Particles

• US 7,727,555 B2
• Filed: 04/21/2005
• Issued: 06/01/2010
• Est. Priority Date: 03/02/2005
• Status: Expired due to Fees

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Inventors: Casey, Thomas V. II, Lanphere, Janel, DiCarlo, Paul, Buiser, Marcia, McKenna, Erin
• Primary Examiner(s): Seidleck; James
• Assistant Examiner(s): HAIDER, SAIRA BANO
• Application Number:
  US11/111,511
• Publication Number:
  US 20060199010A1
• Time in Patent Office: 1,867 Days
• Field of Search: 428402-40224, 4272133-213, 264 4- 47, 347/54, 347/75, 239/4, 239/102.1
• US Class Current: 424/489
• CPC Class Codes: A61K 41/00 Medicinal preparations obtained by treating materials with wave energy or particle radiation ; Therapies using these preparations
• CPC Class Codes: A61K 9/1694 resulting in granules or microspheres of the matrix type containing more than 5% of excipient
• CPC Class Codes: B01J 13/04 by physical processes, e.g. drying, spraying
• CPC Class Codes: B01J 2/02 by dividing the liquid material into drops, e.g. by spraying, and solidifying the drops
• CPC Class Codes: B01J 2/18 using a vibrating apparatus
• CPC Class Codes: Y10T 428/2984 Microcapsule with fluid core [includes liposome]

Abstract

Particles and related methods are disclosed. In some embodiments, a method of making particles can include forming a stream of a mixture including first and second materials, exposing the stream to a vibration, and treating the stream to form particles. The vibration can have, for example, a sinusoidal, triangular, and/or sawtooth waveform.

Claims

1. A method comprising:

forming a liquid stream of a mixture comprising a polymer and a gelling precursor;

exposing the liquid stream to a vibration generated by a dual-channel frequency generator, the vibration having a waveform selected from the group consisting of triangular waveforms, and sawtooth waveforms to form a stream of non-spherical drops comprising the polymer and the gelling precursor;

observing the stream of drops at a frequency generated by the dual-channel frequency generator, the frequency of observing being different from a frequency of the vibration, the difference between the frequency of observing and the frequency of the vibration being at most about 10 Hertz;

contacting the stream of drops with a gelling agent to form first particles comprising a gel; and

removing the gel from the first particles to provide second particles having pores.

2. The method of claim 1, wherein the waveform is a sawtooth waveform.

3. The method of claim 1, wherein the waveform is a triangular waveform.

4. The method of claim 1, wherein the liquid stream is laminar.

5. The method of claim 1, wherein the liquid stream is non-laminar.

6. The method of claim 1, wherein the second particles are conical.

7. The method of claim 1, wherein the second particles are diamond-shaped or spheroidal.

8. The method of claim 1, wherein the second particles are cylindrical.

9. The method of claim 1, wherein forming the liquid stream comprises forming the stream with a drop generator.

10. The method of claim 9, wherein the gelling agent is contained in a vessel, and a surface of the gelling agent is located at most about five inches below the drop generator.

11. The method of claim 1, wherein the method includes using a system comprising a temperature sensor or a pressure sensor.

12. A method, comprising:

forming a stream of non-spherical drops at a first frequency using a dual-channel frequency generator, the stream of drops comprising a mixture of a polymer and a gelling precursor;

observing the stream of drops at a second frequency generated by the dual-channel frequency generator;

treating the stream of drops with a gelling agent to form first particles, wherein the first particles comprise a gel; and

removing the gel from the first particles to provide second particles having pores.

13. The method of claim 12, wherein the second particles have an arithmetic mean diameter of at most about 3,000 microns.

14. The method of claim 12, wherein the dual-channel frequency generator has a first channel and a second channel, the first frequency is generated using the first channel, and the second frequency is generated using the second channel.

15. The method of claim 14, wherein the dual-channel frequency generator further comprises a third channel.

16. The method of claim 12, wherein observing the stream of drops at a second frequency comprises observing the stream of drops with a light.

17. The method of claim 16, wherein the light is a strobe light.

18. The method of claim 12, wherein observing the stream of drops at the second frequency comprises observing the stream of drops with a camera.

19. The method of claim 12, wherein observing the stream of drops comprises viewing the stream of drops using a combination of observation devices.

20. The method of claim 12, wherein the first frequency is at least about one Hertz.

21. The method of claim 12, wherein the first frequency is at most about 5,000 Hertz.

22. The method of claim 12, wherein the second frequency is at least about one Hertz.

23. The method of claim 12, wherein the second frequency is at most about 5,000 Hertz.

24. The method of claim 12, wherein the second frequency is about one Hertz.

25. The method of claim 12, wherein the method comprises forming the stream of drops at the first frequency and a third frequency.

26. The method of claim 12, wherein the method includes using a system comprising a temperature sensor or a pressure sensor.