Claims for Patent: 6,558,651

Summary for Patent: 6,558,651

Title:	Aerosols containing annealed particulate salbutamol and tetrafluoroethane
Abstract:	This invention relates to aerosol formulations of use for the administration of medicaments by inhalation. More particularly, the invention relates to a pharmaceutical aerosol formulation which comprises particulate salbutamol sulphate having a crystalline form in which the outer layer of the crystals is substantially non-amorphous; and 1,1,1,2-tetrafluoroethane. A method of treating respiratory disorders which comprises administration by inhalation of an effective amount of a pharmaceutical aerosol formulation as defined is also described.
Inventor(s):	Riebe; Michael Thomas (Raleigh, NC), Dwivedi; Sarvajna Kumar (San Diego, CA), Li-Bovet; Li (Scotch Plains, NJ)
Assignee:	SmithKline Beecham Corporation (Philadelphia, PA)
Application Number:	09/091,496
Patent Claims:	1. A pharmaceutical aerosol formulation comprising: annealed particulate salbutamol sulphate; and a propellant comprising 1,1,1,2-tetrafluoroethane. 2. A pharmaceutical aerosol formulation comprising: annealed particulate salbutamol sulphate, wherein the annealed particulate is substantially thermally inactive as measured by microcalorimetry at about 25.degree. C. and between about 30% to about 90% relative humidity; and a propellant comprising 1,1,1,2-tetraflouroethane. 3. The pharmaceutical aerosol formulation of claim 1, wherein the annealed particulate salbutamol sulphate is micronized and includes a recrystallized outer surface layer. 4. A pharmaceutical aerosol formulation comprising: annealed particulate salbutamol sulphate having a water content of less than about 0.4% by weight; and propellant comprising 1,1,1,2-tetrafluoroethane. 5. The formulation of claim 4, wherein said annealed particulate salbutamol sulphate has a water content of less than about 0.35% by weight. 6. The formulation of claim 5, wherein said annealed particulate salbutamol sulphate has a water content of less than about 0.3% by weight. 7. The formulation of claim 1, wherein said annealed particulate salbutamol sulphate is present in an amount from 0.01% to 1% w/w. 8. The formulation claim 1, wherein said annealed particulate salbutamol sulphate is present in an amount from 0.05 to 0.2% w/w. 9. A pharmaceutical aerosol formulation consisting essentially of: annealed particulate salbutamol sulphate; and a propellant comprising 1,1,1,2-tetrafluoroethane. 10. A canister suitable for delivering a pharmaceutical aerosol formulation comprising: a container capable of withstanding the vapour pressure of a propellant comprising 1,1,1,2-tetrafluoroethane, a metering valve for containing the propellant in the container; and within the container, the pharmaceutical aerosol formulation comprising annealed particulate salbutamol sulphate and the propellant. 11. The canister of claim 10 wherein the container is a metal can. 12. The canister of claim 10, wherein the container is an aluminum can having internal surfaces, and wherein the internal surfaces are coated with a coating comprising a fluorocarbon polymer. 13. A metered dose inhaler comprising: a container adapted to contain a pharmaceutical aerosol formulation; in the container the pharmaceutical aerosol formulation comprising annealed particulate salbutamol sulphate and 1,1,1,2-tetrafluoroethane; and metering means for metering the aerosol formulation. 14. A method of treating respiratory disorders comprising: providing a pharmaceutical aerosol formulation comprising annealed particulate salbutamol sulphate and 1,1,1,2-tetrafluoroethane; and administering by inhalation of treatment effective amount of the pharmaceutical aerosol formulation. 15. A pharmaceutical aerosol formulation made by the steps comprising: providing crystalline particulate salbutamol sulphate, annealing the crystalline particulate salbutamol sulphate by subjecting said particulate salbutamol sulphate to a temperature of between about 0.degree. C. to about 100.degree. C. with a relative humidity of between about 20% to about 90% to produce annealed particulate salbutamol sulphate; and combining the annealed particulate salbutamol sulphate with a propellant comprising 1,1,1,2-tetrafluoroethane. 16. A pharmaceutical aerosol formulation made by the steps comprising: providing crystalline particulate salbutamol sulphate; annealing the crystalline particulate salbutamol sulphate by heating said particulate salbutamol under a vacuum to produce annealed particulate salbutamol sulphate; and combining the annealed particulate salbutamol sulphate with a propellant comprising 1,1,1,2-tetrafluoroethane.