Medicinal aerosol formulations

Abstract

The present invention provides a process for making a stabilized medical aerosol suspension formulation for administration by a pressurized metered dose inhaler.

1 - 31 . (canceled) 
     
     
         32 . A method for preparing the medicinal aerosol suspension formulation for MDI administration, the formulation comprising:
 a) micronised formoterol fumarate or a pharmaceutically acceptable salt or derivative thereof in an amount of 0.003-0.04% by weight;   b) micronised fluticasone propionate or a pharmaceutically acceptable salt or derivative thereof in an amount of 0.01-0.6% by weight;   c) a sub-therapeutic quantity of a moisture-scavenger excipient comprising sodium cromolyn in an amount of 0.01-0.1% by weight; and   d) the propellant HFA 227,   the method comprising the step of incorporating sodium cromolyn into the formulation such that floccules of formoterol fumarate dihydrate, fluticasone propionate and sodium cromolyn are formed, wherein the floccules have a density substantially the same as that of the HFA propellant,   wherein the method provides a formulation having stability over a storage period from 3 to 18 months and the water content of the formulation after the storage period is in the range of 500 ppm to 800 ppm.   
     
     
         33 . The method of  claim 32 , wherein the amount of sodium cromolyn is from 0.01 to 0.1%, the amount of formoterol fumarate dihydrate is from 0.003 to 0.04%, and the amount of fluticasone propionate microparticles is from 0.01 to 0.6%. 
     
     
         34 . The method of  claim 32 , wherein the average density of the floccules is substantially the same as the density of the propellant ±0.2 g/cm 3 , ±0.1 g/cm 3 , or ±0.5 g/cm 3 . 
     
     
         35 . The method of  claim 32 , wherein the pharmaceutical suspension formulation additionally comprises a wetting agent, preferably a dehydrated alcohol, preferably ethanol.