Patent Publication Number: US-8540691-B2

Title: Drug solution transferring device

Description:
This nonprovisional application is based on Japanese Patent Application No. 2009-158910 filed on Jul. 3, 2009 with the Japan Patent Office, the entire contents of which are hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a drug solution transferring device, and particularly to a drug solution transferring device for transferring a toxic drug solution. 
     2. Description of the Background Art 
     In a medical institution such as a hospital, conventionally, a dry preparation such as a powdery drug or a freeze-dried drug, which is held in a drug container such as a vial, is dissolved in a solvent for use, and a resultant drug solution is used as an infusion for drip injection. Such a drug will lose its efficacy when it is kept in a state of a drug solution and, consequently, can not be stored in the state of the drug solution. An injection syringe filled with the solvent is connected to the drug container to inject the solvent into the drug container so that the dry preparation in the drug container is dissolved. 
     In process of dissolving and preparing a toxic drug such as anti-cancer drug, an injection syringe may be removed in such a state that a pressure is applied to a connection portion of the injection syringe or a hydraulic pressure in the infusion container is applied thereto. In this case, a splash or spill of the drug solution may occur at the connection portion even when the pressure is small. When the toxic drug splashes or spills, or when it dries thereafter, an aerosol generates and floats so that the toxic drug is exposed in an ambient environment for a long period of time, resulting in a problem that the toxic drug may exert an adverse influence on health of medical staffs and patients. 
     Accordingly, there has been proposed a drug solution preparing kit that does not cause the liquid leakage such as a splash and dispersion of an aerosol during preparation of a drug solution (e.g., International Publication No. WO2007/148708). 
     According to the drug solution preparing kit in International Publication No. WO2007/148708, when a drug that is already prepared is drawn into a barrel and then the barrel is separated from the transfusing tool, a sealing member provided at an end opening of the barrel closes to prevent leakage of the prepared drug. When the prepared drug solution is drawn into the barrel, the pressure in the system becomes lower than an ambient pressure. Therefore, even when a splash or aerosol spouts, the splash or the aerosol occurs inside the vial, and are prevented from external dispersing from the system. 
     According to the drug solution preparing kit in International Publication No. WO2007/148708, a vial is attached to a vial attaching unit of a transfusing tool, and a first needle covered with a covering member is stuck into an elastic film of the barrel to attach the barrel to the barrel attaching unit. In this state, the drug is dissolved and prepared in the vial, and subsequently a nominal volume of drug solution is drawn into the barrel. Then, the transfusing tool is removed from the barrel. 
     When the first needle is pulled out from the elastic film of the barrel, a residual toxic drug adhering to the first needle may adhere to a portion near a tip end of the covering member. The toxic drug adhering to the covering member may change into an aerosol. The aerosol thus generated floats, and is partially dried during floating to change into smaller particles of a high drug concentration. This results in a problem that the medical staffs and the patients are exposed to the toxic drug. 
     SUMMARY OF THE INVENTION 
     A primary object of the invention is to provide a drug solution transferring device that can suppress environmental dispersion of a toxic drug solution during transference of the drug solution. 
     A drug solution transferring device according to the invention includes a drug solution container provided with an opening; and a connection tool for connection to the drug solution container. The drug solution container includes an elastic member for closing the opening. The elastic member is formed of a plurality of membranes overlaid together. The membrane has a projection projecting into the drug solution container. The connection tool includes a needle having a sharp tip end. The needle has a liquid hole extending in an extending direction of the needle. When the needle penetrates through the projection of the membrane, an inside and an outside of the drug solution container are communicated with each other through the liquid hole to allow transference of the drug solution between the drug solution container and the connection tool. 
     Preferably, in the above drug solution transferring device, the projection has a hemispherical form. 
     Preferably, in the above drug solution transferring device, the connection tool includes a covering unit, a cylindrical portion and an elastic film. The covering unit covers the needle and is elastically deformable. The cylindrical portion has a hollow form, and accommodates the needle and the covering unit. The elastic film is arranged at an end portion of the cylindrical portion near the tip end of the needle, and covers the end portion. The elastic film has a slit opening. 
     Preferably, in the above drug solution transferring device, the drug solution container includes a pipe portion projecting toward an outside of the drug solution container. The elastic member is arranged to close a hollow in the pipe portion. The pipe portion has an outer diameter smaller than an inner diameter of the cylindrical portion for allowing insertion of the pipe portion through the slit opening into the cylindrical portion. The needle is stuck into the membrane by inserting the pipe portion into the cylindrical portion. 
     The drug solution transferring device according to the invention can suppress dispersion of a toxic drug solution to a surrounding environment during transference of the drug solution. 
     The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross section showing a structure of a drug solution transferring device according to a first embodiment of the invention. 
         FIG. 2  is a fragmentary cross section showing, on an enlarge scale, the drug solution transferring device shown in  FIG. 1 . 
         FIG. 3  is a schematic view of a second needle viewed in a direction of an arrow III in  FIG. 2 . 
         FIG. 4  is a plan of a connection tool viewed in a direction of an arrow IV in  FIG. 2 . 
         FIG. 5  is a cross section showing a state in which a pre-filled syringe is connected to a vial through the connection tool. 
         FIG. 6  is a cross section showing a state after a drug is prepared in the vial. 
         FIG. 7  is a cross section showing a state in which the prepared drug solution is re-drawn into the barrel. 
         FIG. 8  is a cross section showing a state in which the barrel filled with the prepared drug solution is separated from the connection tool. 
         FIG. 9  is a cross section showing a structure of a drug solution transferring device according to a second embodiment of the invention. 
         FIG. 10  is a fragmentary cross section showing, on an enlarge scale, the drug solution transferring device shown in  FIG. 9 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Embodiments of the invention will now be described with reference to the drawings. In the following description, the same or corresponding portions bear the same reference numbers, and description thereof is not repeated. 
     In the embodiments described below, each of components is not essential in the invention, unless otherwise specified. In the embodiments described below, numbers, amounts and the like are merely examples, unless otherwise specified, and the scope of the invention is not restricted to such numbers, amounts and the like. 
     First Embodiment 
     As shown in  FIG. 1 , a drug solution transferring device  100  according to a first embodiment includes a pre-filled syringe P filled with a solvent S and a connection tool  2  connected to pre-filled syringe P. Connection tool  2  is attached to pre-filled syringe P and a vial V containing the drug so that inner spaces thereof are communicated with each other. Owing to the communication between pre-filled syringe P and vial V through connection tool  2 , the drug contained in vial V is mixed and dissolved in a solvent S to prepare the drug solution. 
     Pre-filled syringe P has a cylindrical barrel  1  which is an example of a drug solution container and is open at its opposite ends. Barrel  1  has a nozzle  14  of a small diameter at its tip end. A sealing member  12  is attached to nozzle  14 . Sealing member  12  includes an elastic member  121  and a caulking member  122 . Elastic member  121  is liquid-tightly attached to nozzle  14  by caulking member  122 . Caulking member  122  is unremovable from nozzle  14 . As shown in  FIG. 2 , the caulking member  122  includes a step  1221  formed on an inner periphery of the caulking member, and the elastic member  121  is clamped between the step  1221  and the opening of the drug solution container to seal the opening of the drug solution container. 
     Nozzle  14  and caulking member  122  form a hollow pipe portion. Caulking member  122  is fixed to an outer periphery of nozzle  14  to form the pipe portion of an integrated structure together with nozzle  14 . Barrel  1  includes a pipe portion projecting outward from barrel  1 . The pipe portion is internally provided with a space  16 . An elastic member  121  is arranged to close space  16  in the pipe portion. The pipe portion is provided at its tip end portion (i.e., a tip end portion of caulking member  122 ) with an opening  10  forming an end opening of barrel  1 . Elastic member  121  closes opening  10 . 
     Elastic member  121  is formed of a plurality of membranes  121   a  and  121   b  overlaid together. A surface of membrane  121   a  near opening  10  and a surface of membrane  121   b  near the inside of barrel  1  are in intimate contact with each other. Elastic member  121  is formed of membranes  121   a  and  121   b  that are overlaid together to keep intimate contact without a space and thereby form an integrated elastic member. 
     Each of membranes  121   a  and  121   b  has a projection  123  projecting into barrel  1 . Projections  123  thus formed concave the surface of elastic member  121  opposed to opening  10 . The respective projections  123  formed at membranes  121   a  and  121   b  have the same form so that the surfaces of membranes  121   a  and  121   b  can be entirely in intimate contact. As shown in  FIG. 2 , projection  123  has a hemispherical form. 
     A gasket  11  is liquid-tightly and slidably fitted into barrel  1  through the rear end opening of barrel  1 . Gasket  11  is coupled to a plunger  13 . A space defined by barrel  1 , sealing member  12  and gasket  11  is filled with solvent S. 
     Connection tool  2  is used for establishing communicative connection between pre-filled syringe P and vial V, and includes a partition wall  25  as well as a barrel attaching unit  21  and a vial attaching unit  22  which are provided on opposite surfaces of partition wall  25 , respectively. Barrel attaching unit  21  has a hollow cylindrical form. Connection tool  2  includes barrel attaching unit  21  as an example of a cylindrical portion. 
     Barrel attaching unit  21  accommodates a first needle  231  that can penetrate through elastic member  121  of sealing member  12  of pre-filled syringe P when connection tool  2  is attached to pre-filled syringe P. First needle  231  is an example of a needle unit having a sharp tip end  231   a . First needle  231  has a liquid hole  234  extending in an extending direction (longitudinal direction in  FIG. 2 ) of first needle  231 . 
     As shown in  FIG. 2 , liquid hole  234  is open at tip end  231   a  of first needle  231 . First needle  231  is covered with a rubber cap  232  that is an example of a covering unit covering first needle  231 . Rubber cap  232  is elastically deformable. Barrel attaching unit  21  accommodates first needle  231  and rubber cap  232 . 
     Vial attaching unit  22  has a second needle  233  that can penetrate through a plug of vial V when vial V is attached to connection tool  2 . Second needle  233  is coaxial with first needle  231 . Second needle  233  has a liquid hole  237  extending in the extending direction of second needle  233 . Liquid holes  234  and  237  formed in first and second needles  231  and  233 , respectively, are communicated with each other via a communication space  235 . 
     As shown in  FIGS. 2 and 3 , the end of liquid hole  237  at the tip end of second needle  233  is open at the outer peripheral surface of second needle  233 . 
     Connection tool  2  further includes a port  24 . An aerosol filter  242  that can catch aerosol is arranged in port  24 . Second needle  233  is internally provided with a communication passage  236  independent of liquid hole  237 . Communication passage  236  allows second needle  233  and port  24  to be in communication with each other. 
     A cap  27  is attached to an end portion  26  of barrel attaching unit  21  near tip end  231   a  of first needle  231 . Cap  27  has an annular form, and is provided at its center with a circular through-hole extending through cap  27  in a thickness direction thereof. This through hole has a diameter slightly larger than an outer diameter of the pipe portion formed of nozzle  14  and caulking member  122 . Owing to the provision of the through hole, the pipe portion that is being inserted into barrel attaching unit  21  can be positioned to guide reliably first needle  231  and rubber cap  232  into the pipe portion, and cap  27  can hold barrel  1  when barrel  1  and connection tool  2  are connected together. 
     An elastic film  238  is held between end portion  26  and cap  27  fixed to end portion  26 . Elastic film  238  is arranged over end portion  26  of barrel attaching unit  21  to cover it. A plurality of projections are formed at each of the surface of end portion  26  opposed to elastic film  238  and the surface of cap  27  opposed to elastic film  238 . These projections fix and hold elastic film  238  between end portion  26  and cap  27 . Elastic film  238  has a circular exposed portion that is externally exposed through the circular through-hole formed in cap  27 . 
     As shown in  FIGS. 2 and 4 , elastic film  238  has a slit opening  239 , which has a straight from extending in a diametrical direction of the externally exposed circular portion of elastic film  238 . Slit opening  239  extends between one and the other ends of the externally exposed circular portion of elastic film  238 , and provides a boundary dividing the exposed portion into two semicircular portions. 
     Barrel  1  is a cylindrical member having a tip end, i.e., nozzle  14  and a base end, and are open at its opposite ends. Barrel  1  is normally made of glass or transparent plastic such as polypropylene, polyethylene, polymethylpentene or cyclic polyolefin. In barrel  1 , nozzle  14  is sealed with sealing member  12  and its inner cavity on the base end side is sealed with gasket  11  inserted from the open base end. The space in barrel  1 , which is defined by sealing member  12  and gasket  11 , is filled with solvent S in advance. When the space is filled with solvent S, gasket  11  is preferably located to left a space on the base end side such that a certain amount of gas exceeding a nominal volume can be drawn thereinto when the drug solution is prepared and re-drawn. Solvent S is normally and appropriately a physiological saline or a glucose solution. 
     Normally, gasket  11  is slidably inserted from the open base end side of cylindrical barrel  1 . Therefore, it takes a columnar form having a thickness that substantially prevents easy tilting of inserted gasket  11  as well as a size slightly smaller than a diameter of an inner peripheral wall of the barrel. Plunger  13  has a male screw at its tip end, and gasket  11  has a female screw at its inner cavity for receiving plunger  13 . Gasket  11  and plunger  13  may have structures other than above general and, for example, may have rotatable structures disclosed in Japanese Patent Laying-Open Nos. 2002-272843 and 2008-307237. 
     Gasket  11  has annular ribs which are formed at its tip and base end portions, and are slightly larger in diameter than the inner peripheral wall of the barrel. This structure keeps the liquid-tightness between the inner peripheral wall of barrel  1  and gasket  11  when plunger  13  moves. A material of gasket  11  largely depends on compatibility with a drug stored in barrel  1 , and is desirably natural rubber, butyl rubber, chlorinated butyl rubber, ethylene butadiene rubber, thermoplastic elastomer or the like. 
     Sealing member  12  is preferably formed of elastic member  121  and caulking member  122  as shown in  FIG. 2 . Membranes  121   a  and  121   b  forming elastic member  121  are thin membranes configured such that first needle  231  of connection tool  2  can readily penetrate through it and can be removed therefrom without loosing the liquid-tightness. Membrane  121   b  near opening  10 , i.e., on the tip end side of the pipe portion formed of nozzle  14  and caulking member  122  may be made of any material provided that membrane  121   b  has a large restoring force for canceling elastic deformation. For example, membrane  121   b  may be made of an elastic material such as a rubber material (e.g., isoprene rubber or silicone rubber). 
     Membrane  121   a  on the base end side of the pipe portion, i.e., on the inner side of barrel  1  may be made of the same material as membrane  121   b . However, when it is used in a storage container such as pre-filled syringe P, membrane  121   a  must be made of a material that does not dissolve in a drug solution. For example, membrane  121   a  may be made of a rubber material having a high chemical resistance such as butyl rubber. 
     Caulking member  122  must be made of a material having a relatively high modulus of elasticity so that it can be firmly and unremovably fitted or adhered into nozzle  14  at the tip end of barrel  1  and it can cooperate with elastic member  121  to keep the liquid-tightness. The material may be polypropylene, polycarbonate or aluminum. 
     First needle  231  is a syringe connection needle, and is covered with a rubber cap  232 . First needle  231  must be made of a material that allows easy penetration through elastic member  121  of sealing member  12  attached to nozzle  14  and allows easy resealing of rubber cap  232  when connection tool  2  is removed from barrel  1 . For example, first needle  231  is made of stainless steel, ABS (Acrylonitrile Butadiene Styrene) resin, SB (Styrene Butadiene) resin, polycarbonate or polystyrene. 
     Preferably, first needle  231  is worked and formed to locate tip end  231   a  on an axis or center of first needle  231  so that it can penetrate through a center of hemispherical projection  123 , i.e., a portion of projection  123  that protrudes into barrel  1  and is remotest from opening  10 . According to this structure, first needle  231  can preferably penetrate through membranes  121   a  and  121   b  with a circumferentially equal force so that a deformation of membranes  121   a  and  121   b  as well as leakage of the drug solution can be suppressed when first needle  213  penetrates therethrough. For example, first needle  231  is a bevel needle that is provided at tip end  231   a  with an obliquely cut opening that is cut obliquely to the extending direction of first needle  231 . In this case, a bending work can be effected on tip end  231   a  to locate tip end  231   a  on the axis of first needle  231 . 
     Preferably, rubber cap  232  has liquid-tightness so as to prevent leakage of the toxic drug when first needle  231  is stuck into or extracted from elastic member  121  of barrel  1 . This kind of rubber cap  232  is preferably made of an elastic material such as natural rubber or synthetic rubber that has certain flexibility, a high restoration property, liquid-tightness and a high resealing property. 
     It is preferable that second needle  233  can readily penetrate through a rubber plug in the inlet of vial V, and is made of a material such as ABS resin, SB resin, polycarbonate or polystyrene. Preferably, second needle  233  has no pinhole at its axial center in order to prevent generation of an aerosol, which will float for a long period of time, when solvent S is directly jetted to a dry drug or a liquid surface in vial V. Liquid hole  237  for introducing solvent S into vial V has an opening at the surface of second needle  233 , and this opening is preferably set in an appropriate position that can reduce a liquid remaining in vial V as far as possible when the prepared drug solution is re-drawn into barrel  1 . 
     Elastic film  238  arranged at end portion  26  of barrel attaching unit  21  can be made of any elastic material provided that it can be restored when a load is released from elastic film  238 . For example, elastic film  238  may be made of a rubber material such as isoprene rubber, butyl rubber or silicone rubber. Also, elastic film  238  can have any thickness provided that it is elastically restorable. 
     The form of slit opening  239  formed in elastic film  238  is not restricted to a form of a straight line, and it can have any form. For example, slit opening  239  may have a crosswise form. However, slit opening  239  of a straight-line form can be formed more easily than the others and thus is superior to the others. 
     Preferably, barrel attaching unit  21  is provided with a protruding piece or a lock mechanism for caulking barrel  1  slightly in order to prevent a disadvantage that a gap is formed at the peripheral edge of first needle  231  due to swaying during the operation and the toxic drug is dispersed therethrough. 
     Port  24  of connection tool  2  has an opening of communication passage  236  remote from second needle  233 . When barrel  1 , connection tool  2  and vial V are connected together with vial V located in the lower position, and plunger  13  is pushed to introduce solvent S in barrel  1  into vial V, the inner pressure applied to vial V discharges a gas from the system through communication passage  236 . Communication passage  236  operates as a gas discharge passage. Aerosol filter  242  is arranged inside port  24  so that the drug solution may not leak from the system through port  24 . 
     Aerosol filter  242  is made of water repellent resin such as polytetrafluoroethylene or ethylene-tetrafluoroethylene, or a hydrophobic material such as resin or fiber having a surface subjected to water repellent treatment. A pore diameter, a structure and a thickness of aerosol filter  242  are selected appropriately. However, an aerosol floating for a long period of time generally has a diameter in a range from about 10 nm to about 50 nm. In consideration of this as well as an electrostatic property and the like of the aerosol, a complex combination of a hydrophilic filter, a positively or negatively charged filter, an activated carbon and the like may be combined to form aerosol filter  242 . 
     A manner of using drug solution transferring device  100  having the above structure will be described below. As shown in  FIG. 5 , vial V is attached to vial attaching unit  22  of connection tool  2  with the inlet side thereof being directed upward. Then, vial V of which bottom is located in the lower position is stably placed on a desk or the like, and barrel  1  of which tip end is directed downward is attached to barrel attaching unit  21  of connection tool  2 . 
     Caulking member  122  attached to nozzle  14  at the end of barrel  1  has an outer diameter slightly smaller than an inner diameter of barrel attaching unit  21 . Thus, the outer diameter of the pipe portion formed of nozzle  14  and caulking member  122  is smaller than the inner diameter of barrel attaching unit  21 . Therefore, nozzle  14  and caulking member  122  can be inserted into barrel attaching unit  21  through slit opening  239  formed in elastic film  238 . 
     When the pipe portion formed of nozzle  14  and caulking member  122  is inserted into barrel attaching unit  21 , first needle  231  and rubber cap  232  accommodated in barrel attaching unit  21  enter space  16  in the pipe portion through opening  10 . Connection tool  2  is connected to barrel  1  with first needle  231  (i.e., a part of connection tool  2 ) inserted into opening  10  of barrel  1 . For example, the sizes of the pipe portion and barrel attaching unit  21  can be appropriately adjusted so that the inner peripheral surface of barrel attaching unit  21  is opposed to the outer peripheral surface of caulking member  122  with a minute space therebetween. By this adjustment, the pipe portion inserted into barrel attaching unit  21  can be positioned, and first needle  231  and rubber cap  232  can be reliably inserted into space  16  of the pipe portion. 
     When the pipe portion is further inserted into barrel attaching unit  21 , elastic member  121  arranged at the tip end of nozzle  14  comes into contact with rubber cap  232 . As the pipe portion moves relatively to barrel attaching unit  21 , rubber cap  232  pushed by elastic member  121  elastically deforms to come into contact with tip end  231   a  of first needle  231 . First needle  231  passes through rubber cap  232  and penetrates through membranes  121   a  and  121   b  forming elastic member  121 . 
     When the pipe portion is inserted into barrel attaching unit  21 , first needle  231  penetrates through projections  123  formed in membranes  121   a  and  121   b . For this penetration, elastic member  121  and first needle  231  are appropriately arranged. For example, first needle  231  is arranged on the axis of barrel attaching unit  21 , and projection  123  is arranged on the axis of the pipe portion. In this case, the pipe portion has the outer diameter slightly smaller than the inner diameter of barrel attaching unit  21 . This configuration can provide the structure in which first needle  231  can reliably penetrate through projection  123 . 
     When first needle  231  penetrates through membranes  121   a  and  121   b , the inside and outside of barrel  1  are communicated with each other through liquid hole  234  formed inside first needle  231 . Since first needle  231  penetrating through elastic member  121  protrudes into the inner space of barrel  1  that is liquid-tightly closed by barrel  1 , gasket  11  and sealing member  12 , solvent S filling barrel  1  can flow externally from barrel  1  through liquid hole  234  inside first needle  231 . Since liquid hole  234  of first needle  231  allows the inside and outside of barrel  1  to be in communication with each other, solvent S can be transferred from barrel  1  to connection tool  2 . 
     In the state where pre-filled syringe P and vial V are connected together through connection tool  2  as shown in  FIG. 5 , plunger  13  is slowly pushed downward with vial V located in the lower position. The movement of plunger  13  introduces solvent S from barrel  1  through liquid hole  234 , communication space  235  and liquid hole  237  into vial V, and sprays it onto the inner wall of vial V. Concurrently, the gas in vial V is discharged through communication passage  236  formed in second needle  233  and port  24  to the outside of the system. In this manner, solvent S in barrel  1  is transferred into vial V. When vial V is shaken after the transfer of solvent S, dry drug M (see  FIG. 5 ) in vial V is dissolved in solvent S to prepare the drug solution. 
     After preparing the drug solution by dissolving in vial V, drug solution transferring device  100  is turned upside down as shown in  FIG. 7  to locate vial V and pre-filled syringe P in the upper and lower sides, respectively. When plunger  13  is pulled downward in the above state, the drug solution is transferred from vial V into barrel  1  through liquid hole  234  in first needle  231 , and a nominal amount of the drug solution is pulled and collected into barrel  1 . The prepared drug solution is vial V is transferred into barrel  1 . The drug solution is transferred between barrel  1  and connection tool  2  through liquid hole  234 . 
     After the prepared drug solution is transferred from vial V to barrel  1  and barrel  1  is sealed, barrel  1  is removed from connection tool  2  as shown in  FIG. 8 . Then, a dedicated transfusion needle (not shown) is connected to the tip end of barrel  1  so that the drug solution in barrel  1  can be coinfused into a drip container as it is. 
     In the above state, it is preferable that gasket  11  is located rearward on the base end side of barrel  1  as compared with the position when barrel  1  is filled with solvent S. This configuration allows removal of pre-filled syringe P while keeping a reduced pressure in vial V. Therefore, even when the liquid leakage such as splash and the aerosol occur, these occur toward the inside of vial V so that dispersion of the drug solution to the surroundings can be avoided. 
     First needle  231  penetrating through elastic member  121  when barrel  1  was connected to connection tool  2  is pulled out from elastic member  121  when barrel  1  is separated from connection tool  2 . Since the drug solution flowed from vial V through liquid hole  234  in first needle  231  into barrel  1 , the drug solution has adhered onto tip end  231   a  of first needle  231 . When first needle  231  is pulled out from elastic member  121 , first needle  231  slides on elastic member  121  while keeping an intimate contact between its outer peripheral surface and elastic member  121 . First needle  231  moves relatively to elastic member  121  with a pressing force being applied to its periphery by elastic member  121 . The relative movement of first needle  231  causes an operation of squeezing or rubbing first needle  231  by elastic member  121 . 
     When first needle  231  is pulled out from elastic member  121 , elastic member  121  squeezing or rubbing first needle  231  removes the drug solution adhered onto the surface of first needle  231 . More specifically, membrane  121   b  near opening  10  rubs off the adhered drug solution from first needle  231 , and the drug solution thus removed is caught between membranes  121   a  and  121   b . Membrane  121   b  has projection  123  protruding into barrel  1 , and first needle  231  penetrates through projection  123  so that membrane  121   b  exhibits the squeezing or rubbing function. Since the plurality of membranes  121   a  and  121   b  are overlaid together to form elastic member  121 , the drug solution can be caught between the plurality of membranes  121   a  and  121   b.    
     In drug solution transferring device  100  according to the first embodiment, as described above, elastic member  121  can remove the drug solution adhered onto first needle  231  so that drug solution transferring device  100  can suppress remaining of the drug solution on the surface of first needle  231 . The drug solution rubbed off by elastic member  121  from first needle  231  is caught between the plurality of membranes  121   a  and  121   b  so that drug solution transferring device  100  can suppress the dispersion of the drug solution removed from first needle  231  to the outside of the system from elastic member  121 . Therefore, when the toxic drug solution is to be transferred, such a state can be suppressed that the drug solution changes into an aerosol to splash and spread to a surrounding environment. Consequently, such a situation can be suppressed that workers such as medical staffs and patients using the drug solution are exposed to the aerosol of a high drug concentration and their health is impaired. Therefore, the embodiment can provide the easy-to-handle and safe drug solution transferring device  100 . 
     When membranes  121   a  and  121   b  are made of a rubber material having a large restoring force, these exhibit the rubbing function described above so that the drug solution can be rubbed and removed from first needle  231 . However, if membrane  121   b  had an extremely small thickness, the rubbing function of membrane  121   b  would probably be low. Therefore, it is desired to employ membrane  121   b  having a sufficient thickness for removing the drug solution from first needle  231 . 
     Projections  123  formed in membranes  121   a  and  121   b  have the hemispherical form. Projection  123  can have an arbitrary form provided that it protrudes toward the inside of barrel  1 , and may have a conical or pyramidal form. However, projection  123  of the first embodiment, i.e., dome-shaped projection  123  is more preferable because it can stably exhibit the function of rubbing off the drug solution from the surface of first needle  231  by membrane  121   b  even when first needle  231  penetrates through a position deviated from the center of projection  123 . 
     Further, drug solution transferring device  100  of the first embodiment is provided with elastic film  238  covering end portion  26  of barrel attaching unit  21 . Nozzle  14  and caulking member  122  on the end of barrel  1  extends into barrel attaching unit  21  through slit opening  239  formed in elastic film  238 . Even if the toxic drug solution remaining on the outer surface of first needle  231  adheres to rubber cap  232  when barrel  1  is being removed from connection tool  2 , the above structure can suppress the dispersion of the drug solution adhered onto rubber cap  232  to the outside of the system because elastic film  238  covers the inner space of barrel attaching unit  21 . 
     Therefore, the first embodiment can further suppress the external dispersion of the aerosol of drug solution. 
     Second Embodiment 
     As shown in  FIG. 9 , a drug solution transferring device according to a second embodiment includes a drug solution-filled syringe P filled with a toxic drug solution T and a connection tool  3  connected to drug solution-filled syringe P. Connection tool  3  is attached to an infusion container C filled with a drug solution L and drug solution-filled syringe P for connecting them together. Since drug solution-filled syringe P and infusion container C are in communication with each other through connection tool  3 , drug solution L in infusion container C and toxic drug solution T are mixed and dissolved together. 
     Drug solution-filled syringe P has the same structure as the pre-filled syringe in the first embodiment, and therefore description thereof is not repeated. Drug solution-filled syringe P filled with toxic drug solution T may be a pre-filled syringe that is filled in advance with toxic drug solution T or a syringe filled with a drug solution prepared by drug solution transferring device  100  of the first embodiment. 
     As shown in  FIG. 10 , connection tool  3  has a central axis extending in the direction of penetration through a plug of infusion container C, is provided at the upper and lower ends with a second needle  33  and an output port  35 , respectively, and has a cylindrical barrel attaching unit  31  protruding obliquely downward. Barrel attaching unit  31  has a first needle  331  that is located in the coaxial position for penetrating through elastic member  121  of sealing member  12  at the end of barrel  1  when drug solution-filled syringe P is attached to barrel attaching unit  31 . First needle  331  is covered with a covering unit, i.e., a rubber cap  332 . First needle  331  has a liquid hole  334 , which opens at a tip end  331   a  of first needle  331 . 
     A cap  37  is attached to an end portion  36  of barrel attaching unit  31  near tip end  331   a  of first needle  331 . An elastic film  338  is held between end portion  36  and a cap unit  37  fixed to end portion  36 . Elastic film  338  is arranged on end portion  36  of barrel attaching unit  31 , and covers end portion  36 . Elastic film  338  is provided with a slit opening  339 . Slit opening  339  has a form of straight line extending in a diametrical direction of an externally exposed circular portion of elastic film  338 . 
     Second needle  33  is provided with a liquid hole  333  and a communication passage  336  independent of each other. Liquid hole  333  is in communication with liquid hole  334  of first needle  331 . Communication passage  336  is in communication with output port  35 . A closing member  351  through which a bottle needle of an infusion line will penetrate is arranged at the end of output port  35 . 
     A liquid valve  322  that can bidirectionally open in response to a predetermined pressure or more is arranged on the base end side of barrel attaching unit  31 . When liquid holes  334  and  333  of first and second needles  331  and  33  are communicated with each other to transfer toxic drug solution T from barrel  1  to infusion container C by a pressure, and this pressure opens liquid valve  322 . Liquid valve  322  opens only when the liquid pressure is equal to or higher than a predetermined pressure. Therefore, when the infusion line is connected to output port  35  of connection tool  3  to transfer the drug solution from infusion container C to the infusion line, liquid valve  322  prevents returning of the drug solution into barrel  1 . Liquid valve  322  described above may be replaced with a one-way valve that allows a flow of liquid from liquid hole  334  to liquid hole  333  and prohibits a flow in the reverse direction so that toxic drug solution T can be irreversibly transferred from barrel  1  to infusion container C. 
     First needle  331  is covered with rubber cap  332  to ensure the liquid tightness for preventing leakage of the toxic drug when the needle is stuck into or extracted from elastic member  121  of barrel  1 . The material of first needle  331  is required to allow easy penetration through elastic member  121  of sealing member  12  attached to nozzle  14  and to allow easy resealing by rubber cap  332  when barrel  1  is removed. For example, first needle  331  may be made of stainless steel, ABS resin, SB resin, polycarbonate or polystyrene. 
     Rubber cap  332  is preferably made of an elastic material such as natural rubber or synthetic rubber that has certain flexibility and a high restoring property as well as high liquid-tightness and a high sealing property. 
     Preferably, second needle  33  is configured to allow easy sticking through the plug of infusion container C, and is made of ABS resin, SB resin, polycarbonate or polystyrene. Preferably, the openings of liquid hole  333  and communication passage  336  formed on the surface of second needle  33  are appropriately spaced from each other for promoting dilution of toxic drug solution T in infusion container C. For example, it is preferable that the needle hole is not formed on the central axis of second needle  33 . 
     Preferably, barrel attaching unit  31  is provided with a protruding piece or a lock mechanism for slightly caulking barrel  1  after attaching barrel  1  so as to prevent such a situation that a space is formed around first needle  331  due to sway during the operation and thereby the toxic drug disperses therethrough. Elastic film  338  arranged at end portion  36  of barrel attaching unit  31  is made of an elastic material, which is not restricted provided that it can restore when a load is released from elastic film  338 . For example, elastic film  338  may be made of a rubber material such as isoprene rubber, butyl rubber or silicone rubber. 
     Output port  35  of connection tool  3  is in communication with communication passage  336  formed in second needle  33 , and is closed by a closing member  351  such that output port  35  can open to the infusion line connected thereto. Closing member  351  is normally a thin film having elasticity so that it allows sticking of the bottle needle of the infusion line, does not allow easy disengagement of the bottle needle in the sticking position and does not impair the liquid-tightness. A material of closing member  351  satisfying the above performance is determined in view of compatibility with a drug solution in contact with it, and is appropriately selected from among natural rubber, butyl rubber, chlorinated butyl rubber, styrene butadiene rubber, thermoplastic elastomer and the like. The opening of output port  35  preferably has a cylindrical form having an inner diameter slightly smaller than the diameter of the bottle needle for assisting holding of the bottle needle of the infusion line. 
     Similarly to drug solution transferring device  100  of the first embodiment, the drug solution transferring device having the above structures can remove the drug solution adhered to first needle  331  by elastic member  121 , and therefore can suppress remaining of the drug solution on the surface of first needle  331 . The drug solution rubbed off from first needle  331  by elastic member  121  is caught between the plurality of membranes  121   a  and  121   b  so that such a situation can be suppressed that the drug solution removed from first needle  331  disperses through elastic member  121  to the outside of the system. Therefore, it is possible to suppress such a situation that the toxic drug solution takes an aerosol form and disperses to the surrounding environment during transference of the drug solution. 
     Further, end portion  36  of barrel attaching unit  31  is covered with elastic film  338 . Nozzle  14  and caulking member  122  at the tip end of barrel  1  are inserted into barrel attaching unit  21  through slit opening  339  formed in elastic film  338 . According to this configuration, elastic film  338  covers the inner space of barrel attaching unit  31 . Therefore, even in the case where the toxic drug solution remaining on the outer surface of first needle  331  adheres to rubber cap  332  when barrel  1  is removed from connection tool  2 , it is possible to suppress dispersion of the drug solution adhering to rubber cap  332  to the outside of the system because elastic film  338  covers the inner space of barrel attaching unit  31 . This can further suppress the external dispersion of the aerosol of the drug solution. 
     The first and second embodiments have been described in connection with the examples in which elastic member  121  of barrel  1  includes two membranes  121   a  and  121   b . This structure is not restrictive. It is merely required that elastic member  121  includes two or more membranes overlaid together, because it is employed for rubbing off the drug solution adhering to the first needle by the membrane near opening  10  of barrel  1 , catching the rubbed-off drug solution between the plurality of membranes and thereby suppressing the dispersion of the drug solution. As the number of membranes increases, elastic member  121  can remove the drug solution from the first needle more effectively. However, as the number of membranes increases, the difficulty in sticking the first needle through elastic member  121  increases. Therefore, it is desirable to set appropriately the number of the membranes in view of the drug solution removing performance of elastic member  121  and the degree of easiness with which the first needle can be stuck through elastic member  121 . 
     Connection tool  2  of the first embodiment connects pre-filled syringe P to vial V, and connection tool  3  of the second embodiment connects drug solution-filled syringe P to infusion line (not shown). However, the drug solution transferring device according to the invention is not restricted to the above example. The drug solution transferring device according to the invention can be used for transferring any liquid of which external leakage is to be suppressed. 
     For example, in addition to dangerous drug such as anti-cancer drug, the drug solution transferring device of the invention can be used for transferring a liquid containing pathogenic bacteria, bacteria to be prevented from having resistance, or the like. Specifically, the drug solution transferring device according to the invention can be appropriately used, e.g., for transferring a drug solution from a pre-filled syringe to a drug bag, for transferring an infusion from an infusion line to an empty syringe for sampling, for transferring a liquid specimen containing pathogenic bacteria from a specimen collecting tool to an inspection kit. Also, the drug solution transferring device according to the invention can be used for transferring a dangerous solvent such as trichloroethylene or a solution containing an endocrine-disrupting substance. 
     Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the scope of the present invention being interpreted by the terms of the appended claims.