Medicaments for asthma treatment

Abstract

A method and apparatus are disclosed for treating asthma and other respiratory conditions. A medicament comprising a surface active phospholipid (SAPL) is prepared in the form of a fine powder and administered to the lungs in a gas stream. A preferred SAPL is a solid blend of diplamitoyl choline and phosphatdiyl glycerol (PG).

1 . Use of a surface active phospholipid (SAPL) composition in the preparation of a medicament for the treatment of asthma by administration of the medicament to the patient's airways, said medicament comprising SAPL and containing a component capable of binding to the surface of lung tissue and said medicament being in finely divided solid form.  
     
     
         2 . Use as claimed in  claim 1  wherein the medicament is a finely-divided dry powder having a particle size distribution such that it can be introduced into the airways by carriage in a gas stream.  
     
     
         3 . Use as claimed in  claim 2  wherein the gas stream comprises a halocarbon which is gaseous at ambient temperatures.  
     
     
         4 . Use as claimed in  claim 3  wherein the halocarbon is tetrafluoroethane or heptafluoropropane.  
     
     
         5 . Use as claimed in any one of the preceding claims wherein the major proportion of the particles in sad medicament are between 0.5 and 10 μm.  
     
     
         6 . Use as claimed in any one of the preceding claims wherein the component capable of binding to lung tissue comprises phosphatidyl glycerol (PG).  
     
     
         7 . Use as claimed in any one of the preceding claims wherein the SAPL composition comprises a blend of dipalmitoyl phosphatidylcholine (DPPC) and PG.  
     
     
         8 . Use as claimed in  claim 7  wherein the PG is present in an amount sufficient to lower the temperature at which DPPC will spread spontaneously over a surface at normal mammalian blood temperature.  
     
     
         9 . Use as claimed in  claim 7  wherein the DPPC and PG are present in a weight ratio of from about 9:1 to 1:9.  
     
     
         10 . Use as claimed in  claim 7  wherein the DPPC and PG are present in a weight ratio of from about 6:4 to 8:2.  
     
     
         11 . Use as claimed in any one of the preceding claims wherein the medicament is prepared by forming a solution of the DPPC and the PG in a common solvent and recovering particles from the solution containing a mixture of DPPC and PG.  
     
     
         12 . Use as claimed in any one of the preceding claims wherein at least one component of the SAPL comprises a D or DL mixture.  
     
     
         13 . Use of an artificial lung surfactant in the preparation of a medicament for treatment of asthma by direct administration to the patient's airways or lungs of the medicament in finely-divided dry solid form, said medicament being essentially protein-free and comprising dipalmitoyl phosphatidylcholine (DPPC) in combination with phosphatidyl glycerol (PG).  
     
     
         14 . A dispersion device for administering a medicament useful in the treatment of asthma which comprises a sterile cartridge containing finely-divided particles of a blend of DPPC and PG, and means for introducing said particles into a gas stream as the patient inhales, said particles including a majority having particle sizes within the range of 0.5 to 2 μm.  
     
     
         15 . A dispersion device as claimed in  claim 14  wherein the DPPC and the PG are present in a weight ratio of from about 9:1 to 1:9.  
     
     
         16 . A device as claimed in  claim 14  or  15  which includes a source of propellant to form the gas stream.  
     
     
         17 . A dispenser for dispensing a powdered medicament which comprises a casing containing a valve-controlled canister of a halocarbon propellant and vial or capsule of a powdered SAPL, the canister being connected to the vial or capsule so that on operating the valve of the canister, gaseous propellant is forced into the vial or capsule and displaces the SAPL as a cloud into a mouthpiece.