Powder coating composition for electrostatic coating of pharmaceutical substrates

Abstract

A powder coating material for use in the electrostatic powder coating of pharmaceutical tablet cores has the following properties: it is pharmaceutically acceptable, it is treatable to form a film coating on the surfaces of the tablet core and it includes composite particles comprising two or more components having different physical and/or chemical properties.

1 - 59 . (canceled)  
   
   
       60 . A method of electrostatically coating a substrate with a powder material, which comprises electrostatically applying said powder material to said substrate, the coated substrate being in the form of a tablet, and the powder material including composite particles formed from two or more different components and being in the form of discrete composite particles including each of the different components, at least 50% by weight of the particles of said powder material being in the form of said composite particles.  
   
   
       61 . A method according to  claim 60 , wherein substantially all the particles of said powder material are in the form of said composite particles.  
   
   
       62 . A method according to  claim 60 , wherein at least 30% by weight of the particles of said powder material have a particle size in the range of from 10 to 20 μm.  
   
   
       63 . A method according to  claim 60 , wherein at least 50% by volume of the particles of said powder material have a particle size of at least 5 μm.  
   
   
       64 . A method according to  claim 63 , wherein at least 75% by volume of the particles of said powder material have a particle size of at Least 5 μm.  
   
   
       65 . A method according to  claim 60 , wherein at least 30% by volume of the particles of said powder material have a particle size in the range of from 5 to 25 μm, at least 50% by volume of the particles have a particle size of at least 5 μm, and at least 90% by number of the particles have a particle size of less than 30 μm.  
   
   
       66 . A method of electrostatically coating a substrate with a powder material, which comprises electrostatically applying said powder material to said substrate, the coated substrate being in the form of a tablet, and the powder material including composite particles formed from two or more different components, substantially all the composite particles being in the form of discrete composite particles including each of the different components, wherein at least 30% by volume of the particles of said powder material have a particle size in the range of from 5 to 20 μm, at least 50% by volume of the particles have a particle size of at least 5 μm, and at least 90% by number of the particles have a particle size of less than 30 μm, and at least 50% by weight of the particles of said powder material are in the form of said composite particles.  
   
   
       67 . A method according to  claim 66 , wherein substantially all the particles of said powder material are in the form of said composite particles.  
   
   
       68 . A method according to  claim 66 , wherein at least 30% by weight of the particles of said powder material have a particle size in the range of from 10 to 20 μm.  
   
   
       69 . A method according to  claim 66 , wherein at least 75% by volume of the particles of said powder material have a particle size of at least 5 μm.  
   
   
       70 . A method according to  claim 60 , wherein said powder material includes a biologically active material included within said composite particles.  
   
   
       71 . A method according to  claim 70 , wherein at least 30% by volume of the particles of said powder material have a particle size in the range of from 5 to 20 μm.  
   
   
       72 . A method according to  claim 65 , wherein said powder material includes a biologically active material included within said composite particles.  
   
   
       73 . A method according to  claim 66 , wherein said powder material includes a biologically active material included within said composite particles.  
   
   
       74 . A method according to  claim 73 , wherein substantially all the particles of said powder material are in the form of said composite particles.  
   
   
       75 . A method according to  claim 70 , wherein the substrate contains no biologically active material.  
   
   
       76 . A method according to  claim 75 , wherein at least 30% by volume of the particles of said powder material have a particle size in the range of from 5 to 20 μm.  
   
   
       77 . A method according to  claim 73 , wherein the substrate contains no biologically active material.  
   
   
       78 . A method according to  claim 77 , wherein substantially all the particles of said powder material are in the form of said composite particles.  
   
   
       79 . A method of electrostatically coating a substrate with a powder material, which comprises electrostatically applying said powder material to said substrate, the coated substrate being in the form of a tablet, and the powder material being fusible to form a continuous film on the surface of said substrate at a temperature of less than 250° C. and being susceptible to movement under the action of electrostatic forces, and wherein said powder material includes composite particles formed from two or more different components, substantially all the composite particles being in the form of discrete composite particles including each of the different components, comprising a first component which is fusible to form a continuous film on the surface of the substrate at a temperature of less than 250° C. and which is substantially soluble in aqueous media, and a second component which is susceptible to movement under the action of electrostatic forces, at least 50% by weight of the particles of said powder material being in the form of said composite particles.  
   
   
       80 . A method according to  claim 79 , wherein substantially all the particles of said powder material are in the form of said composite particles.  
   
   
       81 . A method according to  claim 79 , wherein at least 30% by volume of the particles of said powder material have a particle size in the range of from 5 to 20 μm.  
   
   
       82 . A method according to  claim 79 , wherein at least 30% by volume of the particles of said powder material have a particle size in the range of from 5 to 25 μm, at least 50% by volume of the particles have a particle size of at least 5 μm, and at least 90% by number of the particles have a particle size of less than 30 μm.  
   
   
       83 . A method according to  claim 82 , wherein substantially all the particles of said powder material are in the form of said composite particles.  
   
   
       84 . A method according to  claim 79 , wherein said powder material includes a biologically active material included within said composite particles.  
   
   
       85 . A method according to  claim 84 , wherein at least 30% by volume of the particles of said powder material have a particle size in the range of from 5 to 20 μm.  
   
   
       86 . A method according to  claim 82 , wherein said powder material includes a biologically active material included within said composite particles.  
   
   
       87 . A method according to  claim 86 , wherein substantially all the particles of said powder material are in the form of said composite particles.  
   
   
       88 . A method according to  claim 84 , wherein the substrate contains no biologically active material.  
   
   
       89 . A method according to  claim 88 , wherein at least 30% by volume of the particles of said powder material have a particle size in the range of from 5 to 20 μm.  
   
   
       90 . A method according to  claim 86 , wherein the substrate contains no biologically active material.  
   
   
       91 . A method according to  claim 90 , wherein substantially all the particles of said powder material are in the form of said composite particles.  
   
   
       92 . A powder material suitable for use in the electrostatic coating of a pharmaceutical substrate, wherein the powder material is pharmaceutically acceptable, is fusible to form a continuous film on the surface of the substrate at a temperature of less than 250° C. and is susceptible to movement under the action of electrostatic forces, and wherein the powder material includes composite particles formed from two or more different components and being in the form of discrete composite particles including each of the different components, comprising a first component which is fusible to form a continuous film on the surface of the substrate at a temperature of less than 250° C. and which is substantially soluble in aqueous media, and a second component which is susceptible to movement under the action of electrostatic forces, at least 50% by weight of the particles of said powder material being in the form of the composite particles, and wherein at least 30% by volume of the particles have a particle size in the range of from 5 to 25 μm, at least 50% by volume of the particles have a particle size of at least 5 μm, and at least 90% by number of the particles have a particle size of less than 30 μm.  
   
   
       93 . A powder material according to  claim 92 , wherein substantially all the particles are in the form of said composite particles.  
   
   
       94 . A powder material according to  claim 92 , wherein at least 30% by volume of the particles have a particle size in the range of from 5 to 20 μm.  
   
   
       95 . A powder material according to  claim 94 , which includes a biologically active material included within said composite particles.  
   
   
       96 . A powder material according to  claim 95 , wherein at least 30% by volume of the particles have a particle size in the range of from 5 to 20 μm.