Abstract:
Syringe systems for mixing and delivery of particles into the body are disclosed. In some embodiments, a mixing and delivery medical syringe system can include a barrel including first and second detachable sections, and first and second compartments communicable through a conduit.

Description:
TECHNICAL FIELD 
     This invention relates to mixing and delivery of therapeutic compositions. 
     BACKGROUND 
     Therapeutic vascular occlusions (embolizations) are induced by the introduction of various substances (embolic material, such as embolic particles) into a patient&#39;s circulatory system for the purpose of occluding vessels, either to arrest or to prevent hemorrhaging or to defunctionalize a structure or an organ. Typically, the components of an embolic composition-embolic particles in hydrating material (such as saline) and contrast agent (used for tracking the path of the embolic particles inside the body) are stored separately and mixed together at the time of injection into the body by the physician. 
     SUMMARY 
     In one aspect the invention features a mixing and delivery medical syringe system. The medical syringe system includes a barrel including first and second detachable sections, and first and second compartments communicable through a conduit. 
     In another aspect the invention feature a mixing and delivery medical syringe system. The medical syringe system includes a barrel having first and second compartments arranged in parallel along the barrel, the compartments communicable through a pressure-activated conduit. 
     In another aspect, the invention features a kit for medicant mixing and delivery, including a syringe system, which includes a barrel assembled from multiple sections, including a first section having a first chamber, and a second section having a second chamber. The syringe system includes a conduit between the first and second chambers through which flow can be controlled. The kit further includes a first container containing a first composition, and a second container containing a second composition. 
     In another aspect, the invention features a method for delivering injectable polymer particles by providing a syringe. The syringe includes a first compartment and a second compartment. A first component including injectable particles is loaded into at least one compartment, and the syringe is actuated to deliver the particles. 
     Embodiments can include one or more of the following. The conduit can include a pressure-activated separator. The separator can include a failure membrane. The failure membrane can include a weakened region. The weakened region preferentially effects rupture about a central region of the membrane. The weakened region preferentially affects rupture such that an attachment portion is not ruptured. The pressure-activated conduit can include a valve. 
     The first and the second compartments can be arranged serially along the syringe barrel. The barrel can include a vent valve. The barrel can include a fluid outlet and the outlet can include a valve. The first section can include the first chamber and the second section can include the second chamber. The conduit can be in one of the first or second sections. 
     The first composition can include injectable polymer particles. The particles can be embolic particles. The second composition can be a contrast agent. Alternatively, the second composition can include an anticancer agent. 
     The syringe can include a conduit between the compartments. A first component including injectable particles is loaded into at least one compartment and a second component is loaded into the second compartment. The first component and the second component are mixed in the syringe by flowing at least one of the components through the conduit. The second component can include a contrast agent. The second component can include a drug. 
     The method can include loading a second composition in the second compartment. The second composition can include polymer particles. The first component and second component can be delivered sequentially. 
     The first component and the second component can include polymer particles of different sizes or alternatively, of different shapes. The first component can include particles that are substantially spherical. 
     Embodiments may include one or more advantages. For example, pre-mixing the components may be undesirable because the shelf life of the mixed composition may be reduced for e.g., due to chemical interactions between a contrast agent and embolic particles. 
     The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages of the invention will be apparent from the description and drawings, and from the claims. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG. 1A  is a cross-sectional schematic of a syringe apparatus for mixing and delivery of a composition into the body. 
         FIG. 1B  is an enlarged cross-sectional view showing a failure membrane of the syringe of  FIG. 1A . 
         FIG. 1C  is a top view of the failure membrane of the syringe of  FIG. 1A . 
         FIG. 1D  illustrates mixing of the components using the syringe of  FIG. 1A . 
         FIG. 1E  illustrates delivery of a mixture through a catheter using the syringe of  FIG. 1A . 
         FIG. 2  is a schematic of a kit for mixing and delivery of a composition. 
         FIG. 3A  is a cross-sectional schematic of a syringe apparatus for mixing and delivery of a composition into the body. 
         FIG. 3B  is a top view of a failure membrane of the syringe of  FIG. 3A . 
         FIGS. 3C and 3D  illustrate mixing of the components of a composition using the syringe system of  FIG. 3A . 
         FIG. 3E  illustrates delivery of a mixture through a catheter using the syringe of  FIG. 3A . 
         FIG. 4A  is a cross-sectional schematic of a syringe apparatus for mixing and delivery of a composition into the body. 
         FIG. 4B  illustrates mixing of the components of a composition using the syringe of  FIG. 4A   
         FIG. 4C  illustrates delivery of a composition through a catheter using the syringe of  FIG. 4A . 
         FIG. 4D  is a top view of a plunger lock of the syringe of  FIG. 4A . 
         FIG. 5A  is a cross-sectional schematic of a syringe apparatus for mixing and delivery of particles of different sizes. 
         FIG. 5B  is a cross-sectional schematic of a syringe apparatus for mixing and delivery of particles of different shapes. 
     
    
    
     Like reference symbols in the various drawings indicate like elements. 
     DETAILED DESCRIPTION 
     Referring to  FIG. 1A , a syringe apparatus  1  includes a body with an upper compartment  2 , a lower compartment  3 , a plunger  4  with a plunger base  11 , a membrane  5 , and a connector  9 , which could be a luer connector, fitted with a stopcock  10 . The lower compartment  3  contains a contrast agent  6  and the upper compartment  2  contains a combination of particles such as embolic particles  7  and a hydrating fluid such as saline  8 . The upper compartment  2  and lower compartment  3  are fitted together at junction  19 . The membrane  5  can be made of a polymer material or of cellulose based materials, such as cellulose acetate, that provides a liquid-tight seal between the upper and lower compartments so that the contrast agent may be isolated from interaction with the embolic material and saline mixture until the time of injection into the body. 
     Referring to  FIGS. 1B and 1C , expanded views of the membrane  5  are illustrated. The membrane  5  has a failure region  13  and a hinge region  14 . In one embodiment, the failure and hinge regions can be regions of reduced thickness. The thickness of the failure region  13  is less than the thickness of the hinge region  14  such that the membrane will fail preferentially at the failure region  13  and bend preferentially at the hinge region  14 , in response to pressure increase in the upper compartment  2 . Referring to  FIG. 1C , a top view of the membrane  5  is illustrated showing the failure region  13  extending substantially around most of the circumference of the membrane, and the hinge region  14  extending along a short segment of the circumference. The reduced thickness regions of the membrane can be formed by heating, scoring or laser ablation. 
     Referring to  FIG. 1D , with the stopcock  10  closed, pressure is applied in the upper compartment by depressing the plunger. The applied pressure on the failure membrane  5  causes it to rupture at the failure region  13  and to bend at the hinge region  14 . The embolic particles and saline in the upper compartment  2  travel to the lower compartment  3  and mix with the contrast agent to form the mixed embolic composition  15 . Because the embolic particles are initially located in the upper compartment and the contrast in the lower compartment, the particles fall into the contrast solution in a turbulent manner which enhances mixing and the creation of a uniform suspension of the particles in the mixture. 
     Referring to  FIG. 1E , the stopcock  10  is opened to allow the mixed embolic composition  15  to pass via the connector  9 , through a catheter  16  for injection into the body (not shown). The plunger can be further lowered to apply pressure for injecting the mixture into the body. In other embodiments, the stopcock  10  can be eliminated where the flow resistance of the syringe outlet and any attached delivery apparatus, such as a catheter, is sufficient to retard flow of solution in response to the pressure in the syringe after rupturing the membrane. The plunger base  11 , particularly its circumference, may be made of a flexible rubbery material, such as an elastomeric polymeric material, that can deflect or bend when it engages the membrane so that the plunger can be lowered beyond the membrane into the lower compartment for injection of the mixture into the body. 
     Referring to  FIG. 2 , a syringe kit is illustrated. The kit includes a syringe barrel made of two detachable sections,  20  and  22 , defining the upper compartment  2  and the lower compartment  3 , a plunger  4  with a base  11 , a vial  24  of embolic material  7  in saline  8 , and a vial  26  of contrast agent  6 . The upper section  20  of the syringe apparatus has a female-type connector  21  at its bottom end to fit with a male-type connector  23  at the top of the lower section  22 . The connection between the upper and lower sections can be, for example, a pressfit, threaded or luer type connection. The lower section  22  has a connector  9  fitted with a stopcock  10 . Failure membrane  5  can be placed between the upper and lower sections or can be preattached to one of the sections; in  FIG. 2  the membrane is attached to the upper section. For use, the syringe apparatus is assembled as follows: Stopcock  10  is closed and contrast solution  6  from vial  26  is placed in the lower compartment  3  and the upper section is assembled with the lower section. Embolic material  7  along with saline solution  8  is placed in the upper compartment from vial  24 . The plunger  4  is then placed in the upper compartment to complete the syringe assembly. The syringe can be provided commercially as a kit with the compartments preloaded with the appropriate components. 
     Referring to  FIGS. 3A-3E , another embodiment of the syringe apparatus is illustrated. Here the failure membrane  30  is weakened across the center  31 , as illustrated in  FIG. 3B , for rupture on application of pressure. The rest of the syringe apparatus is as in the first embodiment illustrated in  FIG. 1 . Referring to  FIG. 3C , the stopcock  10  is closed, and when pressure is applied to the upper compartment by depressing the plunger  4 , the base  11  of the plunger conveys the applied pressure onto the failure membrane  30  causing its rupture at the weakened regions  31  (to form leaflets). The contents of the upper compartment  2  travel to the lower compartment  3  and mix with it to form the mixed embolic composition  15 . Because the embolic particles are initially located in the upper compartment and the contrast in the lower compartment, the particles fall into the contrast solution in a turbulent manner which enhances mixing and the creation of a uniform suspension of the particles in the mixture. Referring to  FIG. 3D , the plunger  4  is withdrawn, which causes the embolic composition  15  to backfill the upper compartment. This causes further mixing of the components of the embolic mixture and also prepares the apparatus for delivery of the embolic composition  15 . Referring to  FIG. 3E , stopcock  10  is opened and the plunger  4  is depressed to allow the embolic composition  15  to pass through the connector  9  to the catheter  16  for injection into the body (not shown). In other embodiments, the upper or lower compartments, or both upper and lower compartments can include a vent valve on the sidewall, (upper vent valve  33  shown in phantom in  FIG. 3A ) to enable pressure control within the syringe apparatus. 
     Referring to  FIG. 4A , in another embodiment, a syringe barrel  40  is provided that has parallel compartments, including a left compartment  41  with a plunger  42 , and a right compartment  43 , with a plunger  44 , both plungers  42  and  44  are fitted with a plunger lock  50 . The plunger locks  50  prevent accidental deployment of the plungers. An expanded view of the plunger lock is illustrated in  FIG. 4D . The plunger lock  50  includes a frame  54  consisting of a stationary vertical strip  56  placed towards one end of the frame and a movable vertical strip  57  placed towards the other end of the frame, with a threaded hole  58  at the center of the strip  57 , through which a screw  59  is passed. The space between the two strips  56  and  57  houses the stem of the plunger. In use, to lock the plunger and prevent its deployment, the strip  57  is moved until the stem of the plunger is tightly held between strips  56  and  57 . Counterclockwise movement of the screw  59  further secures the plunger tightly between the two strips  56  and  57 . To unlock the plunger for deployment, the screw  59  is turned clockwise and the strip  57  is moved away from the plunger which loosens the grip of the two strips  57  and  58  on the stem of the plunger and unlocks the plunger for deployment. The plunger locks can be made of a metallic or polymeric material. To place the plunger lock  50  on the stem of the plunger, the plunger lock  50  is unlocked, the strip  57  is moved towards the frame, and the lock is slid onto the stem of the plunger from the top and is placed in any desired position on the stem of the plunger. 
     The compartments are divided by a central divider  45  with a pressure-activated two-way valve  46  at the end of the central divider  45 , connecting the two compartments. The pressure-activated valve can include a polymer membrane  47  that can flex into either compartment based on the pressure differential between the compartments. A connector  48 , at the bottom of the syringe assembly communicates with both compartments of the syringe and is fitted with a stopcock  49 . The left compartment  41  contains the contrast solution  6 , and the right compartment  43  contains a mixture of embolic particles  7  and saline solution  8 . 
     Referring to  FIG. 4B , the stopcock  49  is closed, the two plunger locks  50  on the left and right plungers  42  and  44  are unlocked, and the right plunger  44  is lowered causing the membrane  47  to flex into the left compartment and the valve  46  to open. Embolic particles and saline travel to the left compartment (arrow) and mix with the contrast solution to form the embolic mixture  15 . Further thorough mixing may be achieved by repeated alternate operation of the two plungers,  42  and  44 . Referring to  FIG. 4C , the stopcock  49  is opened, the two plungers  42  and  44  are simultaneously depressed such that the embolic mixture  15  passes via the connector  48  through the catheter  16  for injection into the body (not shown). (Alternatively, the plungers can be depressed sequentially.) In other embodiments, the valve membrane can be a failure membrane. 
     Referring to  FIG. 5A  and  FIG. 5B , another embodiment of the syringe apparatus is illustrated. In this embodiment, there is no two-way valve connecting the two compartments. The central divider  45  extends up to the connector  48  at the bottom of the syringe assembly. Referring to  FIG. 5A , the left and right compartments  41  and  43  contain two different sizes of embolic particles, a smaller size  60 , and a larger size  62 , mixed with saline and/or contrast agent. Referring to  FIG. 5B , the left and right compartments  41  and  43  contain two different shapes, a spherical shape  64 , and an irregular shape  66 , of embolic particles mixed with saline and or contrast agent. The rest of the syringe apparatus is as in the embodiment described in  FIG. 4 . 
     The arrangement allows delivery of two different sizes of embolic particles sequentially or simultaneously by sequential or simultaneous operation of the plungers. For example, smaller particles can be delivered first to travel to smaller diameter vessels, followed by larger particles to occlude vessels of larger diameter, upstream of the small diameter vessels. Alternatively, two different shapes of embolic particles can be delivered sequentially (or simultaneously). For example, spherical particles may be delivered first to aggregate and occlude distal regions and the irregular particles may be delivered second for more proximal aggregation. 
     In use, embolic particles in saline are disposed in the compartments from the top of the syringe, after removing the plungers. Contrast agent is drawn into each compartment from a supply in communication with the connector  48  by releasing the appropriate plunger lock and withdrawing the appropriate plunger. The syringe can be provided commercially as a kit with the compartments preloaded with the appropriate components. For injection into the body, the embolic composition with the desired embolic particle size and shape is injected into the body by release of the appropriate plunger lock, opening the stopcock  49 , and depressing the appropriate plunger. 
     The mixing and delivery system discussed above can be used to deliver a number of compositions. Suitable embolic particles are polymer particles. Preferred particles are spherical particles formed of polyvinyl alcohol, as discussed in “Embolization”, U.S. Ser. No. 10/215,594, filed Aug. 9, 2002, the entire contents of which is incorporated herein by reference. A suitable contrast agent is Omnipaque 300 (Nycomed, Buckinghamshire, UK). (Omnipaque is an aqueous solution of iohexol, N.N.-Bis (2,3-dihydroxypropyl)-T-[N-(2,3-dihydroxypropyl)-acetamide]-2,4,6-trilodo-isophthalamide; Omnipaque 300 contains 647 mg of iohexol equivalent to 300 mg of organic iodine per ml). The syringe system can be used to premix and deliver other agents. For example, the systems can be used for mixing of drug agents, such as anti-cancer agents, with polymer particles as described in U.S. Ser. No. 10/232,265, filed Aug. 30, 2002. The system can be used to premix compositions without particles. A valve, such as in  FIG. 4A  can be used instead of the failure membrane in  FIG. 1A . A membrane can be used that is not pressure-activated. For example, the membrane can be deflected by a control lever operable from outside of the syringe barrel. In another example, a sharpened member can be located on the plunger head that pierces the membrane. 
     Still further embodiments are in the following claims.