Abstract:
An improved vial for supplying fluids, such as volatile and toxic fluids, without risking contamination or escape of the fluid before use comprises a sealed glass body containing the fluid. One end of the vial has a weakened area therein of a predetermined thickness which is sufficiently thin that the weakened area can be pierced by a needle without damaging the needle. The vial is be placed in a standard autosampler jar so that the weakened area is adjacent the elastomeric closure. Samples are drawn by plunging a needle through an exposed portion of the closure and into the jar. When the needle is inserted into the jar, it also pierces the weakened area of the vial providing safe access to the fluid contained therein.

Description:
FIELD OF THE INVENTION 
     This invention is directed to a glass vial for storing a fluid and which can be pierced with a needle to permit subsequent removal of the fluid. 
     BACKGROUND OF THE INVENTION 
     It is common in many industries, such as laboratory, medical, and photographic, to use volatile and toxic fluids. Often, these fluids are supplied in containers which store a measured quantity of the substance, such as a single unit or dose. A typical container used for these purposes is a glass autosampler jar  10 , such as illustrated in FIG.  1 . The jar  10  includes a body  12  for containing the fluid and a cap  14 . The jar is sealed using an elastomeric closure, such as a rubber septum  18  placed between the cap  14  and the jar&#39;s mouth. To permit safe removal of the contained fluid, the cap  14  has an opening  16  in it which exposes the underlying rubber septum  18 . The fluid is extracted from the jar by piercing the septum  18  with a hollow needle and drawing the fluid through the needle. Extraction can be performed manually, such as when the jar contains a unit dose of medicine to be injected into a patient by a doctor, or automatically, as when the jars are processed by automated machinery. 
     Although an elastomeric closure is generally required to provide a secure seal, elastomeric closures are not suitable for use with many types of compounds. In some cases, the fluid compound in the jar can leach through the closure and escape, posing a health risk to the handler. In other instances, the stored compound can cause breakdown in the closure material which can result in escape of the fluid or contamination of the fluid sample itself from chemicals escaping the closure. See, e.g., J. Milano and L. Bailey, “ Evaluation of Current Compendial Physiochemical Test Procedures for Pharmaceutical Elastomeric Closures and Development of an Improved HPLC Procedure ,” PDA Journal of Pharmaceutical Science &amp; Technology, Vol. 53, No. 4, p. 202-210 (July 1999). 
     One solution to this problem is to limit the amount of time the fluid is stored within the needle-piercable jar  10  by filling the jar shortly before it is to be used. 
     To this end, many volatile and toxic fluids are provided in sealed glass vials  20 , such as illustrated in FIG.  2 . The vial is filled with the desired fluid  22  and the vial is sealed by melting the glass at the open top. To open the vial  20 , the neck  24  is scored using a diamond scribe or other tool to create a weakened area and the top  26  of the vial  20  is snapped off. The fluid is then extracted from the vial  20  and added to the autosampler jar  10 , e.g., by pouring the fluid in or transporting it via a syringe or pipette. 
     Various techniques have been developed to safely remove the top of a sealed vial  20  and then transport the fluids from the vial into the jar  10 . However, because in all cases the vial  20  is opened before its contents are placed in the jar  10 , the risk of contamination or escape of the fluid is always present. Accordingly, there is a need to provide a method for supplying volatile and toxic fluids in a manner which permits them to be placed in a jar  10  sealed with an elastomeric closure without risking contamination or escape of the fluid or breakdown of the closure. 
     SUMMARY OF THE INVENTION 
     An improved vial for supplying fluids, such as volatile and toxic fluids, without risking contamination or escape of the fluid is disclosed. The vial comprises a glass body having a sealed first end and an open second end. The first end has a weakened area therein of a predetermined thickness which is sufficiently thin that the weakened area can be pierced by a needle without damaging the needle. The vial is filled with the desired fluid and then the second end is sealed, e.g., by melting the glass at the second end using a micro-flame. 
     In use, the vial is placed within a standard autosampler jar such that the weakened first end is adjacent to the elastomeric closure through which samples are to be drawn. An elastic spacer can be placed on the second end of the vial to protect it within the jar and to press the weakened end of the vial upwards against the closure. Samples are drawn in the conventional manner by plunging a needle through an exposed portion of the closure and into the jar. When the needle is inserted into the jar, it also pierces the weakened area of the vial providing safe access to the fluid contained therein. 
     Advantageously, the fluid contained in the vial remains sealed until the moment when the sample is drawn. This greatly minimizes the likelihood of the sample being contaminated or operators coming into contact with the fluid. In addition, because the closure is not exposed to the fluid until the sample is actually drawn, the fluid (within the sealed vial) can be stored inside the vial for extended periods of time without concern as to whether the fluid will interact detrimentally with the closure. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing and other features of the present invention will be more readily apparent from the following detailed description and drawings of illustrative embodiments of the invention in which: 
     FIG. 1 is an illustration of a conventional autosampler jar; 
     FIG. 2 is an illustration of a conventional sealed glass vial for storing a fluid; 
     FIGS. 3 a  and  3   b  are side views of an unfilled injectable vial; 
     FIG. 4 is a side view of a filled injectable vial; 
     FIG. 5 is a side view if the vial of FIG. 4 fitted with an elastic spacer; 
     FIG. 6 is a side view of an autosampler jar containing the vial of FIG. 5; and 
     FIG. 7 is a side view of an alternative embodiment for an injectable vial. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIGS. 3 a  is a side view of an unfilled injectable vial  30  according to the invention. The vial  30  has a body  32 , such as an elongated cylindrical body, which has a first end  34  which is sealed and second end  36  which is open. The vial  30  is preferably made of glass. However, other glass-like or even non-glass substances known to those of skill in the art could be used instead. The specific material used should be able to securely contain and not react with the fluids of interest. The vial  30  can be formed in various configurations and dimensions. FIG. 3 b  shows specific dimensions for a particularly preferred embodiment of the vial  30 . 
     As shown in FIG. 4, once the vial  30  is filled with the desired fluid  22 , the open second end  36  is sealed. The preferred method of sealing the vial  30  is by melting the vial material in the region of the second so that it flows together to form an end-wall  44 . If a sufficiently small and hot flame is used, the open end can be sealed without substantial heating of the contained fluid. To aid in the sealing process, a ridge or bubble of material  38  can be formed in the region near the open end  36 . Various techniques for sealing glass vials are well known to those of skill in the art. 
     According to one aspect of the invention, the first end  34  has a weakened area  40  formed therein, at least a portion of which has a predetermined thickness. The predetermined thickness is selected to be sufficiently thin to permit the weakened area to be piercable by a standard needle without the needle being substantially deformed. As will be discussed more fully below, this weakened area provides access to a fluid contained within vial  30 . In a preferred embodiment, the weakened area is an inward facing dimple or indentation as shown. This feature can be formed in whole or part by drilling-out a part of the first end or by stretching the wall inwards while that portion of the vial is molten, e.g., during a molding process. Other suitable fabrication techniques will also be known to those of skill in the art. 
     The specific predetermined thickness depends upon the sale of the vial  30 , the material it is formed from, and the type of needle which the vial  30  is designed to be pierced with. The material should be thick enough to prevent unwanted breakage but not so thick that the weakened area is unnecessarily hard to puncture with a needle. Some flexing and bending of the needle when piercing the weakened area  40  of the vial  3  is expected and normal. This minor deformation can result from slight misalignments of the needle from the piercing axis. However, the weakened area should be piercable without having to apply a pressure which would substantially deform the needle to the point of causing damage, such as a permanent bend or buckling of the needle wall. 
     Turning to FIGS. 5 and 6, once the vial  30  is filled and sealed, it can be distributed for subsequent use. In one implementation, the vial  30  is sized to be placed within a conventional autosampler jar  12 . The vial is positioned so that the first end  34  is up. When the jar is closed, the weakened area  40  is adjacent the elastomeric closure  18  and generally aligned with the portion  16  of the jar lid  14  which is designed to be pierced by the needle. As will be appreciated, when a needle is inserted into the vial, the needle will subsequently pierce the weakened area  40  of the vial and thereby gain access to the fluid contained therein. Advantageously, the weakened area is centered within a generally conical or bowl shaped area as shown so that a needle hitting the first end of the vial is guided towards a central weakest area. 
     Preferably, an elastic spacer  46  is positioned on the second end of the vial  30 . The spacer  46  protects the second end of the vial  30  from damage. It also can provide an elastic force which pushes the vial  30  upwards into the cap to keep the first end of the vial in contact with the elastomeric closure. The spacer  46  can be added by the user as needed or distributed already attached to the sealed vial. 
     In one embodiment, the vial  30  is formed from a soft glass which is relatively easy to melt and is designed to be pierced with standard stainless steel needles suitable for conventional chemical analysis or medical usage. Needles of this type generally have diameters in the range of about 0.03 inches to about 0.08 inches (e.g., from about 22 gauge to 33 gauge). For these needles, it has been found that for a vial sized generally as shown in FIG. 3 b  and formed of a conventional glass, a weakened area having a thickness ranging from between about 0.003 inches to 0.013 inches provides an acceptable balance between structural integrity and piercability. Most preferably, the thickness range is between 0.003 and 0.005 inches. 
     Based upon experimental results, a glass vial having a weakened area with a thickness nominally within the broader range has a breakage pressure ranging between about 1860 psi to 10,225 psi with the mean pressure equal to about 4800 psi. Because the tip of even a large needle covers a very small area, even very high relative pressures can be easily applied. For example, using a needle with a tip diameter of about 0.01 inches, this range of pressures can be generated using a force of only between about 8 ounces and 44 ounces. As will be appreciated, the particular optimal predetermined thickness range depends on the hardness and breaking characteristics of the vial material as well as the type of needle which is expected to be used. Thus, while the specific ranges discussed above are suitable for the preferred implementation, other ranges may be more appropriate for different configurations. 
     Turning to FIG. 7, there is shown an alternative embodiment of a vial  50 . The vial  50  is formed with a sealed end  52  and an open end  58 . After the vial  50  is filled with fluid  60 , the vial is sealed using an inert  54 , such as a glass insert, which is placed within the open end of the vial and secured in place by, e.g., melting the glass around the rim, using adhesive, or even a friction fit. The weakened area can be formed as discussed above. Alternatively, the weakened area can be formed by forming one or more notches  56  in the insert either before or after the vial is sealed. Other variations are also possible. For example, the vial of FIG. 3 a  could be formed with a flattened first end  34  and the weakened area formed by scoring or notching the end in a manner similar to the weakened insert. 
     Another design aspect to consider is the size of any pieces of the vial  30  which may fall into the fluid when the weakened area  40  is pierced by a needle. Based on experimental testing of vials designed according to the specific most preferred parameters discussed above, the size of glass particles which fall into the contained fluid is distributed from between about 2 microns to 20 microns with a mean particle size of about 5 microns. Thus, the weakened area remains substantially intact during the piercing and removing operation. In general, the particles have no effect on the sample because differences in density between the glass particles and the fluid result in rapid settling of the particles to the bottom of the vial. Although there is a slight possibility of the particles being aspirated into the needle, such particles can easily be removed through the use of a conventional sub-micron syringe filter. 
     To further reduce the likelihood of particles entering the liquid, a film, such as a polymer film of suitable low molecular weight like polyolefin polymer (e.g., polyethylene), can be applied over the weakened part of the vial. The film (not shown) can be applied to the vial using various techniques known to those of skill in the art, including vapor deposition or application of a suitable liquid polymer solution. When the vial is subsequently pierced by a needle, the film will adhere to the fragmented particles and prevent them from falling into the enclosed liquid. 
     While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.