Wurster accelerator with powder applicator
A Wurster processor and a powder feed system are coupled via an eductor so as to supply dry powder through the air diverter sleeve of the Wurster for discharging onto the circulating particles during operation of the Wurster. Agglomeration and aggregation of the particles is eliminated or minimized by isolating or separating the liquid spray by the spray gun from the dry powder.
1. A Wurster apparatus for coating particulates, including a gun assembly with a spray nozzle for spraying liquid onto the particulates, comprising:
a sleeve surrounding the gun assembly and the sleeve having a plurality of outlet ports; and
a source of dry powder connected to the sleeve so as to discharge the dry powder through the outlet ports in an outwardly radial direction to coat the particulates.
2. The Wurster apparatus of claim 1 wherein the dry powder source includes an eductor coupled to the sleeve to deliver dry powder from the source to the sleeve.
3. The Wurster apparatus of claim 1 wherein the sleeve has at least one inlet port for receiving the dry powder.
4. The Wurster apparatus of claim 1 further comprising an annular space between the spray nozzle and the sleeve, and the dry powder being supplied to the space for discharge through the ports.
5. The Wurster apparatus of claim 1 further comprising a pressurized air line between the dry powder source and the sleeve to carry the dry powder.
6. The Wurster apparatus of claim 1 wherein the dry powder is an excipient.
7. The Wurster apparatus of claim 1 wherein the dry powder is an active pharmaceutical ingredient.
8. The Wurster apparatus of claim 1 wherein the dry powder is a polymer.
9. The Wurster apparatus of claim 1 wherein the sleeve ports are below a tip of the spray nozzle.
10. The Wurster apparatus of claim 1 wherein the dry powder is applied to the particulate material without being suspended or solubilized in a liquid.
11. The Wurster apparatus of claim 1 wherein the dry powder is applied to the particulate material without agglomeration.
12. The Wurster apparatus of claim 1 wherein the outlet ports are spaced from the spray nozzle.
13. The Wurster apparatus of claim 1 wherein the outlet ports are directed at a 45° angle.
14. The Wurster apparatus of claim 1 wherein the outlet ports are radially spaced around the spray nozzle.
15. A Wurster apparatus for coating particulates, including a gun assembly with a spray nozzle for spraying liquid onto the particulates, comprising:
a dry powder source;
a pressurized air source; and
a conduit connected to the dry powder source and to the pressurized air source and having an outlet to deliver dry powder onto the particulates as the particulates are sprayed with liquid in the Wurster apparatus.
16. The Wurster apparatus of claim 15 wherein the conduit is a sleeve surrounding the spray nozzle to define an annular space through which the dry powder passes.
17. The Wurster apparatus of claim 15 wherein the outlet has a plurality of ports.
18. The Wurster apparatus of claim 17 wherein the ports are directed at a 45° angle.
19. The Wurster apparatus of claim 17 wherein the ports are radially spaced around the spray nozzle.
20. The Wurster apparatus of claim 15 wherein the outlet is below a tip of the spray nozzle.