Claims
- 1. A spray drying apparatus comprising
a primary drying chamber having an internal flow space terminating in a discharge outlet, and a secondary drying apparatus comprising tubing having an inlet in fluid communication with the discharge outlet of the primary drying chamber, wherein the ratio of the cross-sectional area of the primary drying chamber to the cross-sectional area of the tubing is at least 4:3, and wherein the ratio of the length of the tubing to the length of the primary drying chamber is at least 2:1.
- 2. The apparatus of claim 1 wherein the ratio of the length of the tubing to the length of the primary drying chamber is at least 3:1.
- 3. The apparatus of claim 1 wherein the ratio of the cross-sectional area of the primary drying chamber to the cross-sectional area of the tubing is between about 2:1 and 500:1.
- 4. The apparatus of claim 3 wherein the ratio of the cross-sectional area of the primary drying chamber to the cross-sectional area of the tubing is between about 4:1 and 100:1.
- 5. The apparatus of claim 4 wherein the ratio of the cross-sectional area of the primary drying chamber to the cross-sectional area of the tubing is about 16:1.
- 6. The apparatus of claim 1 wherein the tubing is in a coil.
- 7. The apparatus of claim 1 wherein the tubing is jacketed.
- 8. The apparatus of claim 1 wherein the tubing further comprises an outlet in fluid communication with a particle collection device.
- 9. The apparatus of claim 1 wherein the tubing comprises 50 RA or smoother stainless steel.
- 10. The apparatus of claim 1 adapted to be operable under sterile or aseptic conditions, thereby forming spray dried particles that are sterile.
- 11. A method of making particles comprising
(a) spraying an emulsion, solution or suspension which comprises a solvent and a bulk material through an atomizer, in a primary drying chamber having a discharge outlet and containing a drying gas, to form droplets of the solvent and bulk material dispersed in the drying gas; (b) evaporating a portion of the solvent into the drying gas to solidify the droplets and form particles; (c) flowing the particle and drying gas through a secondary drying apparatus comprising tubing having an inlet in fluid communication with the discharge outlet of the primary drying chamber, to evaporate a second portion of the solvent into the drying gas, wherein the ratio of the cross-sectional area of the primary drying chamber to the cross-sectional area of the tubing is at least 4:3, and wherein the ratio of the length of the tubing to the length of the primary drying chamber is at least 2:1.
- 12. The method of claim 11 wherein the ratio of the length of the tubing to the length of the primary drying chamber is at least 3:1.
- 13. The method of claim 11 wherein the ratio of the cross-sectional area of the primary drying chamber to the cross-sectional area of the tubing is between about 2:1 and 500:1.
- 14. The method of claim 13 wherein the ratio of the cross-sectional area of the primary drying chamber to the cross-sectional area of the tubing is between about 4:1 and 100:1.
- 15. The method of claim 14 wherein the ratio of the cross-sectional area of the primary drying chamber to the cross-sectional area of the tubing is about 16:1.
- 16. The method of claim 11 wherein the tubing is in a coil.
- 17. The method of claim 11 wherein the tubing is jacketed.
- 18. The method of claim 17 wherein the jacketing contains cooling water.
- 19. The method of claim 11 wherein the bulk material is a polymer and the particles are microparticles.
- 20. The method of claim 19 wherein the microparticles are between about 1 and 10 μm in diameter.
- 21. The method of claim 19 wherein the microparticles contain a therapeutic or diagnostic agent.
- 22. The method of claim 11 wherein the bulk material is a therapeutic or diagnostic agent.
- 23. The method of claim 11 wherein the solution or suspension further comprises a volatile salt that is volatilized in step (b), step (c), or a combination thereof.
- 24. The method of claim 11 wherein the drying gas entering the primary drying chamber in step (a) has an inlet temperature less than 100° C.
- 25. The method of claim 24 wherein the inlet temperature is less than 60° C.
- 26. The method of claim 25 wherein the inlet temperature is less than 40° C.
- 27. The method of claim 11 wherein the drying gas exiting the secondary drying apparatus has an outlet temperature less than 100° C.
- 28. The method of claim 27 wherein the outlet temperature is less than 60° C.
- 29. The method of claim 28 wherein the outlet temperature is less than 40° C.
- 30. The method of claim 29 wherein the outlet temperature is less than 25° C.
- 31. The particles made by the process of claim 11 comprising
(a) spraying an emulsion, solution or suspension which comprises a solvent and a bulk material through an atomizer, in a primary drying chamber having a discharge outlet and containing a drying gas, to form droplets of the solvent and bulk material dispersed in the drying gas; (b) evaporating a portion of the solvent into the drying gas to solidify the droplets and form particles; (c) flowing the particle and drying gas through a secondary drying apparatus comprising tubing having an inlet in fluid communication with the discharge outlet of the primary drying chamber, to evaporate a second portion of the solvent into the drying gas, wherein the ratio of the cross-sectional area of the primary drying chamber to the cross-sectional area of the tubing is at least 4:3, and wherein the ratio of the length of the tubing to the length of the primary drying chamber is at least 2:1.
- 32. The particles made by the process of claim 11 wherein the ratio of the length of the tubing to the length of the primary drying chamber is at least 3:1.
- 33. The particles made by the process of claim 11 wherein the ratio of the cross-sectional area of the primary drying chamber to the cross-sectional area of the tubing is between about 2:1 and 500:1.
- 34. The particles made by the process of claim 11 wherein the ratio of the cross-sectional area of the primary drying chamber to the cross-sectional area of the tubing is between about 4:1 and 100:1.
- 35. The particles made by the process of claim 11 wherein the ratio of the cross-sectional area of the primary drying chamber to the cross-sectional area of the tubing is about 16:1.
- 36. The particles made by the process of claim 11 wherein the tubing is in a coil.
- 37. The particles made by the process of claim 11 wherein the tubing is jacketed.
- 38. The particles made by the process of claim 11 wherein the jacketing contains cooling water.
- 39. The particles made by the process of claim 11 wherein the bulk material is a polymer and the particles are microparticles.
- 40. The particles made by the process of claim 11 wherein the microparticles are between about 1 and 10 μm in diameter.
- 41. The particles made by the process of claim 11 wherein the microparticles contain a therapeutic or diagnostic agent.
- 42. The particles made by the process of claim 11 wherein the bulk material is a therapeutic or diagnostic agent.
- 43. The particles made by the process of claim 11 wherein the solution or suspension further comprises a volatile salt that is volatilized in step (b), step (c), or a combination thereof.
- 44. The particles made by the process of claim 11 wherein the drying gas entering the primary drying chamber in step (a) has an inlet temperature less than 100° C.
- 45. The particles made by the process of claim 11 wherein the inlet temperature is less than 60° C.
- 46. The particles made by the process of claim 11 wherein the inlet temperature is less than 40° C.
- 47. The particles made by the process of claim 11 wherein the drying gas exiting the secondary drying apparatus has an outlet temperature less than 100° C.
- 48. The particles made by the process of claim 11 wherein the outlet temperature is less than 60° C.
- 49. The particles made by the process of claim 11 wherein the outlet temperature is less than 40° C.
- 50. The particles made by the process of claim 11 wherein the outlet temperature is less than 25° C.
Parent Case Info
[0001] This application is a continuation-in-part under 35 U.S.C. § 120 of U.S. Ser. No. 09/304,257 filed May 3, 1999.
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
09304257 |
May 1999 |
US |
Child |
09756950 |
Jan 2001 |
US |