Abstract:
The present invention relates to a container adapted to dispense its content under pressure. The container of the present invention consists of two separate compartments separated from one another by a slidable piston. The container of the present invention contains a haemostatic paste.

Description:
FIELD OF INVENTION 
       [0001]    The present invention relates to a container adapted to dispense its content under pressure. The container of the present invention consists of two separate compartments separated from one another by a slidable piston. The container of the present invention contains a haemostatic paste. 
       BACKGROUND OF INVENTION 
       [0002]    The use of haemostatic agents provides for control of bleeding in surgical procedures. Haemostatic agents, supplement pressure, ligature and other conventional methods of controlling capillary, venous and arterial bleeding are known. 
         [0003]    In the field of haemostatic control different devices for application of haemostatic agents are currently on the market. 
         [0004]    One such product (Surgiflo®) is a pre-filled syringe applied with an applicator tip. The syringe contains the haemostatic agent in paste form in a volume which allows suitable mixing of the haemostatic agent with any further agent, such as water, saline and thrombin, within the containment unit. Upon manual mixing of the haemostatic agent and the further agent a haemostatic paste is formed within the syringe. 
         [0005]    Only after such a haemostatic paste has been formed the user may then apply the paste to the site of bleeding. 
         [0006]    The design of the syringe leads to the need for applying manual pressure on the plunger located within the containment unit from behind leading to loss of some control with the direction in which the applicator tip is pointed, i.e. aiming correctly at the site of bleeding is made more difficult. 
         [0007]    Due to the viscosity of the haemostatic paste formed in the containment unit after mixing, the user has to apply considerable force to the end of the plunger in order to empty the haemostatic paste out of the containment unit onto a site of bleeding. 
         [0008]    Because such a relative high force is needed the precision in applying the product is limited and the device has limited user-friendliness. 
         [0009]    Accordingly there is a need for a device in the field of haemostatic control which in one easy-to-use-device provides a haemostatic paste to a site of bleeding directly from a sterile container with great precision and ease for the user. 
         [0010]    A vast range of materials are routinely dispensed from pressurized containers. Special containers exists which are able to keep the product out of contact with the propellant. There are generally speaking two types of these containers, “the collapsible bag” type and the “piston” type. The “collapsible bag” type comprises a collapsible bag arrangement where the product is held in a flexible bag secured to the neck of the container with an outlet valve. The propellant is held between the bag and the container wall. Under pressure the bag collapses and extrudes the product from the outlet valve. Filling of the bags is performed under high pressure through the valve which induces phase-separation in paste products. Additionally, filling of the product through the valve makes it possible to have residual paste maintained in the opening of the valve after the filling is completed. This residual paste would function as a plug of paste that would have to be removed prior to the use of the device. Also the opening of the valve is restricted which makes filling and especially emptying of the can difficult 
         [0011]    In the “piston” type the container is divided into two chambers by an internal piston, and product and propellant is held separately from each other with this piston. Under pressure of the propellant the piston forces the product from the container through a valve. 
         [0012]    The “piston” type containers are usually used for product in liquid, fluid, paste and plastic form, such as foodstuffs (mayonnaise, whipped cream etc.), cosmetics (dentifrice, shaving cream etc.), pharmaceuticals (ointment, rat poison etc.) and chemical products (sealant, adhesive etc.). 
       SUMMARY OF INVENTION 
       [0013]    The invention relates to a device for dispensing a haemostatic paste from a container under pressure having an interior including a product compartment and a propellant compartment separated from one another and a slidable piston separating the product compartment from the propellant compartment. 
         [0014]    This device provides haemostatic paste which may be administered with great precision and by use of a minimal amount of force. Preferably, the haemostatic paste is ready-to-use. In this context “ready-to-use” is intended to mean a paste that can be applied directly from the pressurized container to a subject. This does not exclude the possibility that further ingredients are mixed into the haemostatic paste after it has been expelled from the pressurized container. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0015]    In the field of haemostatic control it would be beneficial to be able to provide a haemostatic paste to a site of bleeding directly from a pressurized container with great precision and by use of a minimal amount of force by the user. With haemostatic pastes it is necessary to store the paste separately from the propellant intended to keep the paste under pressure. To do this, the paste is kept separate from the propellant by means of a piston capable of sliding in sealed contact against the interior surface of the body of the container. 
         [0016]    In order to obtain the required advantage of the piston, such a system requires that throughout the life of the device, that is from the first use to the last use, the pressure exerted by the propellant must be higher than the vapour pressure of the product. 
         [0017]    The invention relates to a device for dispensing a haemostatic paste from a container under pressure. 
         [0018]    In this way a sterile and facile administration of haemostatic paste is provided. Surgeons state that the present syringe type applicators require considerable force to apply, which compromises precision. This is overcome by the present invention which makes administration of the haemostatic paste easier by use of a propellant as driving force. The device of the invention is furthermore designed such that it can be pointed in all directions whilst complete emptying of the container is still possible. This is of high importance during a surgical procedure where the bleeding site may be located in difficult to reach places. As stated above previous products typically require considerable manual force for application to a bleeding site and the precise application of the haemostatic agent is difficult and requires some strength of the surgeon. 
         [0019]    The device of the present invention comprises a container having an interior including a product compartment and a propellant compartment separated from one another, said container having a first end with a haemostatic paste outlet extending from the product compartment, said outlet being openable and closable. A valve is located in communication with the first end of the product compartment. The valve may be positioned in connection with the haemostatic paste outlet to allow for flow of the haemostatic paste through the haemostatic paste outlet to the exterior of the device. A slidable piston is separating the product compartment from the propellant compartment. 
         [0020]    The piston may comprise a primary piston having a primary wall-engaging skirt and a secondary piston having a secondary wall-engaging skirt and between said primary and secondary pistons an interposed deformable sealant material is located. 
         [0021]    Under pressure said deformable material may be compressed between the primary and secondary pistons and urged against the container wall to form a seal. To ensure this function the primary piston is preferably in frictional engagement with the wall of the contained and the secondary piston is preferably in loose fit thus to encourage compression of the interposed deformable sealant material. This arrangement of the primary and secondary pistons make it possible to provide an efficient seal between the propellant chamber and the product chamber ensuring that the propellant is not mixed with the product at any time. 
         [0022]    The deformable sealant material may be any liquid or semi-solid material which is chemically compatible with the materials it will come into contact with in use. Water-based materials such as aqueous gels of alginic materials are suitable, as are many organic and mineral oils, greases and waxes. The sealant material may in one embodiment be selected from the group consisting of: ethylene glycol, diethylene glycol, butylene glycol, amylene glycol, glycerol, polyglycerin, glycerin, polyvinyl alcohol, silicone, acrylic resin. 
         [0023]    In one embodiment the deformable sealant material is a gel. In a more preferred embodiment the deformable sealant is an aqueous gel. 
         [0024]    The valve used with the present invention is preferably arranged to allow easy flow of the haemostatic paste through the haemostatic paste outlet and to allow the paste to be dispensed to exit via the valve. As the haemostatic pastes are viscous pastes the valve may be arranged with optimized fluid passage for example by having large inlet and/or out let openings, smooth surfaces and/or a passage way through which the paste may flow without being limited by bends, protrusions etc. 
         [0025]    In some advantageous embodiments the valve is furthermore fitted with an exchangeable, bendable and/or cutable long tip of the known type. For example such tips are used in conjunction with Surgiflo® haemostatic paste applicators. 
         [0026]    The exchangeable tip can be selected in order to allow administration of the haemostatic paste in hard to reach areas, to allow passage of a fluid with a specific viscosity and/or administer fluid at a specific flow rate. 
         [0027]    If a cutable long tip is provided the tip can be cut to a desired length with respect to given circumstances of the administration such as viscosity of fluid (haemostatic paste), administration area etc. If the long tip is at least partly conical the tip can be cut to provide a specific diameter to the exit opening of the tip. 
         [0028]    Alternatively a bendable tip is provided which holds its shape after being bent and preferably will not kink when being bend. The bendable tip can be bendable in all directions. 
         [0029]    Thus, the user may shape the tip to be optimized for administration of a specific fluid and/or optimized for administration of the fluid in hard to reach areas. For example the exchangeable tip may be bent to have an optimized curvature and a cut to have a desired length by the user. 
         [0030]    The tip is in one embodiment between 5-20 cm long, such as 10-20 cm long, such as 15-20 cm long. 
         [0031]    In one embodiment the tip is not bendable. 
         [0032]    This need for a controlled hold and movement is enhanced when a long tip is use such as the bendable tips mentioned above. This is due to the fact that any movements of the users hands may be enhanced at a distant tip. 
         [0033]    Preferably the device comprises a movable actuator coupled to the valving member so that actuating movement of the actuator actuates the valving member to the open position. For example the actuator may be of a form wherein a handle part of the actuator is positioned along the side of the container in a distance and angle from the container making it easy to reach and press by the user preferably with a minimal change of hand position. 
         [0034]    Further, the actuator may preferably be arranged to require a minimum of force by the user in order to actuate the valve and administer the haemostatic paste. This can for example be achieved by an actuator arrangement with a hinged lever arm transferring the force applied by the user to the movable valving member. When less force is required to actuate the valve the user is more likely to have a steady hand and is less likely to make any intentional movements with the device ensuring a reliable and optimal administration of the haemostatic paste. 
         [0035]    The pressure in the propellant chamber is in one embodiment in the range of 100-500 kPa at room temperature, more preferably in the range of 200-500 kPa, such as 300-500 kPa, more preferably 400-500 kPa. In another embodiment the pressure in the propellant chamber is in the range 100-400 kPa at room temperature, such as 100-300 kPa, more preferably 100-200 kPa. 
         [0036]    The propellant may be selected from the group consisting of nitrogen, oxygen, compressed air, butane, propane, chlorofluorocarbon, fluorocarbon and dimethyl ether. In a preferred embodiment the propellant is nitrogen, oxygen or compressed air. 
         [0037]    A brief description of the preferred method of filing and assembly of the device is described in Example 1. 
         [0038]    The haemostatic paste of the present invention has a viscosity in the range of 700-4.000 Pa·s at room temperature, such as between 1.000-4.000 Pa·s, for example 1.200-4.000 Pa·s, such as 1.400-4.000 Pa·s, for example 1.600-4.000 Pa·s, such as 1.800-4.000 Pa·s, for example 2.000-4.000 Pa·s, such as 2.200-4.000 Pa·s, for example 2.400-4.000 Pa·s, such as 2.600-4.000 Pa·s, for example 2.800-4.000 Pa·s, such as 3.000-4.000 Pa·s, for example 3.200-4.000 Pa·s, such as 3.400-4.000 Pa·s, for example 3.600-4.000 Pa·s, such as 3.800-4000 Pa·s 
         [0039]    In another embodiment of the present invention, the haemostatic paste of the present invention has a viscosity in the range 700-4.000 Pa·s, for example 700-3.800 Pa·s, such as 700-3.600 Pa·s, for example 700-3.400 Pa·s, such as 700-3.200 Pa·s, for example 700-3.000 Pa·s, such as 700-2.800 Pa·s, for example 700-2.600 Pa·s, such as 700-2.400 Pa·s, for example 700-2.200 Pa·s, such as 700-2.000 Pa·s, for example 700-1.800 Pa·s, such as 700-1.600 Pa·s, for example 700-1.400 Pa·s, such as 700-1.200 Pa·s, for example 700-1.000 Pa·s, such as 700-900 Pa·s, for example 700-800 Pa·s. 
         [0040]    The haemostatic paste of the present invention may comprise 10-25% v/v of gelatine or collagen and a suitable liquid. The suitable liquid may be selected from the group consisting of: sterile water, sterile saline and sterile PBS buffer. The haemostatic paste may be combined with another active ingredient. An appropriate amount of another active agent may be added to the haemostatic paste. Such another active agent may be selected from the group consisting of: germicidal agent, preservative, antimicrobial agents, coagulation factors, antifibrinolytic agents, surfactants, growth factors to promote healing, calcium ions to aid coagulation, adrenaline or other substances capable of constricting blood vessels. 
         [0041]    Specific examples of coagulation factors include coagulation factors selected from the group consisting of thrombin, fibrinogen, aprotinin, fibronectin, factor XIII, factor VII, factor VIII, and combinations thereof. Such compounds may be of any mammalian origin, such as of porcine or human origin, or may be obtained by recombinant means by methods well-known to the skilled person. It will be understood that gelatine and collagen are not considered as being coagulation factors. 
         [0042]    Antifibrinolytic agents may be selected from the group consisting of tranexamic acid, ε-aminocaproic acid, aprotinin, pepstatin, leupeptin, antipain, chymostatin, gabexate, and mixtures thereof. If present, the antifibrinolytic agent is preferably tranexamic acid. 
         [0043]    Antimicrobial agents may be selected from bactericidal or bacteriostatic agents, such as antibiotics and sulphonamides, antiviral compounds, antimycotic agents and anti-infectives. 
         [0044]    Surfactants may be selected from the group consisting of anionic surfactants, cationic surfactants, non-ionic surfactants and surface active biological modifiers. 
         [0045]    However, in a preferred embodiment of the invention, the composition does not contain such another active agent, i.e. said composition does not contain germicidal agent, coagulation factors, anti-fibrinolytic agents, surfactants, antimicrobial agents, preservative, growth factors, calcium ions, adrenaline and/or other substances capable of constricting blood vessels 
         [0046]    All ingredients of the haemostatic paste should be able to tolerate sterilization by radiation and still keep the activity. 
         [0047]    Within the device of the present invention, the haemostatic paste preferably has a minimum shelf-life of two years at room temperature. 
         [0048]    In use, the valve is opened releasing the internal pressure, the propellant in the propellant chamber expands thereby forcing the secondary piston into even closer contact with the sealant which is urged outward against the container wall. The primary piston advances and extrudes the product from the valve. 
         [0049]    It is preferred that the primary and secondary piston is preferably made of a plastic material selected from the group consisting of Polyethylene (HDPE), Polystyrene, Akrylnitril-butadien-styren (ABS), polyamide (PA), Polypropylene, and Poly Vinyl Chloride (PVC). Preferably the primary and secondary piston is made of HDPE. 
         [0050]    It is preferred that the container is made of aluminium coated on the inside with a coating. Such a coating may be selected from the group consisting of FDA approved coatings for example, but not limited to PPG2497-303/A (PPG Industries Lackfabrik GmbH), PPG2956-401/A (PPG Industries Lackfabrik GmbH) and J3121 (Valspar). 
         [0051]    The valve of the device may be fitted with an appropriate actuator. The pressure needed to be exerted by the user on the actuator in order to empty the device may vary with different actuator types. 
         [0052]    The device and all its components are preferably made of materials which can withstand sterilization by gamma radiation or beta radiation. Said sterilization is in one embodiment performed at 10-50 kGy, more preferably at 10-40 kGy, such as 10-30 kGy, more preferably 10-20 kGy. In another embodiment the sterilization is performed at 10-50 kGy, such at 20-50 kGy, more preferably 30-50 kGy, such as 40-50 kGy. In a preferred embodiment the sterilization is performed at 25-30 kGy. 
         [0053]    The device of the present invention is preferably completely air and light tight. After having subjected the device to sterilization by radiation the haemostatic paste present in the product chamber is sterile and will remain so until use. 
         [0054]    In the following the invention is described in further detail with reference to the drawings. However, all drawings are exemplary and are not to be construed as limiting to the invention. 
     
    
     
       DESCRIPTION OF DRAWINGS 
         [0055]      FIG. 1  shows the overall design of the device of the invention, 
           [0056]      FIG. 2  shows a preferred embodiment of the piston, and 
           [0057]      FIG. 3  shows an embodiment of an actuator used with the present invention. 
       
    
    
       [0058]    Referring to  FIGS. 1 and 2 , the device consists of an elongate cylindrical container  1  (which may be an extruded or seamed can) having a top  2  and inturned domed base  3 , the top having a neck  4  and fitted therein a valved outlet extrusion valve  5 . 
         [0059]    Within the container  1  there are, located serially from top to bottom, a primary piston  6 , a secondary piston  7  and a membrane partition  8 . Located between pistons  6  and  7  there is a mass of deformable sealant material  9 . These parts divide the internal volume of the container into a chamber  10  for the haemostatic paste to be dispensed and a chamber  11  for propellant. The presence of the membrane  8  is optional but, when present, it forms with the base  3  a propellant compartment  12 . The base  3  has a generally central hole for introduction of propellant during filling after which it is closed by a plug  13 . 
         [0060]    The crown of the primary piston  6  is shaped to conform generally to the internal configuration of the container top and internal parts of the valve  5  so as to maximise the amount of product which can be expelled by the piston. 
         [0061]    The base  3  of the container is domed and has a generally central hole for introduction of propellant during filing after which it is closed by a plug  13 . Said hole for filling of propellant can accordingly be opened and closed. 
         [0062]      FIG. 3  shows an embodiment of a movable actuator  4  used with the present invention. The actuator comprises a lever arm  15  connected to the haemostatic paste outlet of the device  16  by hinge  17  and a lever handle  18  extending from the lever arm  15  in an angle of approximately 90°. In the shown configuration the lever handle  17  is pressed towards the container  1  by a force indicated by arrow F and the valve is hereby opened allowing paste to pass from the inside of the container  1 , through the valve and out through a tip  19 . The force is provided by the grip of the user (not shown). 
         [0063]    When the force is released by the user, the lever arm  15  and handle  18  will move towards a relaxed state wherein the valve is closed. The movement of the lever handle  18  towards the relaxed position is indicated by arrow R. 
         [0064]    When the lever handle  18  is pressed by the user i.e. when the force F is applied by the user to open the valve, the lever handle is brought to a position in which it is parallel to or close to parallel to the longitudinal direction of the container. When the force is relaxed the handle moves back along the direction R. Thus, when the valve is closed the lever handle is relatively close to the container wall and is positioned in an angle which enables the user to easily change grip from holding around the container with all fingers to a grip holding around the lever handle with one or more fingers in order to apply the force F to actuate (i.e. open) the valve and administer the haemostatic paste until the force F is released. The tip  19  shown in  FIG. 3  is slightly conical at towards the distal end  20  of the tip. 
       EXAMPLES 
     Example 1 
       [0065]    Preparation of the Haemostatic Paste and Filling of the Device. 
         [0066]    Cross-linked gelatine powder is mixed with a liquid such that the powder is fully wetted. The paste is filled into the device of the invention through the top of the open container into the product compartment. In this way the product may be filled into the product compartment without the use of valves and without being under pressure. The container is closed by attaching the valve body to the container. The valve is securely sealed to the container by crimping of the valve body. Once the valve is sealed to the container the propellant is filled into the propellant compartment under pressure through the opening in the propellant compartment. The propellant compartment is then sealed by a plug, such as a rubber stopper.