensing the liquid into the vial. In some embodiments, the liquid is lyophilized prior to sealing the vial. 
     In some embodiments, the vial is filled with a liquid via the vial neck.  FIG. 4  illustrates one embodiment of a method for filling a vial assembly comprising a vial cap with a first component and a second component. The vial  400  comprises a vial body  402  and a vial neck  404 . The vial neck  404  includes a syringe interface configured to engage a threaded segment on an inner central opening of the first component  406  of the vial cap. For example, in some embodiments the vial neck  404  comprises an outer surface that a threaded segment, as illustrated in  FIGS. 3A-D . In some embodiments, the vial neck  404  comprises a female luer lock. The threaded vial neck or female luer lock can interface with a male luer lock (for example, on a syringe). In some embodiments, the inner portion of the vial neck  404  is tapered (that is, a bottom inner diameter proximal to the vial body is smaller than an upper inner diameter proximal to a vial opening). The first component  406  of the vial cap comprises a threaded segment on bottom portion of its inner surface, which can engage with the syringe interface on the vial neck  404 . The first component  406  is attached to the vial neck  404  (for example, by screwing the first component  406  onto the vial neck  404 ) and a liquid  408  is dispensed into the vial  400 . In some embodiments, the first component  406  is attached to the vial neck  404  (for example, by screwing the first component  406  onto the vial neck  404 ) prior to dispensing the liquid  408  into the vial  400 . In some embodiments, the liquid  408  is dispensed into the vial  400  prior to attaching the first component  406  onto the vial neck  404  (for example, by screwing the first component  406  onto the vial neck  404 ). 
     The vial can be sealed by attaching the second component  408  to the first component  406 . The second component  408  comprises a plurality of longitudinally disposed prongs configured to engage a plurality of channels on the outer surface of the first component  406 . The channels are disposed between a ridges present on the outer surface of the first component  406 . The prongs have a free lower end and attach to a top at the upper end of the prongs. In some embodiments, the prongs comprise an anchor that can engage a counter-anchor disposed in a channel in the plurality of channels. Once the anchors engage the lip disposed in the channels, the second component is irreversibly attached to the first component. The second component  408  can be positioned proximal to the first component  406  such that the plurality of prongs is partially engaged with the plurality of channels. A downward pressure can then be exerted on the second component  408 , thereby fully engaging the plurality of prongs with the plurality of channels, and (if present), engaging the anchors on the prongs with the counter-anchors disposed in the channels. 
     The second component  408  further comprises a plug that seals the neck vial  404  when the second component  408  is attached to the first component  406 , and the first component is attached to the vial neck. The plug comprises a lower stopper portion, a central body, a restraint, and a reduced diameter region defining an annulus between the central body and the restraint. The stopper portion of the plug is disposed in the direction of the plurality of prongs. In some embodiments, the stopper portion is tapered (that is, a bottom diameter is smaller than an upper diameter). The central body is wider than the stopper portion. In some embodiments, the central body comprises a plurality of lateral compression ridges, which can aid in sealing the vial. The second component comprises a rim that extends into the annulus of the stopper. The rim can be formed, for example, by an aperture in the second component. The aperture can extend through the top of the second component, or the aperture can be internal in the second component. In some embodiments, the rim comprises a plurality of prongs. The restraint locks the plug into second component  408  once attached by extending over the rim and holding the rim in the annulus. In some embodiments, the plug is attached to the second component  408 , for example by pushing the restraint of the plug through the aperture forming the rim. 
     In some embodiments, the second component  408  is partially engaged with the first component  406  prior to sealing the vial. That is, in some embodiments, the vial cap is configured in an unsealed configuration, for example by setting the second component on the first component wherein the plurality of legs is partially engaged with the plurality of channels. In some embodiments, when the vial cap is in the unsealed configuration, the anchors on the prongs of the second component  408  sit above the counter anchors in the channels of the first components. In some embodiments, the counter anchor has a sloped upper portion that interfaces with a sloped lower portion on the anchor. When the vial cap is in the unsealed configuration, the liquid in the vial is fluidly connected to the atmospheric environment. Optionally, the liquid  408  in the vial is lyophilized when the cap is in the unsealed configuration, thereby forming a powder  410 . Lyophilization can occur, for example, by freezing the liquid and exerting a vacuum pressure. The vial can then be sealed after lyophilization. Lyophilization can occur at any time during the process after dispensing the liquid into the vial and before sealing the vial. For example, the liquid can by lyophilized after dispensing the liquid and prior to attaching the first component to the vial neck, after attaching the first component to the vial neck and prior to partially engaging the second component with the first component, or after partially engaging the second component with the first component and prior to sealing the vial. 
     A user can fill a syringe by detaching (for example, by unscrewing) the vial cap comprising the first component and the second component from the vial, attaching the syringe to the syringe interface of the vial neck, and drawing liquid contained within the vial into the syringe. In some embodiments, unscrewing the vial cap comprises severing a tamper-evident band. The syringe can comprise a male luer, which can interface with the syringe interface (which may comprise, for example, threading on the outer surface of the vial neck or a female luer). In some embodiments, the syringe is pre-filled with a liquid, and that liquid is dispensed into the vial after attaching the syringe to the vial neck. If a powder is contained within the vial, for example, the liquid from the pre-filled syringe can be used to suspend or dissolve the powder before the liquid is drawn into the syringe. In some embodiments, the vial contains a first liquid, and the syringe can be pre-filled with a second liquid. The second liquid can be dispensed into the vial and mix with the first liquid before the mixture is drawn from the vial by the syringe. 
     In some embodiments, a method of filling a syringe comprises detaching (for example, by unscrewing) the vial cap from a vial, the vial having a vial body and a vial neck, the vial neck having a syringe interface; and the vial cap comprising a first component and a second component, said first component having an internal threaded segment that engages the syringe interface and an outer surface comprising a plurality of longitudinally extending ribs separated by a plurality of longitudinally extending channels, said second component including a plurality of longitudinally extending prongs that engage with a surface in the channels on the outer surface of the first component, said second component further including a central opening formed by the plurality of longitudinally extending prongs and a plug disposed therein, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the second component; attaching a syringe (which can include a male luer, such as a male luer lock or a male luer slip) to the syringe interface of the vial neck; and drawing a liquid contained within the vial into the syringe. In some embodiments, the vial neck is tapered. In some embodiments, the syringe interface is a second threaded segment on an outer surface of the vial neck. In some embodiments, the syringe interface is a female luer. In some embodiments, the method further comprises dispensing a liquid into the vial to dissolve or suspending a lyophilized powder. In some embodiments, the liquid is contained within the syringe. 
     In some embodiments, a method of filling a syringe comprises detaching (for example, by unscrewing) the vial cap from a vial, the vial having a vial body and a vial neck, the vial neck having a syringe interface; and the vial cap comprising a first component and a second component, said first component having an internal threaded segment that engages the syringe interface and an outer surface comprising a plurality of longitudinally extending ribs separated by a plurality of longitudinally extending channels, said second component including a plurality of longitudinally extending prongs that engage with a surface in the channels on the outer surface of the first component, said second component further including a central opening formed by the plurality of longitudinally extending prongs and a coextruded plug disposed in the central opening, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the second component; attaching a syringe (which can include a male luer, such as a male luer lock or a male luer slip) to the syringe interface of the vial neck; and drawing a liquid contained within the vial into the syringe. In some embodiments, the vial neck is tapered. In some embodiments, the syringe interface is a second threaded segment on an outer surface of the vial neck. In some embodiments, the syringe interface is a female luer. In some embodiments, the method further comprises dispensing a liquid into the vial to dissolve or suspending a lyophilized powder. In some embodiments, the liquid is contained within the syringe. 
     In some embodiments, a method of filling a syringe comprises detaching (for example, by unscrewing) the vial cap from a vial, the vial having a vial body and a vial neck, the vial neck having a syringe interface; and the vial cap comprising a first component and a second component, said first component having an internal threaded segment that engages the syringe interface and an outer surface comprising a plurality of longitudinally extending ribs separated by a plurality of longitudinally extending channels, said second component including a plurality of longitudinally extending prongs that engage with a surface in the channels on the outer surface of the first component, said second component further including a central opening formed by the plurality of longitudinally extending prongs and a rim, said vial cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the vial neck and an upper portion that includes a top portion defining a restraint coupled to a reduced diameter region defining an annulus, and wherein the rim of the second component extends into the annulus to hold the plug in place; attaching a syringe (which can include a male luer, such as a male luer lock or a male luer slip) to the syringe interface of the vial neck; and drawing a liquid contained within the vial into the syringe. In some embodiments, the vial neck is tapered. In some embodiments, the syringe interface is a second threaded segment on an outer surface of the vial neck. In some embodiments, the syringe interface is a female luer. In some embodiments, the method further comprises dispensing a liquid into the vial to dissolve or suspending a lyophilized powder. In some embodiments, the liquid is contained within the syringe. 
     In some embodiments, a method of filling a syringe comprises detaching (for example, by unscrewing) the vial cap from a vial, the vial having a vial body and a vial neck, the vial neck having a syringe interface; and the vial cap comprising a first component and a second component, said first component having an internal threaded segment that engages the syringe interface and an outer surface comprising a plurality of longitudinally extending ribs separated by a plurality of longitudinally extending channels, said second component including a plurality of longitudinally extending prongs that engage with a surface in the channels on the outer surface of the first component, said second component further including a central opening formed by the plurality of longitudinally extending prongs and a rim, said vial cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the vial neck, a central body with a diameter wider than the lower stopper portion (the central body optionally including a plurality of compression ridges), and an upper portion that includes a top portion defining a restraint (which can optionally have a domed surface or a beveled rim) coupled to a reduced diameter region defining an annulus, and wherein the rim of the second component extends into the annulus to hold the plug in place; attaching a syringe (which can include a male luer, such as a male luer lock or a male luer slip) to the syringe interface of the vial neck; and drawing a liquid contained within the vial into the syringe. In some embodiments, the vial neck is tapered. In some embodiments, the syringe interface is a second threaded segment on an outer surface of the vial neck. In some embodiments, the syringe interface is a female luer. In some embodiments, the method further comprises dispensing a liquid into the vial to dissolve or suspending a lyophilized powder. In some embodiments, the liquid is contained within the syringe. 
     In some embodiments, a method of filling a syringe comprises detaching (for example, by unscrewing) the vial cap from a vial, the vial having a vial body and a vial neck, the vial neck having a syringe interface; and the vial cap comprising a first component and a second component, said first component having an internal threaded segment that engages the syringe interface and an outer surface comprising a plurality of longitudinally extending ribs separated by a plurality of longitudinally extending channels, said second component including a plurality of longitudinally extending prongs, the prongs comprising an anchor that engages with a counter-anchor in the channels on the outer surface of the first component, said second component further including a central opening formed by the plurality of longitudinally extending prongs and a rim, said vial cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the vial neck, a central body with a diameter wider than the lower stopper portion (the central body optionally including a plurality of compression ridges), and an upper portion that includes a top portion defining a restraint (which can optionally have a domed surface or a beveled rim) coupled to a reduced diameter region defining an annulus, and wherein the rim of the second component extends into the annulus to hold the plug in place; attaching a syringe (which can include a male luer, such as a male luer lock or a male luer slip) to the syringe interface of the vial neck; and drawing a liquid contained within the vial into the syringe. In some embodiments, the vial neck is tapered. In some embodiments, the syringe interface is a second threaded segment on an outer surface of the vial neck. In some embodiments, the syringe interface is a female luer. In some embodiments, the method further comprises dispensing a liquid into the vial to dissolve or suspending a lyophilized powder. In some embodiments, the liquid is contained within the syringe. 
     In another aspect, there is provided a vial assembly comprising a vial having a vial body and a vial neck; an adapter comprising a top portion having a syringe interface, a bottom portion having a vial neck fitting attached to the vial neck, and a channel fluidly connecting the syringe interface to the vial neck; a gasket disposed between the vial neck and the adapter; and a vial cap having a central opening including a threaded segment that engages the syringe interface and a plug, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the vial cap. In some embodiments, the vial cap comprises an end cap that surrounds a portion of the vial neck fitting. In some embodiments, the syringe interface is a tapered conduit. In some embodiments, the syringe interface is a second threated segment on an outer surface of a conduit. In some embodiments, the syringe interface is a female luer. In some embodiments, the vial assembly comprises a tamper-evident band. 
     In some embodiments, the vial assembly comprises a vial having a vial body and a vial neck; an adapter comprising a top portion having a syringe interface, a bottom portion having a vial neck fitting attached to the vial neck, and a channel fluidly connecting the syringe interface to the vial neck; a gasket disposed between the vial neck and the adapter; and a vial cap having a central opening including a threaded segment that engages the syringe interface and a coextruded plug, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the vial cap. In some embodiments, the vial cap comprises an end cap that surrounds a portion of the vial neck fitting. In some embodiments, the syringe interface is a tapered conduit. In some embodiments, the syringe interface is a second threated segment on an outer surface of a conduit. In some embodiments, the syringe interface is a female luer. In some embodiments, the vial assembly comprises a tamper-evident band. 
     In some embodiments, the vial assembly comprises a vial having a vial body and a vial neck; an adapter comprising a top portion having a syringe interface, a bottom portion having a vial neck fitting attached to the vial neck, and a channel fluidly connecting the syringe interface to the vial neck; a gasket disposed between the vial neck and the adapter; and a vial cap having a central opening including a threaded segment that engages the syringe interface and a rim, said vial cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the vial neck, and an upper portion including a top portion defining a restraint coupled to a reduced diameter region defining an annulus, wherein the rim of the vial cap extends into the annulus to hold the plug in place. In some embodiments, the vial cap comprises an end cap that surrounds a portion of the vial neck fitting. In some embodiments, the syringe interface is a tapered conduit. In some embodiments, the syringe interface is a second threated segment on an outer surface of a conduit. In some embodiments, the syringe interface is a female luer. In some embodiments, the vial assembly comprises a tamper-evident band. 
     In some embodiments, the vial assembly comprises a vial having a vial body and a vial neck; an adapter comprising a top portion having a syringe interface, a bottom portion having a vial neck fitting attached to the vial neck, and a channel fluidly connecting the syringe interface to the vial neck; a gasket disposed between the vial neck and the adapter; and a vial cap having a central opening including a threaded segment that engages the syringe interface and a rim, said vial cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the vial neck, a central body with a diameter wider than the lower stopper portion (the central body optionally including a plurality of compression ridges), and an upper portion including a top portion defining a restraint (which can have a domed surface or a beveled rim) coupled to a reduced diameter region defining an annulus, wherein the rim of the vial cap extends into the annulus to hold the plug in place. In some embodiments, the vial cap comprises an end cap that surrounds a portion of the vial neck fitting. In some embodiments, the syringe interface is a tapered conduit. In some embodiments, the syringe interface is a second threated segment on an outer surface of a conduit. In some embodiments, the syringe interface is a female luer. In some embodiments, the vial assembly comprises a tamper-evident band. 
     In some embodiments, the vial assembly comprises a vial having a vial body and a vial neck; an adapter comprising a top portion having a syringe interface, a bottom portion having a vial neck fitting comprising a plurality of prongs comprising an anchor that engages an annular lip disposed on the vial neck, and a channel fluidly connecting the syringe interface to the vial neck; a gasket disposed between the vial neck and the adapter; and a vial cap having a central opening including a threaded segment that engages the syringe interface and a rim, said vial cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the vial neck, a central body with a diameter wider than the lower stopper portion (the central body optionally including a plurality of compression ridges), and an upper portion including a top portion defining a restraint (which can have a domed surface or a beveled rim) coupled to a reduced diameter region defining an annulus, wherein the rim of the vial cap extends into the annulus to hold the plug in place. In some embodiments, the vial cap comprises an end cap that surrounds a portion of the vial neck fitting. In some embodiments, the syringe interface is a tapered conduit. In some embodiments, the syringe interface is a second threated segment on an outer surface of a conduit. In some embodiments, the syringe interface is a female luer. In some embodiments, the vial assembly comprises a tamper-evident band. 
     In some embodiments, the vial assembly comprises a vial having a vial body and a vial neck; an adapter comprising a top portion having a syringe interface, a bottom portion having a vial neck fitting comprising a plurality of prongs comprising an anchor that engage an annular lip disposed on the vial neck, and a channel fluidly connecting the syringe interface to the vial neck; a gasket disposed along an inner edge of the vial neck fitting, proximal to a lateral disk joining the plurality of prongs, and proximal to an opening on the vial neck; and a vial cap having a central opening including a threaded segment that engages the syringe interface and a rim, said vial cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the vial neck, a central body with a diameter wider than the lower stopper portion (the central body optionally including a plurality of compression ridges), and an upper portion including a top portion defining a restraint (which can have a domed surface or a beveled rim) coupled to a reduced diameter region defining an annulus, wherein the rim of the vial cap extends into the annulus to hold the plug in place. In some embodiments, the vial cap comprises an end cap that surrounds a portion of the vial neck fitting. In some embodiments, the syringe interface is a tapered conduit. In some embodiments, the syringe interface is a second threated segment on an outer surface of a conduit. In some embodiments, the syringe interface is a female luer. In some embodiments, the vial assembly comprises a tamper-evident band. 
       FIG. 5A  illustrates an exemplary embodiment of a vial assembly in a fully assembled, partially assembled, and an unassembled configuration, the vial assembly comprising a vial  500 , an adapter  502 , and a vial cap  504 . The vial  500  comprises a vial body  506  and a vial neck  508 . The adapter  502  comprises a syringe interface  510  and a vial neck fitting  512 . The syringe interface  510  is configured to engage a threated segment on the inner surface of the vial cap  504 . The syringe interface  510  can be, for example, a conduit with a threaded outer surface or a female luer lock (as illustrated in  FIG. 5A ). The syringe interface  510  can engage a male luer lock or slip tip (for example, on a syringe). In some embodiments, the inner portion of the syringe interface  510  is tapered (that is, the syringe interface has an inner diameter proximal to vial neck fitting  512  that is narrower than the distal inner diameter). The vial neck fitting comprises a plurality of prongs  514  that are directed away from the syringe interface  510 . The vial neck  508  comprises an annular lip  516 , and the prongs  514  comprise an anchor  518  that can engage with the annular lip  516 .  FIG. 5B  illustrates a close-up cross-sectional view of the adapter  502  and vial cap  504  assembled on the vial  500 . Once the anchors  518  engage the annular lip  516  from the underside of the lip  516 , the adapter  502  is irreversibly positioned on the vial neck  508 . A channel  544  in the adapter  502  fluidly connects the vial neck  508  to the syringe interface. 
     The vial cap  504  has a threaded inner segment  520  that engages the syringe interface  510 . Thus, the vial cap  504  can attach to the adapter  502  by screwing the vial cap  504  on to the syringe interface  510 . The vial cap  504  is attached to a plug  522 . The plug  522  comprises a stopper portion  524 , which can fit into the syringe interface  510  to form a seal. In some embodiments, the stopper portion  524  is tapered (that is, a bottom diameter is smaller than an upper diameter). The plug  522  further comprises a central body  526 , a restraint  528 , and a reduced diameter region defining an annulus  530  between the central body  526  and the restraint  528 . The central body  526  of the plug  522  is wider than the stopper portion  524 , and can sit on the opening of the syringe interface  510 . The vial cap  504  comprises a rim  532  that extends into the annulus  530 . The rim  532  can be formed, for example, by an aperture in the vial cap  504 . The aperture can extend through the top of the vial cap  504 , or the aperture can be internal in the vial cap. In some embodiments, the rim  532  comprises a plurality of prongs. The restraint  528  locks the plug into the vial cap  504  once attached by extending over the rim  532  and holding the rim  532  in the annulus  530 . 
     The restraint  528  can be shaped to allow unidirectional movement, for example by having a narrower top and a wider base. For example, in some embodiments, the restraint  528  is domed shaped. In some embodiments, the restraint  528  comprises a beveled rim  534  such that the top of the restraint is narrower than the base of the restraint. The rim  532  that extends into the annulus  530  can optionally comprise an angled edge  536 . For example, the rim  532  can comprise an angled edge  536  such that the bottom edge of the rim is shorter than the top edge. The angled edge  536  can be used alone or in combination with the restraint  528  shaped to allow unidirectional movement to facilitate attachment of the plug  522  into the vial cap  504 . 
     In some embodiments, the vial cap  504  comprises a skirt  538  that surrounds a portion of the vial neck fitting  512  of the adapter  502 . Optionally, the outer surface of the vial cap  504  comprises a plurality of longitudinally disposed ribs  540 , which can help provide traction when opening or closing the vial assembly. The ribs can be disposed on the upper portion of the vial cap  504 , but they can also or alternatively be disposed on the skirt  538 , if present. 
     In some embodiments, the vial assembly further includes a gasket  542 , which can be made from rubber, a polymer, or any other suitable material. The gasket  542  is disposed between the adapter  502  and the opening of the vial neck  508  (for example, disposed on top of the annular ring  516 , if present). The gasket  542  forms a seal between the vial neck  508  and the adapter  502  to limit leakage of the liquid in vial  500 . Thus, once the adapter  502  is attached to the vial neck  508  with the gasket  542  in place, liquid is limited to exiting the vial through the syringe interface  510  via the channel  544  in the adapter  502 . The gasket  542  can be fit into the vial neck fitting  512  of the adapter  502  prior to attaching the adapter  502  to the vial neck  516 . For example, the outer edge of the gasket  542  can be disposed along the inner edge of the vial neck fitting above the top of the prongs  514 . The top of the gasket  542  can fit proximal to a lateral disk  546  that connects the prongs  514 . In some embodiments, the adapter  502  comprises a protrusion  548 , and the outer surface of the protrusion can contact the inner surface of the gasket  542  while the channel  544  continues through the protrusion  548 . In some embodiments, the protrusion  548  has a narrower top to hold the gasket  542  in place. In some embodiments, the protrusion comprises a conical or frustoconical bottom. 
     The vial cap  504  can be attached to the adapter  504  in a sealed or an unsealed configuration.  FIG. 5C  provides a side-by-side view of the sealed and unsealed configurations. When the vial cap is placed on the adapter or the inner threaded segment  520  of the vial cap is only partially engaged with the syringe interface  510 , the vial assembly is in the unsealed configuration. In the unsealed configuration, the stopper portion  524  of the plug is unengaged or only partially engaged (as illustrated in  FIG. 5C ) such that the central body  526  does not sit on the end of the syringe interface  510 . The vial cap can be tightened, for example by twisting the vial cap, to fully engage the inner threaded segment  520  of the vial cap with the syringe interface  510 . By tightening the vial cap, the plug is lowered towards the adapter. Thus, in the sealed configuration, the stopper portion  524  of the plug is fully engaged in the syringe interface  510 , and the central body  526  sits on the end of the syringe interface  510 . 
     When the vial assembly is in the unsealed configuration, the liquid in the vial is fluidly connected to the atmospheric environment. Optionally, the liquid contained within the vial is lyophilized when the vial assembly is in the unsealed configuration. Lyophilization can occur, for example, by freezing the liquid and exerting a vacuum pressure. Fluid (such as evaporated or sublimed gas formed during lyophilization of the liquid contained within the vial) can flow through the vial neck  508 , channel  544 , and syringe interface  510 ; around the stopper portion  524  of the plug and inner threaded segment  520  of the vial cap; and through spaces between the prongs  514  in the adapter into the atmosphere. 
     In some embodiments, the vial assembly includes a tamper-evident band ( FIG. 5D ). For example, in some embodiments, the vial includes an annular lip  550  disposed on the outer surface of the vial neck  508 . The annular lip  550  is disposed on the proximal end of the vial neck  508  (i.e., closer to the vial body than the vial opening). The tamper-evident band  552  is attached to the vial cap (for example, at the skirt of the vial cap) and wraps below the annular lip  550  on the vial neck  508 . Alternatively, the tamper-evident band wraps below the prongs on the adapter. In some embodiments, the tamper-evident band can be attached to the vial cap by a perforated segment  554 . When the vial cap is separated from the vial, the annular lip on the vial neck (or the prongs on the adapter) retains the tamper-evident band and the perforated segment is torn, thereby separating the tamper-evident band from the vial cap. This separation indicates that the vial cap has been opened. 
     The vial assembly can be filled by dispensing a liquid into a vial having a vial body and a vial neck; attaching an adapter to the vial neck, the adapter having a syringe interface, a vial neck fitting, and a longitudinally disposed channel; and sealing the vial by attaching a vial cap to the adapter, the vial cap having a threaded interior portion that engages the syringe interface and a plug having a stopper portion fitted into the syringe interface. 
     The adapter can be attached to the vial neck by placing the adapter on the end of the vial neck and exerting a downward force. The adapter includes a vial neck fitting that interfaces with and irreversibly attaches the adapter to the vial neck. For example, the vial neck fitting can have a plurality of prongs, the prongs having an anchor that engages an annular lip disposed on the outer surface of the vial neck. The adapter also includes a syringe interface and a channel fluidly connecting the syringe interface to the vial neck. The syringe interface can be, for example, a female luer lock or a conduit with a threaded outer surface. 
     In some embodiments, a gasket is placed between the adapter and the end of the vial neck. In some embodiments, the gasket is placed on the end of the vial neck, and it in some embodiments, the gasket is positioned in the vial neck fitting of the adapter prior to attaching the adapter to the vial neck. Once the adapter is attached to the vial neck, the gasket forms a seal between the vial neck and the adapter. 
     A liquid (such as a liquid medication) can be dispensed into the vial either before or after the adapter is attached the vial neck. For example, in some embodiments, the liquid is dispensed into the vial via the vial neck, and then the adapter is attached the vial neck. In some embodiments, the adapter is attached to the vial neck, and the liquid is dispensed into the vial via a syringe interface disposed on the top of the adapter. The liquid can flow through the syringe interface, the channel, the vial neck, and into the body of the vial. 
     After liquid has been dispensed in the vial, the vial cap can then be attached to the adapter in either a sealed configuration or an unsealed configuration. The vial cap can include a threaded segment on the inner surface of the vial cap that can engage the syringe interface on the adapter. The vial cap can be attached to the adapter by partially engaging the threaded segment with the syringe interface in an unsealed configuration. For example, when the vial cap is placed on the adapter or the inner threaded segment of the vial cap is only partially engaged with the syringe interface, the vial assembly is in the unsealed configuration. In the unsealed configuration, a stopper portion of a plug is unengaged or only partially engaged (as illustrated in  FIG. 5C ) such that the central body does not sit on the end of the syringe interface. The vial cap can be tightened, for example by twisting the vial cap, to fully engage the inner threaded segment of the vial cap with the syringe interface and the vial is sealed. By tightening the vial cap, the plug is lowered towards the adapter, and the vial assembly is disposed in the sealed configuration. Thus, in the sealed configuration, the stopper portion of the plug is fully engaged in the syringe interface, and the central body sits on the end of the syringe interface. 
     In some embodiments, the liquid dispensed in the vial is lyophilized Lyophilization can occur, for example, by freezing the liquid and exerting a vacuum pressure. The vial can then be sealed after lyophilization. The liquid can be lyophilized at any point after the liquid is dispensed in the vial and before sealing the vial. For example, in some embodiments, the liquid is lyophilized after dispensing the liquid in the vial and prior to attaching the adapter to the vial neck, after attaching the adapter to the vial neck and prior to attaching the vial cap to or placing the vial cap on the adapter, or after attaching the vial cap to or placing the vial cap on the adapter and before sealing the vial. 
     In some embodiments, a method of filling a vial assembly comprises dispensing a liquid into a vial comprising a vial body and a vial neck; attaching an adapter to the vial neck, said adapter comprising a top portion having a syringe interface, a bottom portion having a vial neck fitting, a gasket fitting within the vial neck fitting, and a longitudinally extending channel fluidly connecting the syringe interface to the vial neck; and sealing the vial by attaching a vial cap to the adapter, said vial cap having a central opening including a threaded segment that engages the syringe interface and a plug, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the vial cap. In some embodiments, the method further comprises fitting the gasket into the vial neck fitting. In some embodiments, the vial cap is attached to the adapter prior to attaching the adapter to the vial neck, and in some embodiments, the adapter is attached to the vial neck prior to attaching the vial cap to the adapter. In some embodiments, the liquid is dispensed into the vial prior to attaching the adapter to the vial neck, and in some embodiments, the adapter is attached to the vial neck prior to dispensing liquid into the vial. In some embodiments, the method further comprises lyophilizing the liquid (for example, by placing the vial cap on the adapter in an unsealed configuration, lyophilizing the liquid, and sealing the vial by tightening the vial cap after lyophilizing the liquid. In some embodiments, the syringe interface is a tapered conduit. In some embodiments, the syringe interface is a second threated segment on an outer surface of a conduit. In some embodiments, the syringe interface is a female luer. 
     In some embodiments, a method of filling a vial assembly comprises dispensing a liquid into a vial comprising a vial body and a vial neck; attaching an adapter to the vial neck, said adapter comprising a top portion having a syringe interface, a bottom portion having a vial neck fitting, a gasket fitting within the vial neck fitting, and a longitudinally extending channel fluidly connecting the syringe interface to the vial neck; and sealing the vial by attaching a vial cap to the adapter, said vial cap having a central opening including a threaded segment that engages the syringe interface and a coextruded plug, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the vial cap. In some embodiments, the method further comprises fitting the gasket into the vial neck fitting. In some embodiments, the vial cap is attached to the adapter prior to attaching the adapter to the vial neck, and in some embodiments, the adapter is attached to the vial neck prior to attaching the vial cap to the adapter. In some embodiments, the liquid is dispensed into the vial prior to attaching the adapter to the vial neck, and in some embodiments, the adapter is attached to the vial neck prior to dispensing liquid into the vial. In some embodiments, the method further comprises lyophilizing the liquid (for example, by placing the vial cap on the adapter in an unsealed configuration, lyophilizing the liquid, and sealing the vial by tightening the vial cap after lyophilizing the liquid. In some embodiments, the syringe interface is a tapered conduit. In some embodiments, the syringe interface is a second threated segment on an outer surface of a conduit. In some embodiments, the syringe interface is a female luer. 
     In some embodiments, a method of filling a vial assembly comprises dispensing a liquid into a vial comprising a vial body and a vial neck; attaching an adapter to the vial neck, said adapter comprising a top portion having a syringe interface, a bottom portion having a vial neck fitting, a gasket fitting within the vial neck fitting, and a longitudinally extending channel fluidly connecting the syringe interface to the vial neck; and sealing the vial by attaching a vial cap to the adapter, said vial cap having a central opening including a threaded segment that engages the syringe interface and a rim, said vial cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the vial neck, and an upper portion including a top portion defining a restraint coupled to a reduced diameter region defining an annulus, wherein the rim of the vial cap extends into the annulus to hold the plug in place. In some embodiments, the method further comprises fitting the gasket into the vial neck fitting. In some embodiments, the vial cap is attached to the adapter prior to attaching the adapter to the vial neck, and in some embodiments, the adapter is attached to the vial neck prior to attaching the vial cap to the adapter. In some embodiments, the liquid is dispensed into the vial prior to attaching the adapter to the vial neck, and in some embodiments, the adapter is attached to the vial neck prior to dispensing liquid into the vial. In some embodiments, the method further comprises lyophilizing the liquid (for example, by placing the vial cap on the adapter in an unsealed configuration, lyophilizing the liquid, and sealing the vial by tightening the vial cap after lyophilizing the liquid. In some embodiments, the syringe interface is a tapered conduit. In some embodiments, the syringe interface is a second threated segment on an outer surface of a conduit. In some embodiments, the syringe interface is a female luer. 
     In some embodiments, a method of filling a vial assembly comprises dispensing a liquid into a vial comprising a vial body and a vial neck; attaching an adapter to the vial neck, said adapter comprising a top portion having a syringe interface, a bottom portion having a vial neck fitting, a gasket fitting within the vial neck fitting, and a longitudinally extending channel fluidly connecting the syringe interface to the vial neck; and sealing the vial by attaching a vial cap to the adapter, said vial cap having a central opening including a threaded segment that engages the syringe interface and a rim, said vial cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the vial neck, a central body with a diameter wider than the lower stopper portion (the central body optionally including a plurality of compression ridges), and an upper portion including a top portion defining a restraint (which can have a domed surface or a beveled rim) coupled to a reduced diameter region defining an annulus, wherein the rim of the vial cap extends into the annulus to hold the plug in place. In some embodiments, the method further comprises fitting the gasket into the vial neck fitting. In some embodiments, the vial cap is attached to the adapter prior to attaching the adapter to the vial neck, and in some embodiments, the adapter is attached to the vial neck prior to attaching the vial cap to the adapter. In some embodiments, the liquid is dispensed into the vial prior to attaching the adapter to the vial neck, and in some embodiments, the adapter is attached to the vial neck prior to dispensing liquid into the vial. In some embodiments, the method further comprises lyophilizing the liquid (for example, by placing the vial cap on the adapter in an unsealed configuration, lyophilizing the liquid, and sealing the vial by tightening the vial cap after lyophilizing the liquid. In some embodiments, the syringe interface is a tapered conduit. In some embodiments, the syringe interface is a second threated segment on an outer surface of a conduit. In some embodiments, the syringe interface is a female luer. 
     In some embodiments, a method of filling a vial assembly comprises dispensing a liquid into a vial comprising a vial body and a vial neck; attaching an adapter to the vial neck, said adapter comprising a top portion having a syringe interface, a bottom portion having a vial neck fitting comprising a plurality of prongs comprising an anchor that engages an annular lip disposed on the vial neck, a gasket fitting within the vial neck fitting, and a longitudinally extending channel fluidly connecting the syringe interface to the vial neck; and sealing the vial by attaching a vial cap to the adapter, said vial cap having a central opening including a threaded segment that engages the syringe interface and a rim, said vial cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the vial neck, a central body with a diameter wider than the lower stopper portion (the central body optionally including a plurality of compression ridges), and an upper portion including a top portion defining a restraint (which can have a domed surface or a beveled rim) coupled to a reduced diameter region defining an annulus, wherein the rim of the vial cap extends into the annulus to hold the plug in place. In some embodiments, the method further comprises fitting the gasket into the vial neck fitting. In some embodiments, the vial cap is attached to the adapter prior to attaching the adapter to the vial neck, and in some embodiments, the adapter is attached to the vial neck prior to attaching the vial cap to the adapter. In some embodiments, the liquid is dispensed into the vial prior to attaching the adapter to the vial neck, and in some embodiments, the adapter is attached to the vial neck prior to dispensing liquid into the vial. In some embodiments, the method further comprises lyophilizing the liquid (for example, by placing the vial cap on the adapter in an unsealed configuration, lyophilizing the liquid, and sealing the vial by tightening the vial cap after lyophilizing the liquid. In some embodiments, the syringe interface is a tapered conduit. In some embodiments, the syringe interface is a second threated segment on an outer surface of a conduit. In some embodiments, the syringe interface is a female luer. 
     In some embodiments, a method of filling a vial assembly comprises dispensing a liquid into a vial comprising a vial body and a vial neck; fitting a gasket into an adapter, said adapter comprising a top portion having a syringe interface, a bottom portion having a vial neck fitting comprising a plurality of prongs comprising an anchor configured to engage an annular lip disposed on the vial neck, and a longitudinally extending channel fluidly connecting the syringe interface to the vial neck, wherein the gasket fits along an inner edge of the vial neck fitting and proximal to a lateral disk joining the plurality of prongs; attaching the adapter to the vial neck by engaging the anchor on the plurality of prongs with the annular lip; and sealing the vial by attaching a vial cap to the adapter, said vial cap having a central opening including a threaded segment that engages the syringe interface and a rim, said vial cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the vial neck, a central body with a diameter wider than the lower stopper portion (the central body optionally including a plurality of compression ridges), and an upper portion including a top portion defining a restraint (which can have a domed surface or a beveled rim) coupled to a reduced diameter region defining an annulus, wherein the rim of the vial cap extends into the annulus to hold the plug in place. In some embodiments, the method further comprises fitting the gasket into the vial neck fitting. In some embodiments, the vial cap is attached to the adapter prior to attaching the adapter to the vial neck, and in some embodiments, the adapter is attached to the vial neck prior to attaching the vial cap to the adapter. In some embodiments, the liquid is dispensed into the vial prior to attaching the adapter to the vial neck, and in some embodiments, the adapter is attached to the vial neck prior to dispensing liquid into the vial. In some embodiments, the method further comprises lyophilizing the liquid (for example, by placing the vial cap on the adapter in an unsealed configuration, lyophilizing the liquid, and sealing the vial by tightening the vial cap after lyophilizing the liquid. In some embodiments, the syringe interface is a tapered conduit. In some embodiments, the syringe interface is a second threated segment on an outer surface of a conduit. In some embodiments, the syringe interface is a female luer. 
     A user can fill a syringe by detaching (for example, by unscrewing) the vial cap from the adapter, attaching the syringe to the syringe interface of the vial neck, and drawing liquid contained within the vial into the syringe. In some embodiments, detaching the vial cap comprises severing a tamper-evident band. The syringe can comprise a male luer, which can interface with the syringe interface (which may comprise, for example, threading on the outer surface of the vial neck or a female luer). In some embodiments, the syringe is pre-filled with a liquid, and that liquid is dispensed into the vial after attaching the syringe to the vial neck. If a powder is contained within the vial, for example, the liquid from the pre-filled syringe can be used to suspend or dissolve the powder before the liquid is drawn into the syringe. In some embodiments, the vial contains a first liquid, and the syringe can be pre-filled with a second liquid. The second liquid can be dispensed into the vial and mix with the first liquid before the mixture is drawn from the vial by the syringe. 
     In some embodiments, a method of filling a syringe comprises detaching a vial cap (such as by unscrewing the vial cap) from a vial assembly comprising: a vial comprising a vial body and a vial neck; an adapter comprising a top portion having a syringe interface, a bottom portion having a vial neck fitting attached to the vial neck, and a channel fluidly connecting the syringe interface to the vial neck; a gasket disposed between the vial neck and the adapter; and the vial cap, said vial cap having a central opening including a threaded segment that engages the syringe interface and a plug, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the vial cap; attaching a syringe (which can include a male luer, such as a male luer lock or a male slip tip) to the syringe interface; and drawing a liquid contained within the vial into the syringe. In some embodiments, the method further comprises forming the liquid by adding a solution (which may be contained within the syringe) to the vial, and dissolving or suspending a lyophilized powder contained within the vial. In some embodiments, detaching the vial cap includes severing a tamper-evident band. In some embodiments, the syringe interface is a tapered conduit. In some embodiments, the syringe interface is a second threated segment on an outer surface of a conduit. In some embodiments, the syringe interface is a female luer. 
     In some embodiments, the method of filling a syringe comprises detaching a vial cap (such as by unscrewing the vial cap) from a vial assembly comprising: a vial comprising a vial body and a vial neck; an adapter comprising a top portion having a syringe interface, a bottom portion having a vial neck fitting attached to the vial neck, and a channel fluidly connecting the syringe interface to the vial neck; a gasket disposed between the vial neck and the adapter; and the vial cap, said vial cap having a central opening including a threaded segment that engages the syringe interface and a coextruded plug, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the vial cap; attaching a syringe (which can include a male luer, such as a male luer lock or a male slip tip) to the syringe interface; and drawing a liquid contained within the vial into the syringe. In some embodiments, the method further comprises forming the liquid by adding a solution (which may be contained within the syringe) to the vial, and dissolving or suspending a lyophilized powder contained within the vial. In some embodiments, detaching the vial cap includes severing a tamper-evident band. In some embodiments, the syringe interface is a tapered conduit. In some embodiments, the syringe interface is a second threated segment on an outer surface of a conduit. In some embodiments, the syringe interface is a female luer. 
     In some embodiments, a method of filling a syringe comprises detaching a vial cap (such as by unscrewing the vial cap) from a vial assembly comprising: a vial comprising a vial body and a vial neck; an adapter comprising a top portion having a syringe interface, a bottom portion having a vial neck fitting attached to the vial neck, and a channel fluidly connecting the syringe interface to the vial neck; a gasket disposed between the vial neck and the adapter; and the vial cap, said vial cap having a central opening including a threaded segment that engages the syringe interface and a rim, said vial cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the vial neck, and an upper portion including a top portion defining a restraint coupled to a reduced diameter region defining an annulus, wherein the rim of the vial cap extends into the annulus to hold the plug in place; attaching a syringe (which can include a male luer, such as a male luer lock or a male slip tip) to the syringe interface; and drawing a liquid contained within the vial into the syringe. In some embodiments, the method further comprises forming the liquid by adding a solution (which may be contained within the syringe) to the vial, and dissolving or suspending a lyophilized powder contained within the vial. In some embodiments, detaching the vial cap includes severing a tamper-evident band. In some embodiments, the syringe interface is a tapered conduit. In some embodiments, the syringe interface is a second threated segment on an outer surface of a conduit. In some embodiments, the syringe interface is a female luer. 
     In some embodiments, a method of filling a syringe comprises detaching a vial cap (such as by unscrewing the vial cap) from a vial assembly comprising: a vial comprising a vial body and a vial neck; an adapter comprising a top portion having a syringe interface, a bottom portion having a vial neck fitting attached to the vial neck, and a channel fluidly connecting the syringe interface to the vial neck; a gasket disposed between the vial neck and the adapter; and the vial cap, said vial cap having a central opening including a threaded segment that engages the syringe interface and a rim, said vial cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the vial neck, a central body with a diameter wider than the lower stopper portion (the central body optionally including a plurality of compression ridges), and an upper portion including a top portion defining a restraint (which can have a domed surface or a beveled rim) coupled to a reduced diameter region defining an annulus, wherein the rim of the vial cap extends into the annulus to hold the plug in place; attaching a syringe (which can include a male luer, such as a male luer lock or a male slip tip) to the syringe interface; and drawing a liquid contained within the vial into the syringe. In some embodiments, the method further comprises forming the liquid by adding a solution (which may be contained within the syringe) to the vial, and dissolving or suspending a lyophilized powder contained within the vial. In some embodiments, detaching the vial cap includes severing a tamper-evident band. In some embodiments, the syringe interface is a tapered conduit. In some embodiments, the syringe interface is a second threated segment on an outer surface of a conduit. In some embodiments, the syringe interface is a female luer. 
     In some embodiments, a method of filling a syringe comprises detaching a vial cap (such as by unscrewing the vial cap) from a vial assembly comprising: a vial comprising a vial body and a vial neck; an adapter comprising a top portion having a syringe interface, a bottom portion having a vial neck fitting comprising a plurality of prongs comprising an anchor that engages an annular lip disposed on the vial neck, and a channel fluidly connecting the syringe interface to the vial neck; a gasket disposed between the vial neck and the adapter; and the vial cap, said vial cap having a central opening including a threaded segment that engages the syringe interface and a rim, said vial cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the vial neck, a central body with a diameter wider than the lower stopper portion (the central body optionally including a plurality of compression ridges), and an upper portion including a top portion defining a restraint (which can have a domed surface or a beveled rim) coupled to a reduced diameter region defining an annulus, wherein the rim of the vial cap extends into the annulus to hold the plug in place; attaching a syringe (which can include a male luer, such as a male luer lock or a male slip tip) to the syringe interface; and drawing a liquid contained within the vial into the syringe. In some embodiments, the method further comprises forming the liquid by adding a solution (which may be contained within the syringe) to the vial, and dissolving or suspending a lyophilized powder contained within the vial. In some embodiments, detaching the vial cap includes severing a tamper-evident band. In some embodiments, the syringe interface is a tapered conduit. In some embodiments, the syringe interface is a second threated segment on an outer surface of a conduit. In some embodiments, the syringe interface is a female luer. 
     In some embodiments, a method of filling a syringe comprises detaching a vial cap (such as by unscrewing the vial cap) from a vial assembly comprising: a vial comprising a vial body and a vial neck; an adapter comprising a top portion having a syringe interface, a bottom portion having a vial neck fitting comprising a plurality of prongs comprising an anchor that engages an annular lip disposed on the vial neck, and a channel fluidly connecting the syringe interface to the vial neck; a gasket disposed along an inner edge of the vial neck fitting, proximal to a lateral disk joining the plurality of prongs, and proximal to an opening of the vial neck; and the vial cap, said vial cap having a central opening including a threaded segment that engages the syringe interface and a rim, said vial cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the vial neck, a central body with a diameter wider than the lower stopper portion (the central body optionally including a plurality of compression ridges), and an upper portion including a top portion defining a restraint (which can have a domed surface or a beveled rim) coupled to a reduced diameter region defining an annulus, wherein the rim of the vial cap extends into the annulus to hold the plug in place; attaching a syringe (which can include a male luer, such as a male luer lock or a male slip tip) to the syringe interface; and drawing a liquid contained within the vial into the syringe. In some embodiments, the method further comprises forming the liquid by adding a solution (which may be contained within the syringe) to the vial, and dissolving or suspending a lyophilized powder contained within the vial. In some embodiments, detaching the vial cap includes severing a tamper-evident band. In some embodiments, the syringe interface is a tapered conduit. In some embodiments, the syringe interface is a second threated segment on an outer surface of a conduit. In some embodiments, the syringe interface is a female luer. 
     In another aspect, there is provided a vial assembly comprising a vial having a vial body and a vial neck, the vial neck comprising an inner surface and an outer surface, the outer surface comprising an annular lip; and a vial cap having: a stopper having a top portion and a bottom portion, the top portion comprising a longitudinal aperture, and the bottom portion that fits into the vial neck; a conduit having a syringe interface at a first end and a barb at a second end, the second end fitting through the aperture in the stopper, and said barb engaging an underside of the top portion of the stopper; and an end cap having a central opening including a threaded segment that engages the syringe interface and a plug disposed therein, said plug having a lower stopper portion that fits within the syringe interface of the conduit and an upper portion that attaches to an upper portion of the end cap. In some embodiments, the stopper comprises a raised annular ridge around the aperture at the top of the stopper; and the end cap comprises a skirt that fits around the raised annular ridge. In some embodiments, the stopper comprises an annular lip that can sit on the annular lip disposed on the outside surface of the vial neck. In some embodiments, the bottom portion of the stopper comprises at least one truncated segment. In some embodiments, the syringe interface is a tapered conduit. In some embodiments, the syringe interface is a second threaded segment on an outer surface of a conduit. In some embodiments, the syringe interface is a female luer. In some embodiments, the vial assembly further comprises a ring that secures the stopper to the vial neck. In some embodiments, the vail assembly further comprises a tamper-evident band. 
     In some embodiments, the vial assembly comprises a vial having a vial body and a vial neck, the vial neck comprising an inner surface and an outer surface, the outer surface comprising an annular lip; and a vial cap having: a stopper having a top portion and a bottom portion, the top portion comprising a longitudinal aperture, and the bottom portion that fits into the vial neck; a conduit having a syringe interface at a first end and a barb at a second end, the second end fitting through the aperture in the stopper, and said barb engaging an underside of the top portion of the stopper; and an end cap having a central opening including a threaded segment that engages the syringe interface and a coextruded plug disposed therein, said plug having a lower stopper portion that fits within the syringe interface of the conduit and an upper portion that attaches to an upper portion of the end cap. In some embodiments, the stopper comprises a raised annular ridge around the aperture at the top of the stopper; and the end cap comprises a skirt that fits around the raised annular ridge. In some embodiments, the bottom portion of the stopper comprises at least one truncated segment. In some embodiments, the stopper comprises an annular lip that can sit on the annular lip disposed on the outside surface of the vial neck. In some embodiments, the syringe interface is a tapered conduit. In some embodiments, the syringe interface is a second threaded segment on an outer surface of a conduit. In some embodiments, the syringe interface is a female luer. In some embodiments, the vial assembly further comprises a ring that secures the stopper to the vial neck. In some embodiments, the vail assembly further comprises a tamper-evident band. 
     In some embodiments, the vial assembly comprises a vial having a vial body and a vial neck, the vial neck comprising an inner surface and an outer surface, the outer surface comprising an annular lip; and a vial cap having: a stopper having a top portion and a bottom portion, the top portion comprising a longitudinal aperture, and the bottom portion that fits into the vial neck; a conduit having a syringe interface at a first end and a barb at a second end, the second end fitting through the aperture in the stopper, and said barb engaging an underside of the top portion of the stopper; and an end cap having a central opening including a threaded segment that engages the syringe interface and a rim, said end cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the syringe interface of the conduit and an upper portion including a top portion defining a restraint coupled to a reduced diameter region defining an annulus, wherein the rim of the end cap extends into the annulus to hold the plug in place. In some embodiments, the stopper comprises a raised annular ridge around the aperture at the top of the stopper; and the end cap comprises a skirt that fits around the raised annular ridge. In some embodiments, the stopper comprises an annular lip that can sit on the annular lip disposed on the outside surface of the vial neck. In some embodiments, the bottom portion of the stopper comprises at least one truncated segment. In some embodiments, the syringe interface is a tapered conduit. In some embodiments, the syringe interface is a second threaded segment on an outer surface of a conduit. In some embodiments, the syringe interface is a female luer. In some embodiments, the vial assembly further comprises a ring that secures the stopper to the vial neck. In some embodiments, the vail assembly further comprises a tamper-evident band. 
     In some embodiments, the vial assembly comprises a vial having a vial body and a vial neck, the vial neck comprising an inner surface and an outer surface, the outer surface comprising an annular lip; and a vial cap having: a stopper having a top portion and a bottom portion, the top portion comprising a longitudinal aperture, and the bottom portion that fits into the vial neck; a conduit having a syringe interface at a first end and a barb at a second end, the second end fitting through the aperture in the stopper, and said barb engaging an underside of the top portion of the stopper; and an end cap having a central opening including a threaded segment that engages the syringe interface and a rim, said end cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the syringe interface of the conduit, a central body with a diameter wider than the lower stopper portion (the central body optionally including a plurality of compression ridges), and an upper portion including a top portion defining a restraint (which can optionally have a domed surface or a beveled rim) coupled to a reduced diameter region defining an annulus, wherein the rim of the end cap extends into the annulus to hold the plug in place. In some embodiments, the stopper comprises a raised annular ridge around the aperture at the top of the stopper; and the end cap comprises a skirt that fits around the raised annular ridge. In some embodiments, the stopper comprises an annular lip that can sit on the annular lip disposed on the outside surface of the vial neck. In some embodiments, the bottom portion of the stopper comprises at least one truncated segment. In some embodiments, the syringe interface is a tapered conduit. In some embodiments, the syringe interface is a second threaded segment on an outer surface of a conduit. In some embodiments, the syringe interface is a female luer. In some embodiments, the vial assembly further comprises a ring that secures the stopper to the vial neck. In some embodiments, the vail assembly further comprises a tamper-evident band. 
       FIG. 6A  illustrates an exemplary embodiment of a vial assembly comprising a vial and a vial cap comprising a stopper, a conduit, and an end cap, along with a cross-sectional view of the vial assembly.  FIG. 6B  illustrates a close-up view of the vial cap components (stopper, conduit, and end cap), the vial cap with the components pre-assembled, and a cross-sectional view of each. The vial  600  comprises a vial body  602  and a vial neck  604 . An annular lip  606  is disposed on the outer surface of the vial neck  604 . The vial can contain a liquid or powder  608  (for example, a liquid that has been lyophilized), such as a mediation. The vial cap includes a stopper  610 , a conduit  612 , and an end cap  614 . 
     The stopper  610  has a top portion  616 , which includes a longitudinal aperture  618  (for example, in the center of the top portion  616 ), and a bottom portion  620 , which can fit into the vial neck  604 . The stopper has an annular lip  622  around the top portion  616  of the stopper  610 . Once the bottom portion  620  of the stopper  610  is fitted into the vial neck  604 , the annular lip  622  can sit on the annular lip  606  on the outer surface of the vial neck  604 . Optionally, the stopper  610  has a raised annular ridge  624  around the longitudinal aperture  618 . In some embodiments, the bottom potion  620  of the stopper  620  comprises one or more elongated sections  626  and one or more truncated sections  628 . Having one or more elongated sections and one or more truncated section on the bottom portion of the stopper can be useful when lyophilizing a liquid that is contained within the vial. For example, liquid can be dispensed in the vial and the vial cap partially inserted into the vial neck such that the elongated portions are within the vial neck and the truncated sections are outside of the vial neck. This unsealed configuration produces a gap in the seal formed by the elongated sections of the stopper with the vial neck such that the liquid contained within the vial is fluidly connected to the atmosphere. Lyophilization allows for the sublimed or evaporated fluid to flow out of the vial through the gap in the seal.  FIG. 6C  illustrates a vial assembly with a vial cap comprising a stopper partially inserted into a vial neck (i.e., in an unsealed configuration). The stopper has a truncated section and an elongated section, and a gap is formed between the end of the vial neck and the truncated section. Once the liquid has been lyophilized, the bottom portion of the stopper can be fully inserted into the vial neck, thereby sealing the vial (i.e., the vial cap is in a sealed configuration).  FIG. 6D  illustrates cross-sectional views of the vial assembly in the sealed configuration and the unsealed configuration. 
     Referring back to  FIG. 6B , the conduit comprises a syringe interface  630  at one end and a barb  632  at the other end. The barb  632  can be, for example, a hose barb or a lateral prong. The syringe interface  630  is configured to engage a threated interior portion  634  of the end cap  614 . The syringe interface  630  can be, for example, a conduit with a threaded outer surface or a female luer lock (as illustrated in  FIG. 6B ). The syringe interface  630  can also interface with a male luer lock or slip tip (for example, on a syringe). In some embodiments, the inner portion of the syringe interface  630  is tapered (that is, the syringe interface has an inner diameter proximal to the barb  632  that is narrower than the distal inner diameter). The end of the conduit  612  having the barb  632  is inserted into the aperture  618  of the stopper  610 . Once the conduit  612  is inserted into the aperture  618  of the stopper  610 , the barb  632  limits withdrawal of the conduit  612 . The base  636  of the conduit  612  is wider than the aperture  618  to prevent the conduit  612  from falling through the aperture  618 . In some embodiments, for example if the stopper  610  has a raised annular ridge  624  around the aperture  618 , the base  636  of the conduit  612  is smaller than the inner diameter of the raised annular ridge  624 . Optionally, the inner surface of the raised annular ridge  624  includes a plurality of ribs  638  and the base  636  of the conduit  612  includes a plurality of ribs  640 . The combination of the plurality of ribs  638  on the inner surface of the raised annular ridge  624  and the plurality of ribs  640  on the base  636  of the conduit  612  limits rotation of the conduit  612  once inserted into the stopper  610 . 
     The end cap  614  includes a central opening including a threaded interior portion  634  that engages the syringe interface  630 . In some embodiments, the end cap  614  comprises a coextruded plug  642  directed toward the threaded interior portion  634  of the end cap  614 , which can be attached to the upper region of the interior of the end cap  614 . The plug  642  can fit into the syringe interface  630  of the conduit  612 . In some embodiments, the plug  642  is tapered, which can provide a better seal if the inner surface of the syringe interface is tapered. Optionally, a skirt  644  is disposed around the bottom of the end cap  614 . The skirt  644  can fit around the outer surface of the raised annular ridge  624  of the stopper  610 . Also optionally, the outer surface of the end cap  614  includes a plurality of longitudinally disposed ribs  646 , which can help provide traction when opening or closing the vial assembly. 
     The vial cap is assembled by inserting the conduit  612  into the aperture  618  of the stopper  610 . The end cap  614  is then attached, for example by screwing the end cap  614  to the syringe interface  630  by engaging the threaded segment  634  of the end cap  614  with the syringe interface. The vial  600  can be sealed by attaching the vial cap to the vial neck  604 . For example, the bottom portion  620  of the stopper  610  can be inserted into the vial neck  604 . Once the vial cap is attached the vial neck, a ring  648  (which can be, for example, metal, a polymer, or rubber) can be attached to the vial assembly by wrapping the annular lip  622  of the stopper  610  and the annular lip  606  on the outer surface of the vial neck  604 . The ring  648  secures the stopper  610  to the vial neck  604 , as illustrated in  FIG. 6A . 
     In some embodiments, the vial assembly includes a tamper-evident band ( FIG. 6E ). For example, the end cap  614  can comprise a tamper-evident band  650  (which may extend from the skirt  644 ) that covers a portion of the annular lip  622  of the stopper  610 . The ring  648  can wrap around the outer portion of the tamper-evident band, the annular lip  622  of the stopper, and the annular lip  606  on the outer surface of the vial neck. The tamper-evident band  650  can be attached to the rest of the end cap (such as to the skirt  644 ) by a perforated segment  652 . When the end cap  614  is separated from the rest of the vial assembly, the ring  648  retains the tamper-evident band  650  and the perforate segment  652  is torn, thereby separating the tamper-evident band  650  from the end cap  614 . This separation indicates that the end cap  614  has been opened. 
     The vial assembly can be filled by dispensing a liquid into a vial comprising a vial body and a vial neck the vial neck; and sealing the vial by attaching a vial cap to the vial neck, the vial cap having a stopper comprising a top portion and a bottom portion, the top portion having a longitudinal aperture, and the bottom portion fitting into the vial neck; a conduit having a syringe interface at a first end and a barb at a second end, the second end fitting through the aperture in the stopper; and an end cap comprising a threaded interior portion that engages the syringe interface. 
     The vial cap can be assembled by attaching the conduit to the end cap on the end of the conduit having the syringe interface, and attaching the conduit to the stopper on the end of the conduit having the barb. In some embodiments, the conduit is attached to the end cap prior to attaching the conduit to the stopper. In other embodiments, the conduit is attached to the stopper prior to attaching the conduit to the end cap. In some embodiments, the vial cap is pre-assembled. 
     After liquid has been dispensed in the vial, the vial cap can then be attached to the adapter in either a sealed configuration or an unsealed configuration. For example, the bottom portion of the stopper can have one or more elongated segments and one or more truncated segments. The bottom portion of the stopper can be inserted into the vial neck such that the elongated segments are within the vial neck and the truncated segments are not within the vial neck, thereby forming a gap (i.e., the vial cap is attached to the vial neck in an unsealed configuration). The bottom portion of the stopper then be fully inserted into the vial neck such that both one or more elongated segments and the one or more truncated segments are within the vial neck, and the vial is sealed (i.e., the vial cap is attached to the vial neck in a sealed configuration). 
     Optionally, the liquid dispensed in the vial is lyophilized Lyophilization can occur, for example, by freezing the liquid and exerting a vacuum pressure. The vial can then be sealed after lyophilization. The liquid can be lyophilized at any point after the liquid is dispensed in the vial and before sealing the vial. For example, in some embodiments, the liquid is lyophilized after dispensing the liquid in the vial and prior to attaching the vial cap to the vial neck, or after attaching the vial cap to the vial neck in an unsealed configuration and prior to sealing the vial. By lyophilizing the liquid in the vial when the vial cap is in the unsealed configuration (as opposed to prior to attaching the vial cap), the risk of contamination of the liquid dispensed into the vial is minimized. 
     In some embodiments, a method of filing a vial assembly comprises dispensing a liquid into a vial comprising a vial body and a vial neck the vial neck; and sealing the vial by attaching a vial cap to the vial neck, the vial cap having: a stopper having a top portion and a bottom portion, the top portion comprising a longitudinal aperture, and the bottom portion that fits into the vial neck; a conduit having a syringe interface at a first end and a barb at a second end, the second end fitting through the aperture in the stopper, and said barb engaging an underside of top portion of the stopper; and an end cap having a central opening including a threaded segment that engages the syringe interface and a plug disposed in the central opening, said plug having a lower stopper portion that fits within the syringe interface of the conduit and an upper portion that attaches to an upper portion of the end cap. In some embodiments, the method further comprises attaching the end cap to the conduit. In some embodiments, the method further comprises attaching the conduit to the stopper. In some embodiments, the vial cap is pre-assembled. In some embodiments, the stopper includes an annular lip that sits on an annular lip disposed on the outer surface of the vial neck and the method further includes attaching a ring around the annular lip of the stopper and the annular lip of the vial neck, thereby securing the stopper to the vial neck. In some embodiments, the stopper comprises at least one truncated segment. In some embodiments, the method further comprises lyophilizing the liquid (for example, by partially inserting the stopper in the vial neck such that a gap is formed between the vial neck and the truncated segment of the bottom portion of the stopper, lyophilizing the liquid, and sealing the vial by fully inserting the bottom portion of the stopper into the vial neck). 
     In some embodiments, a method of filing a vial assembly comprises dispensing a liquid into a vial comprising a vial body and a vial neck the vial neck; and sealing the vial by attaching a vial cap to the vial neck, the vial cap having: a stopper having a top portion and a bottom portion, the top portion comprising a longitudinal aperture, and the bottom portion that fits into the vial neck; a conduit having a syringe interface at a first end and a barb at a second end, the second end fitting through the aperture in the stopper, and said barb engaging an underside of top portion of the stopper; and an end cap having a central opening including a threaded segment that engages the syringe interface and a coextruded plug disposed in the central opening, said plug having a lower stopper portion that fits within the syringe interface of the conduit and an upper portion that attaches to an upper portion of the end cap. In some embodiments, the method further comprises attaching the end cap to the conduit. In some embodiments, the method further comprises attaching the conduit to the stopper. In some embodiments, the vial cap is pre-assembled. In some embodiments, the stopper includes an annular lip that sits on an annular lip disposed on the outer surface of the vial neck and the method further includes attaching a ring around the annular lip of the stopper and the annular lip of the vial neck, thereby securing the stopper to the vial neck. In some embodiments, the stopper comprises at least one truncated segment. In some embodiments, the method further comprises lyophilizing the liquid (for example, by partially inserting the stopper in the vial neck such that a gap is formed between the vial neck and the truncated segment of the bottom portion of the stopper, lyophilizing the liquid, and sealing the vial by fully inserting the bottom portion of the stopper into the vial neck). 
     In some embodiments, a method of filing a vial assembly comprises dispensing a liquid into a vial comprising a vial body and a vial neck the vial neck; and sealing the vial by attaching a vial cap to the vial neck, the vial cap having: a stopper having a top portion and a bottom portion, the top portion comprising a longitudinal aperture, and the bottom portion that fits into the vial neck; a conduit having a syringe interface at a first end and a barb at a second end, the second end fitting through the aperture in the stopper, and said barb engaging an underside of top portion of the stopper; and an end cap having a central opening including a threaded segment that engages the syringe interface and a rim, said end cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the syringe interface of the conduit and an upper portion including a top portion defining a restraint coupled to a reduced diameter region defining an annulus, wherein the rim of the end cap extends into the annulus to hold the plug in place. In some embodiments, the method further comprises attaching the end cap to the conduit. In some embodiments, the method further comprises attaching the conduit to the stopper. In some embodiments, the vial cap is pre-assembled. In some embodiments, the stopper includes an annular lip that sits on an annular lip disposed on the outer surface of the vial neck and the method further includes attaching a ring around the annular lip of the stopper and the annular lip of the vial neck, thereby securing the stopper to the vial neck. In some embodiments, the stopper comprises at least one truncated segment. In some embodiments, the method further comprises lyophilizing the liquid (for example, by partially inserting the stopper in the vial neck such that a gap is formed between the vial neck and the truncated segment of the bottom portion of the stopper, lyophilizing the liquid, and sealing the vial by fully inserting the bottom portion of the stopper into the vial neck). 
     In some embodiments, a method of filing a vial assembly comprises dispensing a liquid into a vial comprising a vial body and a vial neck the vial neck; and sealing the vial by attaching a vial cap to the vial neck, the vial cap having: a stopper having a top portion and a bottom portion, the top portion comprising a longitudinal aperture, and the bottom portion that fits into the vial neck; a conduit having a syringe interface at a first end and a barb at a second end, the second end fitting through the aperture in the stopper, and said barb engaging an underside of top portion of the stopper; and an end cap having a central opening including a threaded segment that engages the syringe interface and a rim, said end cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the syringe interface of the conduit, a central body with a diameter wider than the lower stopper portion (the central body optionally including a plurality of compression ridges), and an upper portion including a top portion defining a restraint (which can optionally have a domed surface or a beveled rim) coupled to a reduced diameter region defining an annulus, wherein the rim of the end cap extends into the annulus to hold the plug in place. In some embodiments, the method further comprises attaching the end cap to the conduit. In some embodiments, the method further comprises attaching the conduit to the stopper. In some embodiments, the vial cap is pre-assembled. In some embodiments, the stopper includes an annular lip that sits on an annular lip disposed on the outer surface of the vial neck and the method further includes attaching a ring around the annular lip of the stopper and the annular lip of the vial neck, thereby securing the stopper to the vial neck. In some embodiments, the stopper comprises at least one truncated segment. In some embodiments, the method further comprises lyophilizing the liquid (for example, by partially inserting the stopper in the vial neck such that a gap is formed between the vial neck and the truncated segment of the bottom portion of the stopper, lyophilizing the liquid, and sealing the vial by fully inserting the bottom portion of the stopper into the vial neck). 
     A user can fill a syringe by detaching (for example, by unscrewing) the end cap from the conduit, attaching the syringe to the syringe interface of the conduit, and drawing liquid contained within the vial into the syringe. In some embodiments, detaching the end cap comprises severing a tamper-evident band. The syringe can comprise a male luer, which can interface with the syringe interface (which may comprise, for example, threading on the outer surface of the vial neck or a female luer). In some embodiments, the syringe is pre-filled with a liquid, and that liquid is dispensed into the vial after attaching the syringe to the syringe interface of the conduit. If a powder is contained within the vial, for example, the liquid from the pre-filled syringe can be used to suspend or dissolve the powder before the liquid is drawn into the syringe. In some embodiments, the vial contains a first liquid, and the syringe can be pre-filled with a second liquid. The second liquid can be dispensed into the vial and mix with the first liquid before the mixture is drawn from the vial by the syringe. 
     In some embodiments, a method of filling a syringe comprises detaching an end cap from a vial assembly (for example, by unscrewing the end cap), said vial assembly comprising: a vial having a vial body and a vial neck, the vial neck having an inner surface and an outer surface, the outer surface having an annular lip; and a vial cap having a stopper having a top portion and a bottom portion, the top portion comprising a longitudinal aperture, and the bottom portion that fits into the vial neck; a conduit having a syringe interface at a first end and a barb at a second end, the second end fitting through the aperture in the stopper, and said barb engaging an underside of top portion of the stopper; and the end cap; said end cap having a central opening including a threaded segment that engages the syringe interface and a plug disposed in the central opening, said plug having a lower stopper portion that fits within the syringe interface of the conduit and an upper portion that attaches to an upper portion of the end cap; attaching a syringe to the syringe interface (which can comprise a male luer, such as a male luer lock or a male luer slip); and drawing a liquid contained within the vial into the syringe. In some embodiments, the method further includes forming the liquid by adding a solution to the vial (which may be contained within the syringe), and dissolving or suspending a lyophilized powder contained within the vial. 
     In some embodiments, a method of filling a syringe comprises detaching an end cap from a vial assembly (for example, by unscrewing the end cap), said vial assembly comprising: a vial having a vial body and a vial neck, the vial neck having an inner surface and an outer surface, the outer surface having an annular lip; and a vial cap having a stopper having a top portion and a bottom portion, the top portion comprising a longitudinal aperture, and the bottom portion that fits into the vial neck; a conduit having a syringe interface at a first end and a barb at a second end, the second end fitting through the aperture in the stopper, and said barb engaging an underside of top portion of the stopper; and the end cap; said end cap having a central opening including a threaded segment that engages the syringe interface and a coextruded plug disposed in the central opening, said plug having a lower stopper portion that fits within the syringe interface of the conduit and an upper portion that attaches to an upper portion of the end cap; attaching a syringe to the syringe interface (which can comprise a male luer, such as a male luer lock or a male luer slip); and drawing a liquid contained within the vial into the syringe. In some embodiments, the method further includes forming the liquid by adding a solution to the vial (which may be contained within the syringe), and dissolving or suspending a lyophilized powder contained within the vial. 
     In some embodiments, a method of filling a syringe comprises detaching an end cap from a vial assembly (for example, by unscrewing the end cap), said vial assembly comprising: a vial having a vial body and a vial neck, the vial neck having an inner surface and an outer surface, the outer surface having an annular lip; and a vial cap having a stopper having a top portion and a bottom portion, the top portion comprising a longitudinal aperture, and the bottom portion that fits into the vial neck; a conduit having a syringe interface at a first end and a barb at a second end, the second end fitting through the aperture in the stopper, and said barb engaging an underside of top portion of the stopper; and the end cap; said end cap having a central opening including a threaded segment that engages the syringe interface and a rim, and said end cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the syringe interface of the conduit and an upper portion including a top portion defining a restraint coupled to a reduced diameter region defining an annulus, wherein the rim of the end cap extends into the annulus to hold the plug in place; attaching a syringe to the syringe interface (which can comprise a male luer, such as a male luer lock or a male luer slip); and drawing a liquid contained within the vial into the syringe. In some embodiments, the method further includes forming the liquid by adding a solution to the vial (which may be contained within the syringe), and dissolving or suspending a lyophilized powder contained within the vial. 
     In some embodiments, a method of filling a syringe comprises detaching an end cap from a vial assembly (for example, by unscrewing the end cap), said vial assembly comprising: a vial having a vial body and a vial neck, the vial neck having an inner surface and an outer surface, the outer surface having an annular lip; and a vial cap having a stopper having a top portion and a bottom portion, the top portion comprising a longitudinal aperture, and the bottom portion that fits into the vial neck; a conduit having a syringe interface at a first end and a barb at a second end, the second end fitting through the aperture in the stopper, and said barb engaging an underside of top portion of the stopper; and the end cap; said end cap having a central opening including a threaded segment that engages the syringe interface and a rim, and said end cap carrying a plug in the central opening, said plug having a lower stopper portion that fits within the syringe interface of the conduit, a central body with a diameter wider than the lower stopper portion (the central body optionally including a plurality of compression ridges), and an upper portion including a top portion defining a restraint (which can optionally have a domed surface or a beveled rim) coupled to a reduced diameter region defining an annulus, wherein the rim of the end cap extends into the annulus to hold the plug in place; attaching a syringe to the syringe interface (which can comprise a male luer, such as a male luer lock or a male luer slip); and drawing a liquid contained within the vial into the syringe. In some embodiments, the method further includes forming the liquid by adding a solution to the vial (which may be contained within the syringe), and dissolving or suspending a lyophilized powder contained within the vial. 
     Features and preferences described above in relation to “embodiments” are distinct preferences and are not limited only to that particular embodiment; they may be freely combined with features from other embodiments, where technically feasible, and may form preferred combinations of features. 
     The description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements. Various modifications to the described embodiments will be readily apparent to those persons skilled in the art and the generic principles herein may be applied to other embodiments. Thus, the present invention is not intended to be limited to the embodiment shown but is to be accorded the widest scope consistent with the principles and features described herein. 
     EXEMPLARY EMBODIMENTS 
     The following embodiments are exemplary and are not intended to limit the scope of the invention. 
     Embodiment 1 
     A vial assembly comprising: 
     a vial comprising a vial body and a vial neck, the vial neck having a syringe interface; and 
     a vial cap having a central opening including a threaded segment that engages the syringe interface and a plug, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the vial cap. 
     Embodiment 2 
     The vial assembly of embodiment 1, wherein the vial cap and the plug are coextruded. 
     Embodiment 3 
     The vial assembly of embodiment 1, the vial cap further including a rim, the upper portion of the plug including a top portion defining a restraint coupled to a reduced diameter region defining an annulus, wherein the rim of the vial cap extends into the annulus to hold the plug in place. 
     Embodiment 4 
     The vial assembly of embodiment 3, wherein the plug further includes a central body with a diameter wider than the lower stopper portion. 
     Embodiment 5 
     The vial assembly of embodiment 4, wherein the central body of the plug comprises a plurality of lateral compression ridges. 
     Embodiment 6 
     The vial assembly of any one of embodiments 3-5, wherein the restraint comprises a domed surface. 
     Embodiment 7 
     The vial assembly of any one of embodiments 3-5, wherein the restraint comprises a beveled rim. 
     Embodiment 8 
     The vial assembly of any one of embodiments 3-7, wherein the rim that extends into the annulus of the plug comprises an angled inner surface. 
     Embodiment 9 
     The vial assembly of any one of embodiments 3-8, wherein the rim that extends into the annulus of the plug is formed by an aperture on a top surface of the vial cap. 
     Embodiment 10 
     The vial assembly of any one of embodiments 3-8, wherein the rim that extends into the annulus of the plug protrudes into the central opening of the vial cap. 
     Embodiment 11 
     A vial assembly comprising: 
     a vial comprising a vial body and a vial neck, the vial neck having a syringe interface; and 
     a vial cap comprising a first component and a second component, said first component having an internal threaded segment that engages the syringe interface and an outer surface comprising a plurality of longitudinally extending ribs separated by a plurality of longitudinally extending channels, said second component including a plurality of longitudinally extending prongs that engage with a surface in the channels on the outer surface of the first component, said second component further including a central opening formed by the plurality of longitudinally extending prongs, and a plug disposed in the central opening, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the second component. 
     Embodiment 12 
     The vial assembly of embodiment 11, wherein the second component and the plug are coextruded. 
     Embodiment 13 
     The vial assembly of embodiment 11, wherein the second component further includes a rim, wherein the upper portion of the plug includes a top portion defining a restraint coupled to a reduced diameter region defining an annulus, and wherein the rim of the second component extends into the annulus to hold the plug in place. 
     Embodiment 14 
     The vial assembly of embodiment 13, wherein the plug further includes a central body with a diameter wider than the lower stopper portion. 
     Embodiment 15 
     The vial assembly of embodiment 14, wherein the central body of the plug comprises a plurality of lateral compression ridges. 
     Embodiment 16 
     The vial assembly of any one of embodiments 13-15, wherein the restraint comprises a domed surface. 
     Embodiment 17 
     The vial assembly of any one of embodiments 13-15, wherein the restraint comprises a beveled rim. 
     Embodiment 18 
     The vial assembly of any one of embodiments 13-17, wherein the rim that extends into the annulus of the plug comprises an angled inner surface. 
     Embodiment 19 
     The vial assembly of any one of embodiments 13-18, wherein the rim that extends into the annulus of the plug is formed by an aperture on a top surface of the vial cap. 
     Embodiment 20 
     The vial assembly of any one of embodiments 13-18, wherein the rim that extends into the annulus of the plug protrudes into the central opening of the vial cap. 
     Embodiment 21 
     The vial assembly of any one of embodiments 11-20, wherein at least one of the prongs in the plurality of longitudinally extending prongs comprises an anchor that engages a counter-anchor disposed in a channel in the plurality of longitudinally extending channels. 
     Embodiment 22 
     The vial assembly of any one of embodiments 1-21, wherein the vial neck is tapered. 
     Embodiment 23 
     The vial assembly of any one of embodiments 1-22, wherein the syringe interface is a second threaded segment on an outer surface of the vial neck. 
     Embodiment 24 
     The vial assembly of any one of embodiments 1-22, wherein the syringe interface is a female luer. 
     Embodiment 25 
     The vial assembly of any one of embodiments 1-24, wherein the stopper portion of the plug forms a seal with the inner surface of the vial neck. 
     Embodiment 26 
     The vial assembly of any one of embodiments 1-25, wherein the vial assembly comprises a tamper-evident band. 
     Embodiment 27 
     The vial assembly of embodiment 26, wherein the vial comprises an annular lip disposed on the outer surface of the vial neck; the tamper-evident band is attached to the vial cap; and the annular lip disposed on the outer surface of the vial neck secures the tamper-evident band to the vial. 
     Embodiment 28 
     The vial assembly of any one of embodiments 1-27, wherein the vial body has an open base. 
     Embodiment 29 
     The vial assembly of any one of embodiments 1-27, wherein the vial body includes a base that is sealed with a thermoformed plastic or foil. 
     Embodiment 30 
     A vial assembly comprising: 
     a vial having a vial body and a vial neck; 
     an adapter having a top portion having a syringe interface, a bottom portion having a vial neck fitting attached to the vial neck, and a channel fluidly connecting the syringe interface to the vial neck; 
     a gasket disposed between the vial neck and the adapter; and 
     a vial cap having a central opening including a threaded segment that engages the syringe interface and a plug, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the vial cap. 
     Embodiment 31 
     The vial assembly of embodiment 30, wherein the vial cap and the plug are coextruded. 
     Embodiment 32 
     The vial assembly of embodiment 30, the vial cap further including a rim, the upper portion of the plug including a top portion defining a restraint coupled to a reduced diameter region defining an annulus, wherein the rim of the vial cap extends into the annulus to hold the plug in place. 
     Embodiment 33 
     The vial assembly of embodiment 32, wherein the plug further includes a central body with a diameter wider than the lower stopper portion. 
     Embodiment 34 
     The vial assembly of embodiment 33, wherein the central body of the plug comprises a plurality of lateral compression ridges. 
     Embodiment 35 
     The vial assembly of any one of embodiments 32-34, wherein the restraint comprises a domed surface. 
     Embodiment 36 
     The vial assembly of any one of embodiments 32-34, wherein the restraint comprises a beveled rim. 
     Embodiment 37 
     The vial assembly of any one of embodiments 32-36, wherein the rim that extends into the annulus of the plug comprises an angled inner surface. 
     Embodiment 38 
     The vial assembly of any one of embodiments 32-37, wherein the rim that extends into the annulus of the plug is formed by an aperture on a top surface of the vial cap. 
     Embodiment 39 
     The vial assembly of any one of embodiments 32-37, wherein the rim that extends into the annulus of the plug protrudes into the central opening of the vial cap. 
     Embodiment 40 
     The vial assembly of any one of embodiments 30-39, wherein the vial cap comprises a skirt that surrounds a portion of the vial neck fitting of the adapter. 
     Embodiment 41 
     The vial assembly of any one of embodiments 30-40, wherein the syringe interface is a tapered conduit. 
     Embodiment 42 
     The vial assembly of any one of embodiments 30-41 wherein the syringe interface is a second threaded segment on an outer surface of a conduit. 
     Embodiment 43 
     The vial assembly of any one of embodiments 30-42, wherein the syringe interface is a female luer. 
     Embodiment 44 
     The vial assembly of any one of embodiments 30-43, wherein the vial neck fitting comprises a plurality of prongs that comprise an anchor that engages an annular lip on the vial neck. 
     Embodiment 45 
     The vial assembly of any one of embodiments 30-44, wherein the vial cap comprises an outer surface comprising a plurality of longitudinally extending ribs. 
     Embodiment 46 
     The vial assembly of any one of embodiments 30-45, wherein the vial assembly comprises a tamper-evident band. 
     Embodiment 47 
     The vial assembly of embodiment 46, wherein the vial cap comprises a skirt that surrounds a portion of the vial neck fitting of the adapter; 
     the tamper-evident band is attached to the skirt; and 
     the adapter secures the tamper-evident band to the vial. 
     Embodiment 48 
     A vial assembly comprising: 
     a vial having a vial body and a vial neck, the vial neck comprising an inner surface and an outer surface, the outer surface comprising an annular lip; and 
     a vial cap having: 
     a stopper having a top portion and a bottom portion, the top portion comprising a longitudinal aperture, and the bottom portion that fits into the vial neck; 
     a conduit having a syringe interface at a first end and a barb at a second end, the second end fitting through the aperture in the stopper, and said barb engaging an underside of the top portion of the stopper; and 
     an end cap having a central opening including a threaded segment that engages the syringe interface and a plug disposed in the central opening, said plug having a lower stopper portion that fits within the syringe interface of the conduit and an upper portion that attaches to an upper portion of the end cap. 
     Embodiment 49 
     The vial assembly of embodiment 48, wherein the end cap and the plug are coextruded. 
     Embodiment 50 
     The vial assembly of embodiment 48, wherein the end cap further includes a rim, wherein the upper portion of the plug includes a top portion defining a restraint coupled to a reduced diameter region defining an annulus, and wherein the rim of the end cap extends into the annulus to hold the plug in place. 
     Embodiment 51 
     The vial assembly of embodiment 50, wherein the plug further includes a central body with a diameter wider than the lower stopper portion. 
     Embodiment 52 
     The vial assembly of embodiment 51, wherein the central body of the plug comprises a plurality of lateral compression ridges. 
     Embodiment 53 
     The vial assembly of any one of embodiments 50-52, wherein the restraint comprises a domed surface. 
     Embodiment 54 
     The vial assembly of any one of embodiments 50-52, wherein the restraint comprises a beveled rim. 
     Embodiment 55 
     The vial assembly of any one of embodiments 50-54, wherein the rim that extends into the annulus of the plug comprises an angled inner surface. 
     Embodiment 56 
     The vial assembly of any one of embodiments 50-55, wherein the rim that extends into the annulus of the plug is formed by an aperture on a top surface of the vial cap. 
     Embodiment 57 
     The vial assembly of any one of embodiments 50-56, wherein the rim that extends into the annulus of the plug protrudes into the central opening of the vial cap. 
     Embodiment 58 
     The vial assembly of any one of embodiments 48-57, wherein the syringe interface is tapered. 
     Embodiment 59 
     The vial assembly of any one of embodiments 48-58, wherein the syringe interface is a second threaded segment on an outer surface of the syringe interface. 
     Embodiment 60 
     The vial assembly of any one of embodiments 48-58, wherein the syringe interface is a female luer. 
     Embodiment 61 
     The vial assembly of any one of embodiments 48-60, wherein: 
     the stopper comprises a raised annular ridge around the aperture at the top of the stopper; and 
     the end cap comprises a skirt that fits around the raised annular ridge. 
     Embodiment 62 
     The vial assembly of any one of embodiments 48-61, wherein the stopper comprises an annular lip that sits on the annular lip disposed on an outer surface of the vial neck. 
     Embodiment 63 
     The vial assembly of embodiment 62, wherein the vial assembly further comprises a ring that secures the stopper to the vial neck. 
     Embodiment 64 
     The vial assembly of any one of embodiments 48-62, further comprising a tamper-evident band. 
     Embodiment 65 
     The vial assembly of embodiment 63, wherein the end cap comprises a tamper-evident band that covers a portion of the annular lip, and the ring secures the temper-evident band and the stopper to the vial neck. 
     Embodiment 66 
     The vial assembly of any one of embodiments 48-65, wherein the bottom portion of the stopper comprises at least one truncated segment. 
     Embodiment 67 
     A method of filing a vial assembly comprising: 
     dispensing a liquid comprising the substance into a vial assembly comprising: 
     a vial having a vial body and a vial neck, the vial neck having a syringe interface; and 
     a vial cap having a central opening including a threaded segment that engages the syringe interface and a plug, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the vial cap; 
     wherein the liquid is dispensed through an open base of the vial body; and 
     sealing the base of the vial body after the liquid has been dispensed. 
     Embodiment 68 
     The method of embodiment 67, the vial cap further including a rim, the upper portion of the plug including a top portion defining a restraint coupled to a reduced diameter region defining an annulus, wherein the rim of the vial cap extends into the annulus to hold the plug in place. 
     Embodiment 69 
     The method of embodiment 68, wherein the plug further includes a central body with a diameter wider than the lower stopper portion. 
     Embodiment 70 
     The method of embodiment 68 or 69, further including the step of attaching the plug to the vial cap. 
     Embodiment 71 
     The method of embodiment 67, wherein the vial cap and the plug are coextruded. 
     Embodiment 72 
     The method of any one of embodiments 67-71, further including the step of attaching the vial cap to the vial neck. 
     Embodiment 73 
     The method of any one of embodiments 67-72, further including the step of lyophilizing the liquid prior to sealing the base of the vial body. 
     Embodiment 74 
     The method of any one of embodiments 67-73, further including the steps of: 
     detaching the vial cap from the vial neck, 
     attaching a syringe to the vial neck, and 
     drawing the liquid into the syringe. 
     Embodiment 75 
     The method of embodiment 67-74, further including the steps of: 
     detaching the vial cap from the vial neck, 
     attaching a syringe to the vial neck, 
     dispensing a second liquid into the vial after attaching the syringe to the vial neck, 
     drawing the liquid into the syringe. 
     Embodiment 76 
     The method of any one of embodiments 67-75, wherein the base of the vial body is sealed with a thermoformed plastic or foil. 
     Embodiment 77 
     The method of any one of embodiments 67-76, wherein the vial neck is tapered. 
     Embodiment 78 
     The method of any one of embodiments 67-77, wherein the syringe interface is a second threaded segment on an outer surface of the vial neck. 
     Embodiment 79 
     The method of any one of embodiments 67-77, wherein the syringe interface is a female luer. 
     Embodiment 80 
     A method of filling a vial assembly comprising: 
     dispensing a liquid into a vial comprising a vial body and a vial neck, the vial neck having a syringe interface; 
     attaching a first component of a vial cap to the vial neck, said first component having an internal threaded segment that engages the syringe interface and an outer surface comprising a plurality of longitudinally extending ribs separated by a plurality of longitudinally extending channels; and 
     sealing the vial by attaching a second component of the vial cap to the first component, said second component including a plurality of longitudinally extending prongs that engage with a surface in the channels on the outer surface of the first component, said second component further including a central opening formed by the plurality of longitudinally extending prongs, and a plug disposed in the central opening, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the second component. 
     Embodiment 81 
     The method of embodiment 80, wherein the second component further includes a rim, wherein the upper portion of the plug includes a top portion defining a restraint coupled to a reduced diameter region defining an annulus, and wherein the rim of the vial cap extends into the annulus to hold the plug in place. 
     Embodiment 82 
     The method of embodiment 81, wherein the plug further includes a central body with a diameter wider than the lower stopper portion. 
     Embodiment 83 
     The method of any one of embodiments 80-83, further including the step of attaching the plug to the second component of the vial cap. 
     Embodiment 84 
     The method of embodiment 80, wherein the second component and the plug are coextruded. 
     Embodiment 85 
     The method of any one of embodiments 80-84, wherein sealing the vial includes engaging an anchor on at least one of the prongs in the plurality of longitudinally disposed prongs with a counter-anchor disposed in a channel in the plurality of longitudinally disposed channels. 
     Embodiment 86 
     The method of any one of embodiments 80-85, wherein the first component of the vial cap is attached to the vial neck prior to dispensing the liquid into the vial. 
     Embodiment 87 
     The method of any one of embodiments 80-85, wherein the liquid is dispensed into the vial prior to attaching the first component of the vial cap to the vial neck. 
     Embodiment 88 
     The method of any one of embodiments 80-87, further including the steps of: 
     detaching the vial cap from the vial neck, 
     attaching a syringe to the vial neck, and 
     drawing the liquid into the syringe. 
     Embodiment 89 
     The method of any one of embodiments 80-87, further including the step of lyophilizing the liquid prior to sealing the vial. 
     Embodiment 90 
     The method of embodiment 89, further comprising partially engaging the second component with the first component without forming a seal prior to lyophilizing the liquid. 
     Embodiment 91 
     The method of any one of embodiments 80-87, 89 and 90, further including the steps of: 
     detaching the vial cap from the vial neck, 
     attaching a syringe to the vial neck, 
     dispensing a second liquid into the vial after attaching the syringe to the vial neck, and 
     drawing the liquid into the syringe. 
     Embodiment 92 
     The method of any one of embodiments 80-91, wherein the syringe interface is tapered. 
     Embodiment 93 
     The method of any one of embodiments 80-92, wherein the syringe interface is a second threaded segment on an outer surface of the vial neck. 
     Embodiment 94 
     The method of any one of embodiments 80-91, wherein the syringe interface is a female luer. 
     Embodiment 95 
     A method of filling a vial assembly comprising: 
     dispensing a liquid into a vial comprising a vial body and a vial neck; 
     attaching an adapter to the vial neck, said adapter comprising a top portion having a syringe interface, a bottom portion having a vial neck fitting, a gasket fitting within the vial neck fitting, and a longitudinally extending channel fluidly connecting the syringe interface to the vial neck; and 
     sealing the vial by attaching a vial cap to the adapter, said vial cap having a central opening including a threaded segment that engages the syringe interface and a plug, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the vial cap. 
     Embodiment 96 
     The method of embodiment 95, further comprising fitting the gasket along an inner edge of the vial neck fitting prior to attaching the adapter to the vial neck. 
     Embodiment 97 
     The method of embodiment 95 or 96, comprising attaching the vial cap to the adapter prior to attaching the adapter to the vial neck. 
     Embodiment 98 
     The method of any one of embodiments 95-97, the vial cap further including a rim, the upper portion of the plug including a top portion defining a restraint coupled to a reduced diameter region defining an annulus, wherein the rim of the vial cap extends into the annulus to hold the plug in place. 
     Embodiment 99 
     The method of embodiment 98, wherein the plug further includes a central body with a diameter wider than the lower stopper portion. 
     Embodiment 100 
     The method of embodiment 99, further including the step of attaching the plug to the vial cap. 
     Embodiment 101 
     The method of any one of embodiments 95-97, wherein the vial cap and the plug are coextruded. 
     Embodiment 102 
     The method of any one of embodiments 95-101, wherein the liquid is dispensed into the vial after attaching the adapter to the vial neck. 
     Embodiment 103 
     The method of any one of embodiments 95-102, further including the step of lyophilizing the liquid. 
     Embodiment 104 
     The method of embodiment 103, including the steps of: 
     placing the vial cap on the adapter in an unsealed configuration prior to lyophilizing the liquid; and 
     sealing the vial by tightening the vial cap after lyophilizing the liquid. 
     Embodiment 105 
     The method of any one of embodiments 95-102, further including the steps of: 
     detaching the vial cap from the vial neck, 
     attaching a syringe to the vial neck, and 
     drawing the liquid into the syringe. 
     Embodiment 106 
     The method of any one of embodiments 95-104, further including the steps of: 
     detaching the vial cap from the vial neck, 
     attaching a syringe to the vial neck, 
     dispensing a second liquid into the vial after attaching the syringe to the vial neck, and 
     drawing the liquid into the syringe. 
     Embodiment 107 
     The method of any one of embodiments 95-106, wherein the syringe interface is tapered. 
     Embodiment 108 
     The method of any one of embodiments 95-107, wherein the syringe interface is a second threaded segment on an outer surface of the vial neck. 
     Embodiment 109 
     The method of any one of embodiments 95-107, wherein the syringe interface is a female luer. 
     Embodiment 110 
     A method of filling a vial assembly comprising: 
     dispensing a liquid into a vial comprising a vial body and a vial neck the vial neck; and 
     sealing the vial by attaching a vial cap to the vial neck, the vial cap having:
         a stopper having a top portion and a bottom portion, the top portion comprising a longitudinal aperture, and the bottom portion that fits into the vial neck;   a conduit having a syringe interface at a first end and a barb at a second end, the second end fitting through the aperture in the stopper, and said barb engaging an underside of top portion of the stopper; and   an end cap having a central opening including a threaded segment that engages the syringe interface and a plug disposed in the central opening, said plug having a lower stopper portion that fits within the syringe interface of the conduit and an upper portion that attaches to an upper portion of the end cap.       

     Embodiment 111 
     The method of embodiment 110, wherein the end cap and the plug are coextruded. 
     Embodiment 112 
     The method of embodiment 110, wherein the end cap further includes a rim, wherein the upper portion of the plug includes a top portion defining a restraint coupled to a reduced diameter region defining an annulus, and wherein the rim of the end cap extends into the annulus to hold the plug in place. 
     Embodiment 113 
     The method of embodiment 112, wherein the plug further includes a central body with a diameter wider than the lower stopper portion. 
     Embodiment 114 
     The method of any one of embodiments 110-113, further including the step of attaching the conduit to the end cap. 
     Embodiment 115 
     The method of any one of embodiments 110-114, further including the step of attaching the conduit to the stopper. 
     Embodiment 116 
     The method of any one of embodiments 110-113, wherein the vial cap is pre-assembled. 
     Embodiment 117 
     The method of any one of embodiments 110-116, wherein the stopper includes an annular lip that sits on an annular lip disposed on an outer surface of the vial neck. 
     Embodiment 118 
     The method of embodiment 117, further including the step of securing the stopper to the vial neck by attaching a ring around the annular lip of the stopper and the annular lip of the vial neck. 
     Embodiment 119 
     The method of any one of embodiments 110-117, further including the step of lyophilizing the liquid prior to sealing the vial. 
     Embodiment 120 
     The method of embodiment 119, including the step of partially inserting the bottom portion of the stopper into the vial neck prior to lyophilizing the liquid. 
     Embodiment 121 
     The method of embodiment 119 or 120, including the step of fully inserting the bottom portion of the stopper into the vial neck after lyophilizing the liquid. 
     Embodiment 122 
     The method of any one of embodiments 110-119, further including the steps of: 
     detaching the vial cap from the vial neck, 
     attaching a syringe to the vial neck, and 
     drawing the liquid into the syringe. 
     Embodiment 123 
     The method of any one of embodiments 110-121, further including the steps of: 
     detaching the vial cap from the vial neck, 
     attaching a syringe to the vial neck, 
     dispensing a second liquid into the vial after attaching the syringe to the vial neck, and 
     drawing the liquid into the syringe. 
     Embodiment 124 
     The method of any one of embodiments 110-123, wherein the syringe interface is a second threaded segment on an outer surface of the vial neck. 
     Embodiment 125 
     The method of any one of embodiments 110-123, wherein the syringe interface is a female luer. 
     Embodiment 126 
     A method of filling a syringe, comprising: 
     detaching a vial cap from a vial, 
     the vial having a vial body and a vial neck, the vial neck having a syringe interface; and 
     the vial cap having a central opening including a threaded segment that engages the syringe interface and a plug, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the vial cap; 
     attaching a syringe to the vial neck; and 
     drawing a liquid contained within the vial into the syringe. 
     Embodiment 127 
     The method of embodiment 126, wherein the vial cap and the plug are coextruded. 
     Embodiment 128 
     The method of embodiment 126, wherein the vial cap further includes a rim, wherein the upper portion of the plug includes a top portion defining a restraint coupled to a reduced diameter region defining an annulus, and wherein the rim of the vial cap extends into the annulus to hold the plug in place. 
     Embodiment 129 
     The method of embodiment 128, wherein the plug further includes a central body with a diameter wider than the lower stopper portion. 
     Embodiment 130 
     A method of filling a syringe, comprising: 
     detaching a vial cap from a vial,
         the vial having a vial body and a vial neck, the vial neck having a syringe interface; and   the vial cap comprising a first component and a second component, said first component having an internal threaded segment that engages the syringe interface and an outer surface comprising a plurality of longitudinally extending ribs separated by a plurality of longitudinally extending channels, said second component including a plurality of longitudinally extending prongs that engage with a surface in the channels on the outer surface of the first component, said second component further including a central opening formed by the plurality of longitudinally extending prongs and a plug disposed in the central opening, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the second component;       

     attaching a syringe to the syringe interface of the vial neck; and 
     drawing a liquid contained within the vial into the syringe. 
     Embodiment 131 
     The method of embodiment 130, wherein the second component and the plug are coextruded. 
     Embodiment 132 
     The method of embodiment 130, wherein the second component further includes a rim, wherein the upper portion of the plug includes a top portion defining a restraint coupled to a reduced diameter region defining an annulus, and wherein the rim of the second component extends into the annulus to hold the plug in place. 
     Embodiment 133 
     The method of embodiment 132, wherein the plug further includes a central body with a diameter wider than the lower stopper portion. 
     Embodiment 134 
     The method of any one of embodiments 130-133, wherein at least one of the prongs in the plurality of longitudinally extending prongs comprises an anchor that engages a counter-anchor disposed in a channel in the plurality of longitudinally extending channels. 
     Embodiment 135 
     The method of any one of embodiments 126-134, wherein the vial neck is tapered. 
     Embodiment 136 
     The method of any one of embodiments 126-135, wherein the syringe interface is a second threaded segment on an outer surface of the vial neck. 
     Embodiment 137 
     The method of any one of embodiments 126-135, wherein the syringe interface is a female luer. 
     Embodiment 138 
     The method of any one of embodiments 126-137, wherein the step of detaching the vial cap includes unscrewing the vial cap. 
     Embodiment 139 
     The method of any one of embodiments 126-138, wherein the syringe comprises a male luer lock that interfaces with the syringe interface. 
     Embodiment 140 
     The method of any one of embodiments 126-139, further including the step of forming the liquid by adding a solution to the vial, and dissolving or suspending a lyophilized powder contained within the vial. 
     Embodiment 141 
     The method of any one of embodiments 126-140, wherein the step of detaching the vial cap includes severing a tamper-evident band from the vial cap. 
     Embodiment 142 
     A method of filling a syringe, comprising: 
     detaching a vial cap from a vial assembly comprising:
         a vial comprising a vial body and a vial neck;   an adapter comprising a top portion having a syringe interface, a bottom portion having a vial neck fitting attached to the vial neck, and a channel fluidly connecting the syringe interface to the vial neck;   a gasket disposed between the vial neck and the adapter; and   the vial cap; said vial cap having a central opening including a threaded segment that engages the syringe interface and a plug, said plug having a lower stopper portion that fits within the vial neck and an upper portion that attaches to an upper portion of the vial cap;       

     attaching a syringe to the syringe interface; and 
     drawing a liquid contained within the vial into the syringe. 
     Embodiment 143 
     The method of embodiment 142, wherein the end cap and the plug are coextruded. 
     Embodiment 144 
     The method of embodiment 142, the vial cap further including a rim, the upper portion of the plug including a top portion defining a restraint coupled to a reduced diameter region defining an annulus, wherein the rim of the vial cap extends into the annulus to hold the plug in place. 
     Embodiment 145 
     The method of embodiment 144, wherein the plug further includes a central body with a diameter wider than the lower stopper portion. 
     Embodiment 146 
     The method of any one of embodiments 142-145, wherein the syringe interface is tapered. 
     Embodiment 147 
     The method of any one of embodiments 142-146, wherein the syringe interface is a second threaded segment on an outer surface of a conduit. 
     Embodiment 148 
     The method of any one of embodiments 142-146, wherein the syringe interface is a female luer. 
     Embodiment 149 
     The method of any one of embodiments 142-148, wherein the syringe comprises a male luer lock that interfaces with the syringe interface. 
     Embodiment 150 
     The method of any one of embodiments 142-149, further including the step of forming the liquid by adding a solution to the vial, and dissolving or suspending a lyophilized powder contained within the vial. 
     Embodiment 151 
     The method of any one of embodiments 142-150, wherein the step of detaching the vial cap includes unscrewing the vial cap. 
     Embodiment 152 
     The method of any one of embodiments 142-151, wherein the step of detaching the vial cap includes severing a tamper-evident band from the vial cap. 
     Embodiment 153 
     A method of filling a syringe, comprising: 
     detaching an end cap from a vial assembly comprising:
         a vial having a vial body and a vial neck, the vial neck having an inner surface and an outer surface, the outer surface having an annular lip; and   a vial cap having:
           a stopper having a top portion and a bottom portion, the top portion comprising a longitudinal aperture, and the bottom portion that fits into the vial neck;   a conduit having a syringe interface at a first end and a barb at a second end, the second end fitting through the aperture in the stopper, and said barb engaging an underside of top portion of the stopper; and   
           the end cap; said end cap having a central opening including a threaded segment that engages the syringe interface and a plug disposed in the central opening, said plug having a lower stopper portion that fits within the syringe interface of the conduit and an upper portion that attaches to an upper portion of the end cap;       

     attaching a syringe to the syringe interface; and 
     drawing a liquid contained within the vial into the syringe. 
     Embodiment 154 
     The method of embodiment 153, wherein the end cap and the plug are coextruded. 
     Embodiment 155 
     The method of embodiment 153, wherein the end cap further includes a rim, wherein the upper portion of the plug includes a top portion defining a restraint coupled to a reduced diameter region defining an annulus, and wherein the rim of the end cap extends into the annulus to hold the plug in place. 
     Embodiment 156 
     The method of embodiment 155, wherein the plug further includes a central body with a diameter wider than the lower stopper portion. 
     Embodiment 157 
     The method of any one of embodiments 153-156, wherein the syringe interface is tapered. 
     Embodiment 158 
     The method of any one of embodiments 153-157, wherein the syringe interface is a second threaded segment on an outer surface of the conduit. 
     Embodiment 159 
     The method of any one of embodiments 153-157, wherein the syringe interface is a female luer. 
     Embodiment 160 
     The method of any one of embodiments 153-159, wherein the syringe comprises a male luer lock that interfaces with the syringe interface. 
     Embodiment 161 
     The method of any one of embodiments 153-160, further including the step of forming the liquid by adding a solution to the vial, and dissolving or suspending a lyophilized powder contained within the vial. 
     Embodiment 162 
     The method of any one of embodiments 153-161, wherein the step of detaching the vial cap includes unscrewing the end cap. 
     Embodiment 163 
     The method of any one of embodiments 153-162, wherein the step of detaching the vial cap includes severing a tamper-evident band from the vial cap.