Claims for Patent: 6,739,333

Summary for Patent: 6,739,333

Title:	Stainless steel canister for propellant-driven metering aerosols
Abstract:	The present invention relates to corrosion resistant stainless steel canisters for propellant-containing aerosol forumlations for use in propellant gas-operated inhalers.
Inventor(s):	Hoelz; Hubert (Oberheimbach, DE), Lostritto; Richard Thomas (Gaithersburg, MD), Nagel; Juergen (Bad Kreuznach, DE), Vega; Julio Cesar (Buenos Aires, AR)
Assignee:	Boehringer Ingelheim Pharma KG (Ingelheim, DE)
Application Number:	09/580,246
Patent Claims:	1. A metered-dose inhaler having a metal cannister to hold drug and non-CFC propellant gas, comprising the following alloy forming walls of the cannister: Iron comprising about 40.0 to about 53.0%, Nickel comprising about 23.0 to about 28.0%, Chromium comprising about 19.0 to about 23.0%, Molybdenum of about 4.0 to about 5.0%, Manganese of about 0.0 to about 2.0%, Copper of about 1.0 to about 2.0%, Silicon of about 0.0 to about 1.0%, Phosphorous of about 0.0 to about 0.045%, Sulfur of about 0.0 to about 0.035% and Carbon of about 0.0 to about 0.020%. 2. The metered-dose inhaler as recited in claim 1, wherein the alloy is as follows: Chromium about 19.0 to about 21.0%, Nickel about 24.0 to about 26.0%, Molybdenum about 4.0 to about 5.0%, Copper about 1.0 to about 2.0%, Manganese about 0.0 to about 2.0%, Silicon about 0.0 to about 0.5%, Carbon about 0.0 to about 0.02% and remainder Iron. 3. The metered-dose inhaler as recited in claim 1, wherein the cannister comprises a container and a valve cup with a valve embedded therein, the container constituting walls of the cannister. 4. The metered-dose inhaler as recited in claim 3, wherein the valve cup is aluminum and is sealed with a gasket relative to the interior of the container. 5. The metered-dose inhaler as recited in claim 3, wherein the valve contains one or more stainless steel springs, a valve stem, a metering chamber and a valve body, wherein one or more of the valve stem, the metering chamber and the valve body are made of material selected from steel, the alloy used for forming walls of the cannister and a plastic. 6. The metered-dose inhaler as recited in claim 5, wherein the springs are made of stainless steel, and the valve stem, the metering chamber and the valve body are made of polybutylene terephthalate. 7. The metered-dose inhaler as recited in claim 5, wherein the valve stem is sealed off from the valve cup by a gasket or gaskets. 8. The metered-dose inhaler as recited in claim 7, wherein the gasket or gaskets are made from ethylene/propylene/diene terpolymer. 9. The metered-dose inhaler as recited in claim 5, wherein the valve cup is made from the alloy used to form the container. 10. The metered-dose inhaler as recited in claim 1, wherein walls of the canister can withstand a bursting pressure of more than 30,000 hPa. 11. The metered-dose inhaler as recited in claim 10, wherein walls of the cannister can withstand a bursting pressure of more than 100,000 hPa. 12. The metered-dose inhaler as recited in claim 10, wherein walls of the cannister can withstand a bursting pressure of more than 200,000 hPa. 13. The metered-dose inhaler as recited in claim 1, wherein walls of the cannister are about 0.1 to about 0.5 mm thick. 14. The metered-dose inhaler as recited in claim 13, wherein walls of the cannister are about 0.15 to about 0.35 mm thick. 15. The metered-dose inhaler as recited in claim 14, wherein walls of the cannister are about 0.19 to about 0.30 mm thick. 16. A metered-dose inhaler according to claim 1, wherein the cannister contains a formulation comprising a fluorohydrocarbon propellant. 17. A metered-dose inhaler according to claim 16, wherein the fluorohydrocarbon propellant is selected from 1,1,1,2-tetrafluoroethane and 1,1,1,2,3,3,3-heptafluoropropane. 18. A metered-dose inhaler according to claim 16, wherein the formulation further comprises one or more electrolytes. 19. A metered-dose inhaler according to claim 16, wherein the formulation further comprises one or more acids. 20. A metered-dose inhaler according to claim 16, wherein the formulation further comprises ethanol. 21. A metered-dose inhaler having a metal cannister to hold drug and non-CFC propellant gas, comprising the following alloy forming walls of the cannister: Iron about 60.0 to about 72.0%, Nickel about 9.0 to about 13.0%, Chromium about 17.0 to about 21.00%, Molybdenum about 2.0 to about 3.0%, Manganese about 0.0 to about 1.5%, Silicon about 0.0 to about 1.5%, Phosphorous about 0.0 to about 0.04%, Sulfur about 0.0 to about 0.04% and Carbon about 0.0 to about 0.03%. 22. The metered-dose inhaler as recited in claim 21, wherein the cannister comprises a container and a valve cup with a valve embedded therein, the container constituting walls of the cannister. 23. The metered-dose inhaler as recited in claim 22, wherein the valve cup is aluminum and is sealed with a gasket relative to the interior of the container. 24. The metered-dose inhaler as recited in claim 22, wherein the valve contains one or more stainless steel springs, a valve stem, a metering chamber and a valve body, wherein one or more of the valve stem, the metering chamber and the valve body are made of material selected from steel, the alloy used for forming walls of the cannister and a plastic. 25. The metered-dose inhaler as recited in claim 24, wherein the springs are made of stainless steel, and the valve stem, the metering chamber and the valve body are made of polybutylene terephthalate. 26. The metered-dose inhaler as recited in claim 24, wherein the valve stem is sealed off from the valve cup by a gasket or gaskets. 27. The metered-dose inhaler as recited in claim 26, wherein the gasket or gaskets are made from ethylene/propylene/diene terpolymer. 28. The metered-dose inhaler as recited in claim 24, wherein the valve cup is made from the alloy used to form the container. 29. The metered-dose inhaler as recited in claim 21, wherein walls of the canister can withstand a bursting pressure of more than 30,000 hPa. 30. The metered-dose inhaler as recited in claim 29, wherein walls of the cannister can withstand a bursting pressure of more than 100,000 hPa. 31. The metered-dose inhaler as recited in claim 29, wherein walls of the cannister can withstand a bursting pressure of more than 200,000 hPa. 32. The metered-dose inhaler as recited in claim 21, wherein walls of the cannister are about 0.1 to about 0.5 mm thick. 33. The metered-dose inhaler as recited in claim 32, wherein walls of the cannister are about 0.15 to about 0.35 mm thick. 34. The metered-dose inhaler as recited in claim 33, wherein walls of the cannister are about 0.19 to about 0.30 mm thick. 35. A metered-dose inhaler according to claim 21, wherein the cannister contains a formulation comprising a fluorohydrocarbon propellant. 36. A metered-dose inhaler according to claim 35, wherein the fluorohydrocarbon is selected from 1,1,1,2-tetrafluoroethane and 1,1,1,2,3,3,3-heptafluoropropane. 37. A metered-dose inhaler according to claim 35, wherein the formulation further comprises one or more electrolytes. 38. A metered-dose inhaler according to claim 35, wherein the formulation further comprises one or more acids. 39. A metered-dose inhaler according to claim 35, wherein the formulation further comprises ethanol. 40. A metered-dose inhaler having a metal cannister to hold drug and non-CFC propellant gas, comprising the following alloy forming walls of the cannister: Chromium about 16.5 to about 18.5%, Nickel about 11.0 to about 14.0%, Molybdenum about 2.0 to about 2.5%, Carbon about 0.0 to about 0.03% and remainder Iron. 41. The metered-dose inhaler as recited in claim 40, wherein the cannister comprises a container and a valve cup with a valve embedded therein, the container constituting walls of the cannister. 42. The metered-dose inhaler as recited in claim 41, wherein the valve cup is aluminum and is sealed with a gasket relative to the interior of the container. 43. The metered-dose inhaler as recited in claim 41, wherein the valve contains one or more stainless steel springs, a valve stem, a metering chamber and a valve body, wherein one or more of the valve stem, the metering chamber and the valve body are made of material selected from steel, the alloy used for forming walls of the cannister and a plastic. 44. The metered-dose inhaler as recited in claim 43, wherein the springs are made of stainless steel, and the valve stem, the metering chamber and the valve body are made of polybutylene terephthalate. 45. The metered-dose inhaler as recited in claim 43, wherein the valve stem is sealed off from the valve cup by a gasket or gaskets. 46. The metered-dose inhaler as recited in claim 45, wherein the gasket or gaskets are made from ethylene/propylene/diene terpolymer. 47. The metered-dose inhaler as recited in claim 43, wherein the valve cup is made from the alloy used to form the container. 48. The metered-dose inhaler as recited in claim 40, wherein walls of the canister can withstand a bursting pressure of more than 30,000 hPa. 49. The metered-dose inhaler as recited in claim 48, wherein walls of the cannister can withstand a bursting pressure of more than 100,000 hPa. 50. The metered-dose inhaler as recited in claim 48, wherein walls of the cannister can withstand a bursting pressure of more than 200,000 hPa. 51. The metered-dose inhaler as recited in claim 40, wherein walls of the cannister are about 0.1 to about 0.5 mm thick. 52. The metered-dose inhaler as recited in claim 51, wherein walls of the cannister are about 0.15 to about 0.35 mm thick. 53. The metered-dose inhaler as recited in claim 52, wherein walls of the cannister are about 0.19 to about 0.30 mm thick. 54. A metered-dose inhaler according to claim 40, wherein the cannister contains a formulation comprising a fluorohydrocarbon propellant. 55. A metered-dose inhaler according to claim 54, wherein the fluorohydrocarbon is selected from 1,1,1,2-tetrafluoroethane and 1,1,1,2,3,3,3-heptafluoropropane. 56. A metered-dose inhaler according to claim 54, wherein the formulation further comprises one or more electrolytes. 57. A metered-dose inhaler according to claim 54, wherein the formulation further comprises one or more acids. 58. A metered-dose inhaler according to claim 54, wherein the formulation further comprises ethanol.