|Title:||Medicinal aerosol formulations|
|Abstract:||A self-propelling aerosol formulation which may be free from CFC's which comprises a medicament, 1,1,1,2-tetrafluoroethane, a surface active agent and at least one compound having a higher polarity than 1,1,1,2-tetrafluoroethane.|
|Inventor(s):||Purewal; Tarlochan S. (Leamington Spa, GB2), Greenleaf; David J. (Loughborough, GB2)|
|Assignee:||Riker Laboratories, Inc. (St. Paul, MN)|
1. An aerosol formulation comprising:
(a) a therapeutically effective amount of a medicament;
(b) a propellant substantially free of chlorofluorocarbons, said propellant comprising 1,1,1,2-tetrafluoroethane;
(c) a surface active agent in an amount sufficient (i) to stabilize the formulation or (ii) lubricate a valve stem in a metering valve; and
(d) at least one compound selected from the group consisting of ethyl alcohol, isopropyl alcohol, n-pentane, isopentane, neopentane, isopropyl, and myristate, said compound being present in an amount such that it is miscible with the 1,1,1,2-tetrafluoroethane and such that said surface active agent is soluble in the formulation in a greater amount than in 1,1,1,2-tetrafluoroethane.
2. The formulation of claim 1 wherein the weight ratio of 1,1,1,2-tetrafluoroethane to compound (d) is in the range of 50:50 to 99:1.
3. The formulation of claim 1 wherein said medicament is a member selected from the group consisting of salbutamol, beclomethasone dipropionate, disodium cromoglycate, pirbuterol, isoprenaline, adrenaline, rimiterol, and ipratropium bromide.