Container for the generation of therapeutic microfoam

Abstract

The device containing sclerosant liquid for use in the treatment of blood vessles comprises an aerosol valve housing mounted on a canister having an expandable inner container in which the sclerosant fluid is contained, wherein the expandable inner container is affixed to the outer opening of the canister or to the aerosol valve housing, whereby the introduction of pressurised gas through the aerosol valve causes the expandable inner container to inflate to accommodate the pressurised gas.

1 . A device containing sclerosant liquid for use in the treatment of blood vessels comprising an aerosol valve housing mounted on a canister having an expandable inner container in which the sclerosant fluid is contained, wherein the expandable inner container is affixed to the outer opening of the canister or to the aerosol valve housing, whereby the introduction of pressurised gas through the aerosol valve causes the expandable inner container to inflate to accommodate the pressurised gas. 
     
     
         2 . A device according to  claim 1  wherein the sclerosant liquid contained therein may be mixed with a pressurised gas comprising a physiologically acceptable blood dispersible gas to produce a sclerosing foam. 
     
     
         3 . A device according to  claim 1  wherein the physiologically acceptable blood dispersible gas is stored in a separate container prior to use. 
     
     
         4 . A device according to  claim 1  wherein mixing of gas and aqueous sclerosant occurs inside the aerosol valve at the mouth of the expandable inner container. 
     
     
         5 . A device according to  claim 1  comprising a canister, an expandable inner container affixed to the outer opening of the canister or to the aerosol valve housing above the gas-entry ports of the valve, a solution of the sclerosing agent in a physiologically acceptable solvent, a pathway with one or more outlet orifices by which the solution may pass from the expandable inner container to the exterior of the device through said one or more outlet orifices and a mechanism by which the pathway from the inner container to the exterior can be opened or closed such that, when the container is pressurised and the pathway is open, a gas-solution mixture will be forced along the pathway and through the one or more outlet orifices, said canister incorporating an inlet for the admission of a pressurised source of physiologically acceptable gas that is dispersible in blood; the gas being in contact with the solution on activation of the mechanism such as to produce the gas-solution mixture; said pathway to the exterior of the canister including one or more foaming elements; and the blood-dispersible gas is stored in a container provided with engaging means for the canister holding the aqueous sclerosant liquid. 
     
     
         6 . A device for producing a microfoam suitable for use in scleropathy of blood vessels, comprising an aerosol valve housing mounted on a canister, an expandable inner container affixed to the outer opening of the canister or to the aerosol valve housing, whereby the introduction of pressurised gas through the aerosol valve causes the expandable inner container to inflate to accommodate the pressurised gas, a pathway with one or more outlet orifices by which the solution may pass from the inner container to the exterior of the device through said one or more outlet orifices and a mechanism by which the pathway from the inner to the exterior can be opened or closed such that, when the container is pressurised and the pathway is open, a gas-solution mixture will be forced along the pathway and expelled through the one or more outlet orifices;
 said canister incorporating an inlet for the admission of a pressurised source of physiologically acceptable gas that is dispersible in blood; the gas being in contact with the solution on activation of the mechanism such as to produce the gas-solution mixture;   said pathway to the exterior of the device including one or more foaming elements.   
     
     
         7 . A device according to  claim 6  wherein the expandable inner container contains a solution of the sclerosing agent. 
     
     
         8 . A device according to  claim 7  wherein the solution of the scleorsing agent is mixed with physiologically acceptable gas in a predetermined proportion. 
     
     
         9 . A device according to  claim 1  wherein the expandable inner container comprises a flexible, expandable substantially gas-impermeable material. 
     
     
         10 . A device according to  claim 8  wherein the expandable inner container is in the form of a pleated bag. 
     
     
         11 . A device according to  claim 10  wherein the expandable inner container comprises metal or metallised foil. 
     
     
         12 . A device according to  claim 1  wherein the device includes a mechanism to reduce the pressure inside the canister and permit full expansion of the expandable inner container. 
     
     
         13 . A device according to  claim 12  wherein the mechanism comprises a vent in the canister. 
     
     
         14 . A device according to  claim 13  wherein the vent is sealed during storage and is opened prior to use. 
     
     
         15 . A device for producing a microfoam suitable for use in scleropathy of blood vessels, in the form of a kit comprising:
 (a) a device comprising an aerosol valve housing mounted on a canister having an expandable inner container containing an aqueous solution of the sclerosing agent affixed to the outer opening of the canister, or to the aerosol valve housing, whereby the introduction of pressurised gas through the aerosol valve causes the expandable inner container to inflate to accommodate the pressurised gas; a pathway with one or more outlet orifices by which the solution may pass from a pressurisable chamber to the exterior of the device through said one or more outlet orifices; and a mechanism by which the pathway from the chamber to the exterior can be opened or closed such that, when the container is pressurised and the pathway is open, a gas-solution mixture will be forced along the pathway and through the one or more outlet orifices; and   (b) a pressurised container containing a physiologically acceptable blood-dispersible gas;   said canister incorporating an inlet for the admission of blood-dispersible gas; the gas being in contact with the solution on activation of the mechanism such as to produce the gas-solution mixture.   
     
     
         16 . A device according to  claim 15  wherein a foaming element or elements is provided having one or more passages mounted such that the gas-liquid mixture passes through the passage or passages and is caused to foam. 
     
     
         17 . A device according to  claim 16  wherein the foaming element(s) comprises one or more passages of cross sectional dimension 0.1 μm to 30 μm, through which the gas-liquid mixture is passed to reach the exterior of the device, said passing of said mixture through the passages forming a microfoam of from 0.07 to 0.19 g/ml density and of half-life at least 2 minutes. 
     
     
         18 . A device comprising a canister containing a storage gas and a pressurisable inner container containing a sclerosant liquid for use in the treatment of blood vessels, wherein the sclerosant liquid and storage gas are maintained in isolation through separation on opposite sides of a movable barrier. 
     
     
         19 . A device according to  claim 18  wherein the storage gas is an inert gas or atmospheric gas adjacent to or surrounding the pressurisable inner container. 
     
     
         20 . A device according to  claim 18  wherein the sclerosant liquid contained therein may be mixed with a pressurised gas comprising a physiologically acceptable blood dispersible gas to produce a sclerosing foam. 
     
     
         21 . A device according to  claim 20  wherein the physiologically acceptable blood dispersible gas is stored in a separate container prior to use. 
     
     
         22 . A device according to  claim 1  wherein the sclerosant liquid is a solution of polidocanol or sodium tetradecyl sulfate in an aqueous carrier. 
     
     
         23 . A device containing sclerosant liquid for use in the treatment of blood vessels comprising an aerosol valve housing and an expandable container in which the sclerosant fluid is contained, wherein the expandable container is affixed to the aerosol valve housing, whereby the introduction of pressurised gas through the aerosol valve causes the expandable container to inflate to accommodate the pressurised gas. 
     
     
         24 . A method for producing a sclerosing foam comprising introducing a pressurised physiologically acceptable blood dispersible gas into an expandable container in which sclerosant fluid is contained, wherein the introduction of said gas causes the container to inflate; and releasing the resulting gas-sclerosant mixture from the container to form a sclerosing foam. 
     
     
         25 . A method according to  claim 24  wherein the expandable container is affixed to the outer opening of an aerosol canister or to an aerosol valve housing. 
     
     
         26 . A method according to  claim 24  wherein the pressurised gas is introduced through the aerosol valve. 
     
     
         27 . A method according to  claim 24  wherein mixing of the gas-sclerosant mixture occurs inside an aerosol valve at the mouth of the expandable container. 
     
     
         28 . A method according to  claim 24  wherein the pressurised gas is stored in a separate container prior to use. 
     
     
         29 . A method according to  claim 24  wherein the gas-sclerosant mixture is released through a foaming element or elements such that the gas-sclerosant mixture passes through the passage or passages in the foaming element and is caused to foam and wherein the foam produced is a microfoam. 
     
     
         30 . A method for producing a microfoam suitable for use in scleropathy of blood vessels, comprising introducing pressurised physiologically acceptable blood dispersible gas into a device containing sclerosant solution contained in an expandable inner container, wherein the gas is introduced into the container through an aerosol valve causing the container to inflate; and passing the resulting pressurised gas-solution mixture from the inner container through a pathway to the exterior of the device, the pathway including one or more foaming elements, such that a scleorsing microfoam is produced.