Claims for Patent: 5,775,321

Summary for Patent: 5,775,321

Title:	Seal configuration for aerosol canister
Abstract:	A dual seal configuration for an aerosol canister containing a medicinal aerosol formulation. The canister includes a vial body and valve ferrule sealed by first and second sealing members to form a chamber that contains the medicinal aerosol formulation. The dual seal configuration reduces leakage of contents, and is particularly helpful where the formulation includes hydrofluorocarbon propellant and an ethanol cosolvent. The first seal can be selected to be a barrier to the formulation components, while the second seal can be relatively more labile to such components.
Inventor(s):	Alband; Todd D. (Eagan, MN)
Assignee:	Minnesota Mining and Manufacturing Company (St. Paul, MN)
Application Number:	08/361,719
Patent Claims:	1. An aerosol canister for containing a medicinal aerosol formulation, comprising: a vial body, a first seal, a second seal, and a valve ferrule, wherein the vial body has walls defining a vial opening, the valve ferrule occludes the vial opening, and the vial body, the first seal, and the valve ferrule define a chamber, and the valve ferrule and vial body are in opposing sealing engagement with each of the first and second seals, and wherein the first seal provides a barrier to one or more medicinal aerosol formulation components to which the second seal is more labile to said one or more formulation components than the first seal and wherein the ferrule comprises a cylindrical skirt that extends along the exterior or interior of the vial body or along a complementary radial skirt. 2. An aerosol canister according to claim 1, wherein the first seal comprises a thermoplastic elastomer comprising a copolymer of about 80 to about 95 percent ethylene and a total of about 5 percent to about 20 percent of one or more comonomers selected from the group consisting of 1-butene, 1-hexene, and 1-octene. 3. An aerosol canister according to claim 2, wherein the first seal further comprises talc in an amount effective to reduce and/or eliminate tack. 4. An aerosol canister according to claim 1, wherein the first seal comprises a styrene-ethylene/butylene-styrene copolymer. 5. An aerosol canister according to claim 1, wherein the chamber contains a medicinal aerosol formulation. 6. An aerosol canister according to claim 5, wherein the medicinal aerosol formulation comprises a propellant comprising 1,1,1,2-tetrafluoroethane or 1,1,1,2,3,3,3-heptafluoropropane. 7. An aerosol canister according to claim 6, wherein the medicinal aerosol formulation further comprises ethanol. 8. An aerosol canister according to claim 1, wherein the first seal comprises a thermoplastic elastomer comprising a copolymer of about 80 to about 95 percent ethylene and a total of about 5 percent to about 20 percent of one or more comonomers selected from the group consisting of 1-butene, 1-hexene, and 1-octene, or a thermoplastic elastomer comprising a styrene-ethylene/butylene-styrene copolymer, and wherein the first seal and the second seal are integral with one another. 9. An aerosol canister for containing a medicinal aerosol formulation, comprising: a vial body having exterior walls and an annular rim defining an opening, a valve ferrule having an annular gasket surface and a flange, a ferrule gasket, and an o-ring seal, wherein the gasket surface of the valve ferrule and the annular rim of the vial body are in opposing sealing engagement with the ferrule gasket, and the valve ferrule occludes the opening in the vial body to define a chamber, the flange of the valve ferrule extends along the exterior wall of the vial body, and the vial body and the flange are in opposing sealing engagement with the o-ring and wherein the ferrule comprises a cylindrical skirt that extends along the exterior or interior of the vial body or along a complementary radial skirt. 10. An aerosol canister according to claim 9, wherein the ferrule gasket comprises a thermoplastic elastomer comprising a copolymer of about 80 to about 95 percent ethylene and a total of about 5 percent to about 20 percent of one or more comonomers selected from the group consisting of 1-butene, 1-hexene, and 1-octene. 11. An aerosol canister according to claim 10, wherein the ferrule gasket further comprises talc. 12. An aerosol canister according to claim 9, wherein the ferrule gasket comprises a styrene-ethylene/butylene-styrene copolymer. 13. An aerosol canister according to claim 9, wherein the o-ring seal comprises nitrile rubber. 14. An aerosol canister according to claim 9, wherein the chamber contains a medicinal aerosol formulation. 15. An aerosol canister according to claim 14, wherein the medicinal aerosol formulation comprises a propellant comprising 1,1,1,2-tetrafluoroethane or 1,1,1,2,3,3,3-heptafluoropropane. 16. An aerosol canister according to claim 15, wherein the medicinal aerosol formulation further comprises ethanol. 17. An aerosol canister according to claim 1, wherein the second seal comprises neoprene, butyl rubber, or nitrile rubber. 18. An aerosol canister containing an HFC aerosol formulation, comprising: a vial body, a first seal, a second seal, and a valve ferrule, wherein the vial body has walls defining a vial opening, the valve ferrule occludes the vial opening, and the vial body, the first seal, and the valve ferrule define a chamber containing the aerosol formulation including a hydrofluorocarbon propellant, and wherein the valve ferrule and vial body are in opposing sealing engagement with each of the first and second seals. 19. The article of claim 18, wherein the hydrofluorocarbon is 1,1,1,2-tetrafluoroethane or 1,1,1,2,3,3,3-heptafluoropropane. 20. The article of claim 18, wherein the chamber further contains a polar cosolvent. 21. The article of claim 20, wherein the polar cosolvent is ethanol. 22. The article of claim 18, wherein the chamber further includes a medicament. 23. The article of claim 22, wherein the valve ferrule includes a metered dose valve. 24. The article of claim 18, wherein the first seal provides a barrier to one or more aerosol formulation components to which the second seal is more labile to said one or more formulation components than the first seal. 25. The article of claim 19, wherein the first seal includes a thermoplastic elastomer. 26. The article of claim 18, wherein the second seal includes a thermoset elastomer. 27. The article of claim 18, wherein the first seal comprises a copolymer of about 80 to about 95 percent ethylene and a total of about 5 percent to about 20 percent of one or more comonomers selected from the group consisting of 1-butene, 1-hexene, and 1-octene. 28. The article of claim 18, wherein the first seal comprises a styrene-ethylene/butylene-styrene copolymer. 29. The article of claim 18, wherein the first and second seals are both o-rings.