Room temperature stable non-crystalline aspirin and method for the preparation thereof
The present invention provides stable non-crystalline aspirin that does not crystallize at room temperature during storage for prolonged periods of time and processes for obtaining the stable non-crystalline aspirin.
1. A process for the preparation of solid non-crystalline aspirin, comprising applying laser radiation from at least two different lasers to a solution of aspirin in a solvent, and evaporating the solvent, wherein the laser radiation has an effective average pulse length of no more than about 10 −9 seconds, and the laser radiation from each laser is of a different wavelength.
2. A stable, solid non-crystalline aspirin produced by the process of claim 1 , wherein there is substantially no crystallization in an entire sample of the stable, solid non-crystalline aspirin during storage for at least about 30 days at a temperature of from about 20° to about 30° C.
3. The stable, solid non-crystalline aspirin of claim 2 , wherein there is substantially no crystallization in the entire sample of the stable, solid non-crystalline aspirin during storage for at least about six months at a temperature of from about 20° to about 30° C.
4. The stable, solid non-crystalline aspirin of claim 2 , wherein the non-crystalline aspirin is microencapsulated.
5. The process of claim 1 , wherein at least one of the lasers emits visible light.
6. The process of claim 1 , wherein one laser emits radiation in the near UV to blue range, and one laser emits radiation in the red to near IR range.
7. The process of claim 1 , wherein one laser emits radiation having a wavelength in the range of from about 400 to about 470 nm, and one laser emits radiation having a wavelength in the range of from about 620 to about 680 nm.
8. The process of claim 1 , wherein the laser radiation is modified with a Strachan Device, the Strachan Device comprising a first diffraction grating, a second diffraction grating, and a refractive element positioned between the first and second diffraction gratings, wherein the Strachan Device cancels a portion of the laser radiation by destructive interference, and produces pulses of laser radiation by constructive interference.
9. The process of claim 8 , wherein the lasers are diode lasers.
10. The process of claim 1 , wherein the laser radiation has an effective average pulse length of no more than about 10 −12 seconds.
11. The process of claim 1 , wherein the laser radiation has an effective average pulse length of no more than about 10 −15 seconds.
12. The process of claim 1 , further comprising applying the laser pulses from at least two different lasers simultaneously.
13. The process of claim 1 , further comprising applying laser pulses from at least two different lasers in alternating sequences.
14. The process of claim 1 , wherein the solvent is an alcohol.
15. The process of claim 1 , wherein the solvent is an absolute alcohol.
16. The process of claim 1 , further comprising obtaining a solution of aspirin in a solvent;
placing the aspirin solution in a covered container;
applying the pulses of laser radiation pulses to the aspirin solution; and
evaporating at least a portion of the solvent while applying the laser pulses, thereby forming non-crystalline aspirin.
17. The process of claim 16 , further comprising heating the aspirin solution during the application of the laser pulses.
18. The process of claim 17 , further comprising heating the solution to a temperature of about 100° C.
19. The process of claim 16 , further comprising applying the laser radiation to the aspirin solution until the evaporation of the solvent is completed.
20. The process of claim 19 , further comprising cooling the aspirin to room temperature as the solvent evaporates.
21. The process of claim 16 , further comprising preventing evaporation of solvent for a period of time after the application of laser pulses is initiated, and then evaporating solvent while the application of laser pulses is continued.
22. The process of claim 21 , further comprising applying the laser radiation of the solution until the evaporation of the solvent is completed.
23. The process of claim 16 , further comprising applying the laser pulses from at least two different lasers simultaneously.
24. The process of claim 16 , further comprising applying laser pulses from at least two different lasers in alternating sequences.
25. The process of claim 16 , wherein the laser pulses are laser emissions modified with a Strachan Device, the Strachan Device comprising a first diffraction grating, a second diffraction grating, and a refractive element positioned between the first and second diffraction gratings, wherein the Strachan Device cancels a portion of the laser radiation by destructive interference, and produces pulses of laser radiation by constructive interference.
26. A pharmaceutical composition, comprising the stable, solid non-crystalline aspirin of claim 2 .
27. A stable, solid non-crystalline aspirin, having a PXRD pattern substantially as depicted in FIG. 2 , wherein there is substantially no crystallization in an entire sample of the stable, solid non-crystalline aspirin during storage for at least about 30 days at a temperature of from about 20° to about 30° C.
28. A process for preparing solid non-crystalline aspirin, the process comprising:
passing laser radiation through a Strachan Device, the Strachan Device comprising a first diffraction grating and a second diffraction grating and a refractive element positioned between the first and second diffraction gratings, wherein the Strachan Device cancels a portion of the laser radiation by destructive interference, and produces pulses of laser radiation by constructive interference;
applying the laser radiation passed through the Strachan Device to a solution of aspirin in a solvent; and
evaporating the solvent.
29. The process of claim 28 , wherein the pulses of laser radiation have an effective average pulse length of no more than about 10 −9 seconds.
30. A stable, solid non-crystalline aspirin produced by the process of claim 28 , wherein there is substantially no crystallization in an entire sample of the stable, solid non-crystalline aspirin during storage for at least about 30 days at a temperature of from about 20° to about 30° C.
31. The stable, solid non-crystalline aspirin of claim 30 , wherein there is substantially no crystallization in the entire sample of the stable, solid non-crystalline aspirin during storage for at least about six months at a temperature of from about 20° to about 30° C.
32. The stable, solid non-crystalline aspirin of claim 30 , wherein the non-crystalline aspirin is microencapsulated.
33. A pharmaceutical composition, comprising the stable, solid non-crystalline aspirin of claim 30 .