Dissolution testing apparatus

• US 5,589,649 A
• Filed: 02/14/1995
• Issued: 12/31/1996
• Est. Priority Date: 02/25/1994
• Status: Expired due to Term

• Current Assignee: Distek, Inc.
• Original Assignee: Distek, Inc.
• Inventors: Gutwillig, Alan, Hladik, Peter, Brinker, Gerald
• Primary Examiner(s): Williams, Hezron E.
• Assistant Examiner(s): Brock, Michael J.
• Application Number:
  US08/389,063
• Time in Patent Office: 686 Days
• Field of Search: 73/53.01, 73/54.35, 73/54.38, 73/54.43, 73/866, 73/54.31, 422/68.1, 366/142, 366/143, 366/144, 366/197, 366/198, 366/249, 366/343, 219/385, 219/435, 219/521
• US Class Current: 73/866
• CPC Class Codes: B01L 7/00 Heating or cooling apparatus autoclaves B01J3/04; Heat insulating devices
• CPC Class Codes: G01N 13/00 Investigating surface or boundary effects, e.g. wetting power; Investigating diffusion effects; Analysing materials by determining surface, boundary, or diffusion effects scanning-probe techniques or apparatus G01Q
• CPC Class Codes: G01N 2013/006 Dissolution of tablets or the like
• CPC Class Codes: G01N 33/15 Medicinal preparations ; Physical properties thereof, e.g. dissolubility drug screening with animal cells G01N33/5008

Abstract

The dissolution testing apparatus has a plurality of stirring elements for stirring the test solutions within a plurality of test vessels with reflective surfaces. The temperatures of the test solutions are individually controlled by a temperature control system. The temperature control system includes a controller, a heating element for each test vessel to heat the corresponding test solution, and a temperature sensor for each test vessel to measure the temperature of the corresponding test solution. The heating elements are wrapped around the outside of the test vessels and held in place by spring-loaded heater jackets. Each stirring element has a hollow shaft, a detachable stirring attachment (e.g., blade or basket), a temperature sensor inside the hollow shaft, and a signal transfer device to transmit signals from the temperature sensor to the controller. The test vessels are supported and aligned with respect to the stirring elements with a holding plate having openings and corresponding alignment fixtures.

Claims

1. An apparatus for dissolution testing of a material in a test solution within a test vessel, comprising:

(a) a stirring element for stirring the test solution;

(b) a non-liquid-bath heating element placed around the outside of the test vessel for heating the test solution; and

(c) a controller for controlling the heating element to control the temperature of the test solution, wherein the stirring element comprises;

(1) a hollow shaft; and

(2) a temperature sensor located within the hollow shaft for generating signals representative of the temperature of the test solution when the hollow shaft is inserted into the test solution, wherein the controller controls the heating element in accordance with the signals from the temperature sensor.

2. The apparatus of claim 1, wherein the test vessel comprises a reflective coating applied to a surface of the test vessel.

3. The apparatus of claim 1, wherein the stirring element further comprises:

(3) a signal transfer device for transmitting the signals from the temperature sensor to the controller while the stirring element stirs the test solution.

4. The apparatus of claim 1, wherein the stirring element comprises:

(1) a shaft adapted to be removably coupled to a plurality of different stirring element attachments.

5. The apparatus of claim 4, wherein the plurality of different stirring element attachments comprises a blade attachment and a basket attachment.

6. The apparatus of claim 1, further comprising:

(d) a heater jacket surrounding the heating element for holding the heating element in place around the test vessel.

7. The apparatus of claim 6, wherein the heater jacket and heating element are configured to permit viewing of the stirring element through the front of the test vessel when the stirring element is inserted into the test vessel.

8. The apparatus of claim 6, wherein the heater jacket and heating element are configured to provide a gap between the outer surface of the heating element and the inner surface of the heater jacket.

9. The apparatus of claim 1, wherein the heating element comprises:

(1) a first heating area having a first power rating; and

(2) a second heating area having a second power rating different from the first power rating.

10. An apparatus for dissolution testing of a material in a test solution within a test vessel, comprising:

(a) a stirring element for stirring the test solution, wherein the stirring element comprises;

(1) a hollow stirring assembly; and

(2) a temperature sensor located within the hollow stirring assembly for generating signals representative of the temperature of the test solution, wherein the hollow stirring assembly comprises;

(1) a hollow shaft adapted to be removably coupled to a plurality of different stirring element attachments.

11. The apparatus of claim 10, wherein the test vessel comprises a reflective coating applied to a surface of the test vessel.

12. The apparatus of claim 10, wherein the stirring element further comprises:

(3) a signal transfer device for transmitting the signals from the temperature sensor while the stirring element stirs the test solution.

13. The apparatus of claim 10, wherein the plurality of different stirring element attachments comprises a blade attachment and a basket attachment.

14. The apparatus of claim 10, further comprising:

(b) a heating element placed around the outside of the test vessel for heating the test solution; and

(c) a controller for controlling the heating element to control the temperature of the test solution in accordance with the signals from the temperature sensor.

15. The apparatus of claim 14, further comprising:

(d) a heater jacket surrounding the heating element for holding the heating element in place around the test vessel.

16. The apparatus of claim 15, wherein the heater jacket and heating element are configured to permit viewing of the stirring element through the front of the test vessel when the stirring element is inserted into the test vessel.

17. The apparatus of claim 15, wherein the heater jacket and heating element are configured to provide a gap between the outer surface of the heating element and the inner surface of the heater jacket.

18. The apparatus of claim 14, wherein the heating element comprises:

(1) a first heating area having a first power rating; and

(2) a second heating area having a second power rating different from the first power rating.

19. An apparatus for dissolution testing of a material in a test solution, comprising:

(a) a test vessel for holding the test solution and the material, wherein the test vessel comprises a reflective coating applied to a surface of the test vessel; and

(b) a stirring element for stirring the test solution, wherein the stirring element comprises;

(1) a hollow shaft; and

(2) a temperature sensor located within the hollow shaft for generating signals representative of the temperature of the test solution.

20. The apparatus of claim 19, wherein the stirring element further comprises:

(3) a signal transfer device for transmitting the signals from the temperature sensor while the stirring element stirs the test solution.

21. The apparatus of claim 19, wherein the stirring element comprises:

(1) a shaft adapted to be removably coupled to a plurality of different stirring element attachments.

22. The apparatus of claim 21, wherein the plurality of different stirring element attachments comprises a blade attachment and a basket attachment.

23. The apparatus of claim 19, further comprising:

(c) a heating element placed around the outside of the test vessel for heating the test solution; and

(d) a controller for controlling the heating element to control the temperature of the test solution.

24. The apparatus of claim 23, further comprising:

(e) a heater jacket surrounding the heating element for holding the heating element in place around the test vessel.

25. The apparatus of claim 24, wherein the heater jacket and heating element are configured to permit viewing of the stirring element through the front of the test vessel when the stirring element is inserted into the test vessel.

26. The apparatus of claim 24, wherein the heater jacket and heating element are configured to provide a gap between the outer surface of the heating element and the inner surface of the heater jacket.

27. The apparatus of claim 23, wherein the heating element comprises:

(1) a first heating area having a first power rating; and

(2) a second heating area having a second power rating different from the first power rating.

28. An apparatus for dissolution testing of a material in a test solution within a test vessel, comprising:

(a) a stirring element for stirring the test solution, wherein the stirring element comprises;

(1) a shaft adapted to be removably coupled to a plurality of different stirring element attachments;

(b) a heating element placed around the outside of the test vessel for heating the test solution; and

(c) a controller for controlling the heating element to control the temperature of the test solution, wherein the heating element comprises;

(1) a first heating area having a first power rating; and

(2) a second heating area having a second power rating different from the first power rating.

29. The apparatus of claim 28, wherein the shaft is hollow and the stirring element further comprises a temperature sensor located within the hollow shaft for generating signals representative of the temperature of the test solution.

30. The apparatus of claim 29, wherein the stirring element further comprises a signal transfer device for transmitting the signals from the temperature sensor while the stirring element stirs the test solution.

31. The apparatus of claim 28, wherein the test vessel comprises a reflective coating applied to a surface of the test vessel.

32. The apparatus of claim 28, wherein the plurality of different stirring element attachments comprises a blade attachment and a basket attachment.

33. The apparatus of claim 28, further comprising:

(d) a heater jacket surrounding the heating element for holding the heating element in place around the test vessel.

34. The apparatus of claim 33, wherein the heater jacket and heating element are configured to permit viewing of the stirring element through the front of the test vessel when the stirring element is inserted into the test vessel.

35. The apparatus of claim 33, wherein the heater jacket and heating element are configured to provide a gap between the outer surface of the heating element and the inner surface of the heater jacket.

36. An apparatus for dissolution testing of a material in a test solution within a test vessel, comprising:

(a) a stirring element for stirring the test solution; and

(b) a holding plate having at least one opening for receiving and supporting the test vessel, the holding plate comprising a plurality of alignment fixtures for aligning the test vessel with respect to the stirring element.

37. The apparatus of claim 36, wherein each alignment fixture comprises two semi-rigid alignment arms adapted to provide compressive force to the test vessel.

38. The apparatus of claim 36, wherein the holding plate comprises three alignment fixtures for each opening.

39. The apparatus of claim 36, wherein the stirring element comprises:

(1) a shaft; and

(2) a stirring element attachment, adapted to be removably coupled to the shaft.

40. The apparatus of claim 39, wherein the shaft is hollow and the stirring element further comprises a temperature sensor located within the hollow shaft for generating signals representative of the temperature of the test solution.

41. The apparatus of claim 40, wherein the stirring element further comprises a signal transfer device for transmitting the signals from the temperature sensor while the stirring element stirs the test solution.

42. The apparatus of claim 36, wherein the test vessel comprises a reflective coating applied to a surface of the test vessel.

43. The apparatus of claim 36, further comprising:

(c) a heating element placed around the outside of the test vessel for heating the test solution; and

(d) a controller for controlling the heating element to control the temperature of the test solution.

44. The apparatus of claim 43, further comprising:

(e) a heater jacket surrounding the heating element for holding the heating element in place around the test vessel.

45. The apparatus of claim 44, wherein the heater jacket and heating element are configured to permit viewing of the stirring element through the front of the test vessel when the stirring element is inserted into the test vessel.

46. The apparatus of claim 44, wherein the heater jacket and heating element are configured to provide a gap between the outer surface of the heating element and the inner surface of the heater jacket.

47. The apparatus of claim 43, wherein the heating element comprises:

(1) a first heating area having a first power rating; and

(2) a second heating area having a second power rating different from the first power rating.

48. An apparatus for dissolution testing of a plurality of materials in a plurality of test solutions within a plurality of test vessels, comprising:

(a) a stirring element for each test vessel, for stirring the test solution, wherein each stirring element comprises;

(1) a hollow shaft;

(2) a stirring element attachment, adapted to be removably coupled to the hollow shaft, wherein the stirring element attachment is one of a blade attachment and a basket attachment;

(3) a temperature sensor located within the hollow shaft for generating signals representative of the temperature of the test solution when the hollow shaft is inserted into the test solution; and

(4) a signal transfer device for transmitting the signals from the temperature sensor while the stirring element stirs the test solution;

(c) a heating element for each test vessel, placed around the outside of the test vessel for heating the test solution, wherein the heating element comprises;

(1) a first heating area having a first power rating; and

(2) a second heating area having a second power rating different from the first power rating;

(d) a heater jacket for each test vessel, surrounding the heating element for holding the heating element in place around the test vessel, wherein the heater jacket and heating element are configured to permit viewing of the stirring element through the front of the test vessel when the stirring element is inserted into the test vessel and wherein the heater jacket and heating element are configured to provide a gap between the outer surface of the heating element and the inner surface of the heater jacket;

(e) a controller for controlling each heating element to control the temperature of each test solution in accordance with the signals from each temperature sensor.

49. An apparatus for dissolution testing of a material in a test solution within a test vessel, comprising:

(a) a stirring element for stirring the test solution;

(b) a heating element placed around the outside of the test vessel for heating the test solution; and

(c) a controller for controlling the heating element to control the temperature of the test solution, wherein the stirring element comprises;

(1) a hollow shaft; and

(2) a temperature sensor located within the hollow shaft for generating signals representative of the temperature of the test solution when the hollow shaft is inserted into the test solution, wherein the controller controls the heating element in accordance with the signals from the temperature sensor.

50. The apparatus of claim 49, wherein the stirring element further comprises:

(3) a signal transfer device for transmitting the signals from the temperature sensor to the controller while the stirring element stirs the test solution.

51. The apparatus of claim 49, further comprising:

(d) a heater jacket surrounding the heating element for holding the heating element in place around the test vessel.

52. The apparatus of claim 51, wherein the heater jacket and heating element are configured to permit viewing of the stirring element through the front of the test vessel when the stirring element is inserted into the test vessel.

53. The apparatus of claim 51, wherein the heater jacket and heating element are configured to provide a gap between the outer surface of the heating element and the inner surface of the heater jacket.

54. The apparatus of claim 49, wherein the heating element comprises:

(1) a first heating area having a first power rating; and

(2) a second heating area having a second power rating different from the first power rating.

55. An apparatus for dissolution testing of a material in a test solution within a test vessel, comprising:

(a) a stirring element for stirring the test solution;

(b) a heating element placed around the outside of the test vessel for heating the test solution; and

(c) a controller for controlling the heating element to control the temperature of the test solution, wherein the heating element comprises;

(1) a first heating area having a first power rating; and

(2) a second heating area having a second power rating different from the first power rating.

56. The apparatus of claim 55, wherein the test vessel comprises a reflective coating applied to a surface of the test vessel.

57. The apparatus of claim 55, wherein the stirring element comprises:

(1) a hollow shaft; and

(2) a temperature sensor located within the hollow shaft for generating signals representative of the temperature of the test solution when the hollow shaft is inserted into the test solution, wherein the controller controls the heating element in accordance with the signals from the temperature sensor.

58. The apparatus of claim 57, wherein the stirring element further comprises:

(3) a signal transfer device for transmitting the signals from the temperature sensor to the controller while the stirring element stirs the test solution.

59. The apparatus of claim 55, wherein the stirring element comprises:

(1) a shaft adapted to be removably coupled to a plurality of different stirring element attachments.

60. The apparatus of claim 59, wherein the plurality of different stirring element attachments comprises a blade attachment and a basket attachment.

61. The apparatus of claim 55, further comprising:

(d) a heater jacket surrounding the heating element for holding the heating element in place around the test vessel.

62. The apparatus of claim 61, wherein the heater jacket and heating element are configured to permit viewing of the stirring element through the front of the test vessel when the stirring element is inserted into the test vessel.

63. The apparatus of claim 61, wherein the heater jacket and heating element are configured to provide a gap between the outer surface of the heating element and the inner surface of the heater jacket.