Methods of preparing a foam comprising a sclerosing agent

• US 20070003488A1
• Filed: 11/17/2004
• Published: 01/04/2007
• Est. Priority Date: 11/17/2003
• Status: Active Grant

• Current Assignee: Boston Scientific Medical Device Limited (Boston Scientific Corporation)
• Original Assignee: BTG International Limited (Boston Scientific Corporation)
• Inventors: Van Liew, Hugh, Kadar, Adil, Robinson, Nikki, Hodges, Garry, Wright, David, Harman, Anthony, Moggridge, Geoffrey
• Granted Patent: US 7,763,269 B2
• Time in Patent Office: Days
• US Class Current: 424/47
• CPC Class Codes: A61B 17/00008 Vein tendon strippers tube strippers A61M1/83
• CPC Class Codes: A61B 17/00491 Surgical glue applicators surgical adhesives A61L24/00; two-component delivery syringes A61M5/19
• CPC Class Codes: A61B 17/12022 Occluding by internal devices, e.g. balloons or releasable wires plugging an opening in the wall of an organ A61B17/0057; occluders for the cervical canal A61F6/146; vas deferens occluders A61F6/20
• CPC Class Codes: A61B 17/12109 in a blood vessel
• CPC Class Codes: A61B 17/12186 liquid materials adapted to be injected
• CPC Class Codes: A61B 2017/00495 for two-component glue
• CPC Class Codes: A61K 31/08 acyclic, e.g. paraformaldehyde
• CPC Class Codes: A61K 47/02 Inorganic compounds
• CPC Class Codes: A61K 47/10 Alcohols; Phenols; Salts thereof, e.g. glycerol; Polyethylene glycols [PEG]; Poloxamers; PEG/POE alkyl ethers
• CPC Class Codes: A61K 47/20 containing sulfur, e.g. dimethyl sulfoxide [DMSO], docusate, sodium lauryl sulfate or aminosulfonic acids
• CPC Class Codes: A61K 47/32 Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds, e.g. carbomers , poly(meth)acrylates, or polyvinyl pyrrolidone
• CPC Class Codes: A61K 9/0019 Injectable compositions; Intramuscular, intravenous, arterial, subcutaneous administration; Compositions to be administered through the skin in an invasive manner non-active ingredients are additionally classified in A61K47/00
• CPC Class Codes: A61K 9/08 Solutions composition of solutions A61K47/00
• CPC Class Codes: A61K 9/122 Foams; Dry foams edible foams A61K9/0056
• CPC Class Codes: A61K 9/124 characterised by the propellant
• CPC Class Codes: A61M 16/00 Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes stimulating the respiratory movement by mechanical, pneumatic or electrical means, iron lungs combined with gas breathing means A61H31/00
• CPC Class Codes: A61M 2202/00 Special media to be introduced, removed or treated
• CPC Class Codes: A61M 2210/086 Legs
• CPC Class Codes: A61M 2210/12 Blood circulatory system
• CPC Class Codes: A61M 5/178 Syringes
• CPC Class Codes: A61M 5/19 : having more than one chamber , e.g. including a manifold coupling two parallelly aligned syringes through separate channels to a common discharge assembly surgical glue applicators A61B17/00491
• CPC Class Codes: A61P 41/00 : Drugs used in surgical methods, e.g. surgery adjuvants for preventing adhesion or for vitreum substitution
• CPC Class Codes: A61P 43/00 : Drugs for specific purposes, not provided for in groups A61P1/00-A61P41/00
• CPC Class Codes: A61P 9/00 : Drugs for disorders of the cardiovascular system
• CPC Class Codes: A61P 9/14 : Vasoprotectives; Antihaemorrhoidals; Drugs for varicose therapy; Capillary stabilisers
• CPC Class Codes: B01F 23/235 : for making foam
• CPC Class Codes: B01F 25/4512 : with reciprocating pistons
• CPC Class Codes: B01F 25/4523 : the components being pressed through sieves, screens or meshes which obstruct the whole diameter of the tube
• CPC Class Codes: B01F 33/50112 : of the syringe or cartridge type
• CPC Class Codes: B65B 3/003 : Filling medical containers such as ampoules, vials, syringes or the like
• CPC Class Codes: B65B 31/00 : Packaging articles or materials under special atmospheric or gaseous conditions; Adding propellants to aerosol containers

Abstract

A therapeutic foam for the treatment of, inter alia, varicose veins comprises a sclerosing solution foamed with a physiological gas such as carbon dioxide, oxygen or a mixture thereof. The foam has a nitrogen content of less than 0.8%. It may be generated using a pressurised canister system incorporating a fine mesh of micron dimensions through which the gas and sclerosing liquid are passed to make the foam. Alternatively, the foam may be generated by passing gas and solution between two syringes through a fine mesh. Techniques are described for minimising the amount of nitrogen in a canister or syringe based product. A technique for generating and delivering foam simultaneously using a syringe based device is also disclosed.

Claims

1. A method of making a foam comprising

providing two syringes, wherein syringe one is charged with a liquid phase and syringe two is charge with a gas phase, syringe one is charge with the liquid phase and the gas phase, or both syringes are charged with the liquid phase and the gas phase;

and

transferring the liquid phase and the gas phase repeatedly between the syringes via a connector to form a foam, wherein

the liquid phase comprises at least one sclerosing agent and

the gas phase consisting essentially of gaseous nitrogen present in an amount ranging from 0.0001% to 0.8% by volume and at least one physiologically acceptable gas.

2. The method of claim 1, wherein the liquid phase and gas phase passing between the syringes is caused to pass through a mesh comprising apertures with a maximum dimension ranging from 1 to 200 micron.

3. The method of claim 2, wherein the maximum dimension ranges from 2 to 50 micron.

4. The method of claim 2, wherein the maximum dimension ranges from 3 and 20 micron.

5. The method of claim 1 wherein the gas phase is at least 70% by volume oxygen.

6. The method of claim 1, wherein the gas phase is at least 90% oxygen.

7. The method of claim 1, wherein the gas phase is at least 99% oxygen.

8. The method of claim 1, wherein the gas phase is substantially 100% oxygen.

9. A method of making a foam comprising:

(a) providing a syringe comprising a barrel, a first plunger and a second plunger, the second plunger having an apertured plunger head which is adapted to be movable within the barrel independently of the first plunger, the syringe being charged with a liquid phase and a gas phase; and

(b) oscillating the second plunger to form a foam;

wherein

the liquid phase comprises at least one sclerosing agent and

the gas phase consists essentially of gaseous nitrogen present in an amount ranging from 0.0001% to 0.8% by volume and at least one physiologically acceptable gas.

10. The method of claim 9, wherein the apertures in the second plunger have a maximum dimension ranging from 1 to 200 micron.

11. The method of claim 9, wherein the apertures in the second plunger have a maximum dimension ranging from 2 and 50 micron.

12. The method of claim 9, wherein the apertures in the second plunger have a maximum dimension ranging from 3 and 20 micron.

13. The method of claim 9, wherein the gas phase is at least 70% by volume oxygen.

14. The method of claim 9, wherein the gas phase is at least 90% oxygen.

15. The method of claim 9, wherein the gas phase is at least 99% oxygen.

16. The method of claim 9, wherein the gas phase is substantially 100% oxygen.

17. A sterile pack comprising:

(a) a syringe charged with at least one liquid sclerosing agent and a gas mixture consisting consists essentially of gaseous nitrogen present in an amount ranging from 0.0001% to 0.8% by volume and at least one other physiologically acceptable gas;

(b) a gas atmosphere inside the pack having substantially the same composition as the said gas mixture in the syringe.

18. The sterile pack of claim 17, wherein the gaseous nitrogen is present in an amount ranging from 0.001% to 0.8% by volume.

19. The sterile pack of claim 17, wherein the gaseous nitrogen is present in an amount ranging from 0.01% to 0.8% by volume.

20. The sterile pack of claim 17, wherein the gaseous nitrogen is present in an amount ranging from 0.01% to 0.7% by volume.

21. The sterile pack of claim 17, wherein the gaseous nitrogen is present in an amount ranging from 0.01% to 0.6% by volume.

22. The sterile pack of claim 17, wherein the at least one other physiologically acceptable gas is oxygen, carbon dioxide or a mixture thereof.