Mixing apparatus

• US 20020136089A1
• Filed: 04/12/2001
• Published: 09/26/2002
• Est. Priority Date: 02/17/2000
• Status: Active Grant

• Current Assignee: Astrazeneca AB (Astrazeneca PLC)
• Original Assignee: Astrazeneca AB (Astrazeneca PLC)
• Inventors: Folestad, Staffan, Johansson, Mats O.
• Granted Patent: US 6,595,678 B2
• Time in Patent Office: Days
• US Class Current: 366/287
• CPC Class Codes: B01F 27/953 using only helical stirrers
• CPC Class Codes: B01F 35/213 of the properties of the mixtures, e.g. temperature, density or colour

Abstract

A mixing apparatus for preparing from a plurality of materials, preferably powders, in particular components of a pharmaceutical composition, a mixture having a required homogeneity, comprising a non-rotating mixing vessel (7); at least one feeding mechanism for feeding said materials into said vessel (7); a stirring means (31) inside said vessel (7) for preparing said mixture; and at least one measuring device (23) for monitoring in-line at one or more locations in said vessel (7) the homogeneity of the mixture being prepared therein, wherein said at least one measuring device (23) comprises a unit for directing input radiation into said vessel (7), and at least one detector unit (45) for detecting output radiation formed by interaction of said input radiation with said materials in said vessel (7).

Claims

1. A mixing apparatus for preparing from a plurality of materials, preferably powders, in particular components of a pharmaceutical composition, a mixture having a required homogeneity, comprising:

a non-rotating mixing vessel (7),

at least one feeding mechanism (13, 14) for feeding said materials into said vessel (7),

a stirring means (31) inside said vessel (7) for preparing said mixture, and

at least one measuring device (23, 25, 27) for monitoring in-line at one or more locations in said vessel (7) the homogeneity of the mixture being prepared therein, wherein said at least one measuring device (23, 25, 27) comprises a unit (43) for directing input radiation into said vessel (7), and at least one detector unit (45) for detecting output radiation formed by interaction of said input radiation with said materials in said vessel (7).

2. An apparatus according to claim 1, wherein said at least one measuring device (23, 25, 27) is configured to measure in-line the homogeneity of the mixture being prepared in the vessel (7) at a plurality of locations therein.

3. An apparatus according to claim 1 or 2, comprising a plurality of measuring devices (23, 25, 27) for monitoring in-line at a plurality of locations in the vessel (7) the homogeneity of the mixture being prepared therein.

4. An apparatus according to any one of the preceding claims, wherein said at least one measuring device (23, 25, 27) cooperates with at least one stationary wall portion (7a) of said vessel (8).

5. An apparatus according to any one of the preceding claims, wherein said at least one measuring device (23, 25, 27) is attached to at least one stationary wall portion (7a) of said vessel (8).

6. An apparatus according to any one of the preceding claims, wherein said at least one measuring device (23, 25, 27) is a spectroscopic measuring device.

8. An apparatus according to claim 6 or 7, wherein the spectroscopic measuring device is an infra-red spectrophotometer.

9. An apparatus according to claim 6 or 7, wherein the spectroscopic measuring device is a near infra-red spectrophotometer.

10. An apparatus according to claim 6 or 7, wherein the spectroscopic measuring device is an x-ray spectrophotometer.

11. An apparatus according to claim 6 or 7, wherein the spectroscopic measuring device is a visible light spectrophotometer.

12. An apparatus according to claim 6 or 7, wherein the spectroscopic measuring device is a raman spectrophotometer.

13. An apparatus according to claim 6 or 7, wherein the spectroscopic measuring device is a microwave spectrophotometer.

14. An apparatus according to claim 6 or 7, wherein the spectroscopic measuring device is a nuclear magnetic resonance spectrophotometer.

15. An apparatus according to any of the preceding claims, wherein at least one of said at least one measuring device (23, 25, 27) is a polarimeter.

16. An apparatus according to any of the preceding claims, wherein the mixing vessel (7) is stationary.

17. An apparatus according to any of the preceding claims, wherein the mixing vessel (7) is part of a batch mixer.

18. An apparatus according to any of the preceding claims, wherein the mixing vessel (7) is a part of a convective mixer, preferably a Nauta mixer.

19. An apparatus according to any one of the preceding claims, wherein said units (43, 45) cooperate with at least one stationary wall portion (7a) of said vessel (8).

20. An apparatus according to any one of the preceding claims, wherein said vessel (7) essentially has the shape of an inverted cone with a vertical centre line (V), and wherein said stirring means (31) comprises a mixing screw having a longitudinal axis (L), a first drive means (33) being arranged to rotate said screw (31) around said longitudinal axis (L), and a second drive means (34) being arranged to bring about a precessing movement of said screw (31) around said vertical centre line (V).

21. An apparatus according to claim 20, wherein a first end (32) of said screw (31) is arranged on said vertical centre line (V), preferably at the bottom of said vessel (7).

22. An apparatus according to claim 19 or 20, further comprising at least one outlet port (11) at the bottom of said vessel (7).

23. An apparatus according to claim 22, further comprising a supply pipe (19) connected to said outlet port (11), and a flow control mechanism for causing the mixture to flow through the supply line (19).

24. An apparatus according to claim 23, wherein the flow control mechanism is a feed mechanism (21) for feeding said mixture through the supply line (19).

25. An apparatus according to claim 23, wherein the supply line (19) is configured such that the mixed material can flow by gravitational force therethrough and the flow control mechanism is a valve for selectively permitting the mixed material to flow through the supply line (19).

26. An apparatus according to claim 25, wherein the supply line (19) is substantially vertically directed.

27. An apparatus according to any one of the preceding claims, further comprising at least one inlet port (8, 9) in a top portion of said vessel (7).

28. An apparatus according to any one of the preceding claims, wherein said at least one feeding mechanism (13, 14) is arranged to selectively feed said materials into said vessel (7) through at least one inlet port (8, 9) of said vessel (7).

29. An apparatus according to claim 27 or 28, further comprising a plurality of supply vessels (3, 5) for containing separately the materials to be mixed in the mixing vessel (7), the supply vessels (3, 5) being connected to the at least one inlet port (8, 9) of the mixing vessel (7) by respective feed lines (12, 14) which each include a flow control mechanism operable to meter per unit time to the mixing vessel (7) amounts of the respective materials to be mixed.

7. An apparatus according to claim 7, wherein the spectroscopic measuring device is one of a reflectance, transflectance or transmission device.

30. A method of preparing from a plurality of materials, preferably powders, in particular components of a pharmaceutical composition, a mixture having a required homogeneity, comprising the steps of:

introducing said materials to be mixed into a non-rotating mixing vessel (7),

mixing the materials in the mixing vessel (7) by activating a stirring means (31) in said vessel (7), and

monitoring in-line at one or more locations in said vessel (7) the homogeneity of the mixture being prepared therein, by directing input radiation into said vessel (7) and by detecting output radiation formed by interaction of said input radiation with said materials in said vessel (7).

31. A method according to claim 30, wherein the homogeneity of the mixture being prepared in the vessel (7) is monitored at a plurality of locations therein.

32. An apparatus according to claim 30 or 31, wherein said mixing is effected by driving a mixing screw (31) in the vessel (7) to rotate about its longitudinal axis (L), and simultaneously driving said screw (31) to precess along a periphery wall portion of the vessel (7) around a vertical centre line (V) thereof.

33. An apparatus according to any one of claims 30-32, wherein the materials to be mixed are introduced as a batch into the mixing vessel (7).