Therapeutic foam

• US 20070003489A1
• Filed: 05/13/2005
• 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: Wright, David, Harman, Anthony, Kadar, Adil, Robinson, Nikki, Hodges, Garry
• Granted Patent: US 8,048,439 B2
• Time in Patent Office: Days
• US Class Current: 424/47
• CPC Class Codes: A61K 9/122 Foams; Dry foams edible foams A61K9/0056

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 foam comprising a liquid phase and a gas phase 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, Xenon gas in an amount greater than 5% and at least one physiologically acceptable gas other than Xenon.

3. The foam of claim 1 or claim 2, wherein the gaseous nitrogen is present in an amount ranging from 0.001% to 0.8%.

4. The foam of claim 1 or claim 2, wherein the gaseous nitrogen is present in an amount ranging from 0.01% to 0.8%.

5. The foam of claim 1 or claim 2, wherein the gaseous nitrogen is present in an amount ranging from 0.01% to 0.7%.

6. The foam of claim 1 or claim 2, wherein the gaseous nitrogen is present in an amount ranging from 0.01% to 0.6%.

7. The foam of claim 1 or claim 2, wherein the at least one other physiologically acceptable gas is chosen from oxygen, carbon dioxide and mixtures thereof.

8. The foam of claim 1 or claim 2, wherein the foam has a density less than 0.25 g/cm and half life of greater than 100 secs.

9. The foam of claim 1 or claim 2, wherein the half life is at least 120 seconds.

10. The foam of claim 1 or claim 2, wherein the half life is at least 150 seconds.

11. The foam of claim 1 or claim 2, wherein the half life is at least 180 seconds.

12. The foam of claim 1 or claim 2, wherein the density ranges from 0.07 to 0.22 g/ml.

13. The foam of claim 1 or claim 2, wherein the density ranges from 0.07 to 0.19 g/ml.

14. The foam of claim 1 or claim 2, wherein the density ranges from 0.07 to 0.16 g/ml.

15. The foam of claim 1 or claim 2, wherein the density ranges from 0.08 to 0.14 g/ml.

16. The foam of claim 1 or claim 2, wherein the at least one sclerosing agent is chosen from polidocanol, glycerol and sodium tetradecyl sulphate.

17. The foam of claim 1 or claim 2, wherein the at least one sclerosing agent is polidocanol.

18. The foam of claim 1 or claim 2, wherein the polidocanol is present in a concentration ranging from 0.5 to 4% vol/vol in the liquid phase.

19. The foam of claim 1, wherein Xenon gas is present in an amount greater than 20%.

20. The foam of claim 1, wherein Xenon gas is present in an amount greater than 50%.

21. The foam of claim 1, wherein Xenon gas is present in an amount greater than 75%.

33. A method for angiologic treatment comprising injecting the foam as described in claim 1 or claim 2 into vessels to be treated.

34. The method of claim 33 comprising having a patient breathe oxygen or an oxygen enriched atmosphere for a predetermined period prior to injecting the foam.

2. A foam comprising a liquid phase and a gas phase 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 Xenon gas.

35. The method for phlebologic treatment comprising injecting the foam as described in clam 1 or claim 2 into vessels to be treated.

36. The method of claim 35 comprising having a patient breathe oxygen or an oxygen enriched atmosphere for a predetermined period prior to injecting the foam.

37. The method of claim 36, wherein substantially the entire greater saphenous vein of one leg of a human patient is treated by a single injection of foam.

38. The method of claim 37, wherein the single injection uses an amount ranging from 10 ml and 50 ml.

39. The method of claim 38, wherein the single injection uses an amount ranging from 10 ml and 40 ml.

40. The method of claim 39, wherein the single injection uses an amount ranging from 15 ml and 30 ml.

22. A canister, the contents of which consist of a liquid component and a gas component, maintained at above atmospheric pressure, 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 Xenon gas in an amount greater than 5% and at least one physiologically acceptable gas other than Xenon, or alternatively the gas phase consisting essentially of gaseos nitrogen present in an amount ranging from 0.0001% to 0.8% and Xenon gas.

23. The canister of claim 22, further comprising a foam generating element with at least one aperture formed therein, the at least one aperture having maximum dimensions ranging from 0.1 to 200 micron.

24. The canister of claim 23, wherein the at least one aperture has maximum dimensions ranging from 1 to 50 micron.

25. The canister of claim 24, wherein the at least one aperture has maximum dimensions ranging from 2 to 30 micron.

26. The canister of claim 25, wherein the at least one aperture has maximum dimensions ranging from 3 to 10 micron.

27. The canister of claim 26, wherein the at least one aperture has maximum dimensions of about 5 micron.

28. The canister of claim 24, wherein the at least one aperture has a maximum dimension of 3 to 10 micron, and wherein the at least one other physiologically acceptable gas is from 1 to 40% carbon dioxide and the remaining gas is substantially oxygen.

29. The canister of claim 24, wherein the at least one other physiologically acceptable gas is from 10 and 30% carbon dioxide gas and the remaining gas is substantially oxygen.

30. A method of making a canister of claim 22 comprising:

(a) flushing the canister with a gas essentially comprising Xenon or a mixture of Xenon and the said other physiological acceptable gas;

(b) introducing the at least one sclerosing agent sclerosing agent into the canister either before or after step (a);

(c) pressurising the canister to a first predetermined pressure above atmospheric pressure from a source of Xenon and/or a source of the said other physiological acceptable gas whose level of nitrogen contamination is between 0.0001% and 0.5%.

31. The method of claim 30, further comrising the step of partially exhausting the contents of the canister, followed by re-pressurising the canister from the same or a different source or sources of gas whose level of nitrogen contamination is between 0.0001% and 0.5%.

32. The method of claim 30, wherein the pressure in the canister is maintained at or above the surrounding atmospheric pressure.