Method and apparatus for producing uniform small portions of fine powders and articles thereof

Abstract

Uniform portions of fine powders are deposited on a substrate by electrostatic attraction in which the charge of the electric field and polarity of the charged particles are varied repeatedly to form a buildup of powder on the carrier surface.

1 - 37 . (canceled)  
     
     
         38 . A controlled quantity of powder carried on a substrate, comprising a plurality of layers of said powder in which adjacent layers carry opposite charges.  
     
     
         39 . A controlled quantity according to  claim 38 , wherein said powder comprises a pharmaceutical.  
     
     
         40 . A controlled quantity according to  claim 38 , wherein said substrate comprises a packaging medium.  
     
     
         41 . A controlled quantity according to  claim 40 , wherein said packaging medium comprises a blister, tablet, capsule or tublet.  
     
     
         42 . A controlled quantity according to  claim 41 , wherein said blister comprises a plastic or metal foil blister package.  
     
     
         43 . An apparatus for depositing onto a substrate controlled quantities of particulate material from a source of said material, said apparatus comprising a charge generator for applying a predetermined electrostatic charge to particles of said material upstream of a deposition zone in which said substrate is located, and a controller for repeatedly varying the polarity of charge being applied to said material and to said substrate.  
     
     
         44 . The apparatus according to  claim 43 , wherein the controller comprises a switch oscillator.  
     
     
         45 . The apparatus according to  claim 43 , wherein the controller includes a clock for varying the polarity of charge over time.  
     
     
         46 . The apparatus according to  claim 43 , wherein said controller is adapted to switch polarity applied to said powder and to said substrate in synchronization.  
     
     
         47 . The apparatus according to  claim 43 , and including sensors for measuring the mass flow of aerosol particles that pass into and out of the deposition zone.  
     
     
         48 - 71 . (canceled)  
     
     
         72 . A pharmaceutical unit dose medicament powder package wherein the powder is deposited using electrostatic means to form alternately charged layers of said powder.  
     
     
         73 . The package of  claim 72 , wherein said electrostatic means includes moving an aerosol through a deposition region, providing means for electrically charging said medicament powder, and providing an alternating electric field between said powder package and said aerosol.