Powder material for electrostatic application to a substrate and electrostatic application of the powder material to a substrate
Method of electrostatically applying powder material to a substrate, wherein the substrate is a pharmaceutical substrate and the powder material is pharmaceutically acceptable. At least some of the particles of the material comprise a core and a shell surrounding the core, and the material of the core and the shell have different physical and/or chemical properties.
1. A method of preparing a powder material and application to a pharmaceutical substrate or substrates, which method comprises
preparing a range of pharmaceutically acceptable powder materials, the particles of each of the powder materials comprising a core and a shell surrounding the core;
for each powder material, encapsulating a desired core material with a shell material, the core material comprising a component which can be varied selected from a binder polymer, one or more additives selected from a colorant, an opacifier, a pharmaceutically active material and a filler and optionally one or more other additives, the shell material having different physical and/or chemical properties from the core material and comprising a binder polymer and optionally one or more other additives, and wherein the same shell material is used for the range of powder materials produced; and
electrostatically applying one or more of said powder materials produced to a pharmaceutical substrate or substrates;
whereby a universal shell material is provided for use with various variable core compositions, permitting alterations to the components in the core without affecting electrostatic application of the powder material to a substrate.
2. A method according to claim 1 , wherein different pharmaceutically active materials and/or different amounts of pharmaceutically active material are included in the range of powders prepared.
3. A method according to claim 1 , wherein the core contains pharmaceutically active material.
4. A method according to claim 3 , wherein active material and filler are present in the core.
5. A method according to claim 3 , wherein the substrate contains a different pharmaceutically active material from the powder material.
6. A method according to claim 3 , wherein the substrate contains the same pharmaceutically active material as the powder material.
7. A method according to claim 3 , wherein the substrate contains no pharmaceutically active material.
8. A method according to claim 3 , wherein the substrate is a pharmaceutical solid dosage form.
9. A method according to claim 1 , wherein the shell comprises a binder polymer material having charge-control functionality and/or a separate charge-control agent.
10. A method according to claim 9 , wherein the shell comprises a binder polymer having charge-control functionality.
11. A method according to claim 1 , wherein the powder material contains one or more polymer binders selected from methacrylate polymers, polyvinylpyrrolidone, hydroxypropyl cellulose, hydroxypropyl methylcellulose phthalate and hydroxypropyl methylcellulose acetate succinate.
12. A method according to claim 1 , wherein the powder material contains a methacrylate.
13. A method according to claim 12 , wherein the powder material contains an ammonio-methacrylate copolymer.
14. A method according to claim 1 , wherein the powder material contains polyvinylpyrrolidone.
15. A method according to claim 1 , wherein the core contains a binder polymer having charge-control functionality and/or a separate charge-control agent.
16. A method according to claim 1 , wherein the shell has a thickness in the range of from 0.1 μm to 5 μm.
17. A method of preparing a powder material and application to a substrate which is a solid dosage form or to a plurality of such substrates, which method comprises:
preparing a range of powder materials, the particles of each of the powder materials comprising a core and a shell surrounding the core;
for each powder material, encapsulating a desired core material with a shell material, the core material comprising a component which can be varied selected from a binder polymer, one or more additives selected from a colorant, an opacifier, an active material for release in the environment in which the substrate is to be used and a filler and optionally one or more other additives, the shell material having different physical and/or chemical properties from the core material and comprising a binder polymer and optionally one or more other additives, and wherein the same shell material is used for the range of powder materials produced; and
electrostatically applying one or more of said powder materials produced to a solid dosage form or forms;
whereby a universal shell material is provided for use with various variable core compositions, permitting alterations to the components in the core without affecting electrostatic application of the powder material to a substrate.
18. A method according to claim 17 , wherein different active materials and/or different amounts of active material are included in the range of powders prepared.
19. A method according to claim 17 , wherein the shell comprises a binder polymer material having charge-control functionality and/or a separate charge-control agent.
20. A method according to claim 19 , wherein the shell comprises a binder polymer having charge-control functionality.
21. A method according to claim 17 , wherein the powder material contains one or more polymer binders selected from methacrylate polymers, polyvinylpyrrolidone, hydroxypropyl cellulose, hydroxypropyl methylcellulose phthalate and hydroxypropyl methylcellulose acetate succinate.