Method and apparatus for sealing medicinal capsules

• US 20030029558A1
• Filed: 07/23/2002
• Published: 02/13/2003
• Est. Priority Date: 07/28/2001
• Status: Active Grant

• Current Assignee: Boehringer Ingelheim Pharma GmbH & Company Kg (C.H. Boehringer Sohn AG & Co. KG)
• Original Assignee: Boehringer Ingelheim Pharmaceuticals Incorporated (C.H. Boehringer Sohn AG & Co. KG)
• Inventors: Hochrainer, Dieter, Wachtel, Herbert
• Granted Patent: US 6,949,154 B2
• Time in Patent Office: Days
• US Class Current: 156/272.8
• CPC Class Codes: A61J 3/072 Sealing capsules, e.g. rendering them tamper-proof
• CPC Class Codes: B29C 2035/0216 using Peltier-effect
• CPC Class Codes: B29C 2035/0822 using IR radiation
• CPC Class Codes: B29C 65/10 using hot gases (e.g. combustion gases) or flames coming in contact with at least one of the parts to be joined
• CPC Class Codes: B29C 65/103 direct heating both surfaces to be joined
• CPC Class Codes: B29C 65/1616 Near infrared radiation [NIR], e.g. by YAG lasers
• CPC Class Codes: B29C 65/1638 focusing the laser beam on the interface
• CPC Class Codes: B29C 65/1654 scanning at least one of the parts to be joined
• CPC Class Codes: B29C 65/1677 making use of an absorber or impact modifier
• CPC Class Codes: B29C 65/58 Snap connection
• CPC Class Codes: B29C 66/003 Protecting areas of the parts to be joined from overheating B29C66/348, B29C66/8744 take precedence
• CPC Class Codes: B29C 66/1122 Single lap to lap joints, i.e. overlap joints B29C66/45, B29C66/472, B29C66/52272 take precedence
• CPC Class Codes: B29C 66/1142 Single butt to butt joints
• CPC Class Codes: B29C 66/1222 comprising at least a lapped joint-segment
• CPC Class Codes: B29C 66/1224 comprising at least a butt joint-segment
• CPC Class Codes: B29C 66/12441 being a single wall
• CPC Class Codes: B29C 66/12821 comprising at least two overlap joint-segments
• CPC Class Codes: B29C 66/1284 comprising at least one butt joint-segment
• CPC Class Codes: B29C 66/1312 Single flange to flange joints, the parts to be joined being rigid the parts to be joined being flexible B29C66/133
• CPC Class Codes: B29C 66/54 Joining several hollow-preforms, e.g. half-shells, to form hollow articles, e.g. for making balls, containers; Joining several hollow-preforms, e.g. half-cylinders, to form tubular articles
• CPC Class Codes: B29C 66/5432 : joining hollow covers and hollow bottoms to open ends of container bodies
• CPC Class Codes: B29C 66/65 : with a relative motion between the article and the welding tool B29C65/10, B29C65/12 take precedence
• CPC Class Codes: B29C 66/652 : moving the welding tool around the fixed article
• CPC Class Codes: B29C 66/71 : characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29C 66/73115 : Melting point
• CPC Class Codes: B29C 66/73151 : Hardness
• CPC Class Codes: B29C 66/73321 : both parts to be joined being coloured
• CPC Class Codes: B29C 66/7352 : Thickness, e.g. very thin
• CPC Class Codes: B29C 66/73921 : characterised by the materials of both parts being thermoplastics
• CPC Class Codes: B29C 66/836 : Moving relative to and tangentially to the parts to be joined, e.g. transversely to the displacement of the parts to be joined, e.g. using a X-Y table B29C66/65 takes precedence
• CPC Class Codes: B29C 66/9121 : by measuring the temperature
• CPC Class Codes: B29C 66/9141 : by controlling or regulating the temperature
• CPC Class Codes: B29C 66/9161 : by controlling or regulating the heat or the thermal flux, i.e. the heat flux
• CPC Class Codes: B29C 66/919 : characterised by specific temperature, heat or thermal flux values or ranges specific electrical resistance values B29C66/81262
• CPC Class Codes: B29C 66/93451 : by controlling or regulating the rotational speed, i.e. the speed of revolution
• CPC Class Codes: B29C 66/939 : characterised by specific speed values or ranges
• CPC Class Codes: B29C 66/961 : involving a feedback loop mechanism, e.g. comparison with a desired value
• CPC Class Codes: B29K 2023/0633 : LDPE, i.e. low density polyethylene
• CPC Class Codes: B29K 2023/065 : HDPE, i.e. high density polyethylene
• CPC Class Codes: B29K 2023/12 : PP, i.e. polypropylene
• CPC Class Codes: B29K 2025/06 : PS, i.e. polystyrene
• CPC Class Codes: B29K 2027/06 : PVC, i.e. polyvinylchloride
• CPC Class Codes: B29K 2033/12 : Polymers of methacrylic acid esters, e.g. PMMA, i.e. polymethylmethacrylate
• CPC Class Codes: B29K 2055/02 : ABS polymers, i.e. acrylonitrile-butadiene-styrene polymers
• CPC Class Codes: B29K 2059/00 : Use of polyacetals , e.g. POM, i.e. polyoxymethylene or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2995/007 : Hardness
• CPC Class Codes: B29K 2995/0073 : smooth
• CPC Class Codes: B29L 2031/7174 : Capsules
• CPC Class Codes: Y10S 53/90 : Capsules
• CPC Class Codes: Y10T 156/10 : Methods of surface bonding and/or assembly therefor
• CPC Class Codes: Y10T 428/13 : Hollow or container type article [e.g., tube, vase, etc.]
• CPC Class Codes: Y10T 428/1352 : Polymer or resin containing [i.e., natural or synthetic]
• CPC Class Codes: Y10T 428/2982 : Particulate matter [e.g., sphere, flake, etc.]

Abstract

A method of sealing parts of a plastic capsule by forming a weld seam in an overlapping region of the parts of the capsule, wherein the capsule comprises a capsule cap having an open end and a capsule body having an open end, the method comprising:

(a) holding the capsule cap and the capsule body in a capsule holder comprising a first holding part and a second holding part which can be guided synchronously with one another, wherein the first holding part interlockingly surrounds the capsule cap and the second holding part interlockingly surrounds the capsule body;

(b) closing the capsule holder holding the capsule cap and the capsule body so that the open end of the capsule cap and the open end of the capsule body form a sealed cavity therebetween and form an overlapping region, wherein the overlapping region is not covered by the capsule holder, to obtain a closed capsule; and

(c) welding the closed capsule using an energy beam of hot gas or laser light on the overlapping region by forming the weld seam thereon. The capsules produced by the process according to the invention are disposable capsules and preferably contain a single dose of a pharmaceutical formulation in the form of a powder or liquid suitable for inhalation and are suitable, by their form and function, for use in powder inhalers or liquid nebulizers for producing aerosols. Aerosols thus produced can be inhaled, for example, in order to administer a pharmaceutical formulation to the lungs.

Claims

1. A method of sealing parts of a plastic capsule by forming a weld seam in an overlapping region of the parts of the capsule, wherein the capsule comprises a capsule cap having an open end and a capsule body having an open end, the method comprising:

(a) holding the capsule cap and the capsule body in a capsule holder comprising a first holding part and a second holding part which can be guided synchronously with one another, wherein the first holding part interlockingly surrounds the capsule cap and the second holding part interlockingly surrounds the capsule body;

(b) closing the capsule holder holding the capsule cap and the capsule body so that the open end of the capsule cap and the open end of the capsule body form a sealed cavity therebetween and form an overlapping region, wherein the overlapping region is not covered by the capsule holder, to obtain a closed capsule; and

(c) welding the closed capsule using an energy beam of hot gas or laser light on the overlapping region by forming the weld seam thereon.

2. The method of claim 1, wherein the capsule contains a medicament.

3. The method of claim 1, wherein the capsule contains a medicament for inhalation.

4. The method of claim 1, wherein the energy beam is guided at least once around the vertical axis of the overlapping region in a relative movement to the capsule.

5. The method of claim 1, wherein in the energy beam the capsule is guided by the first holding part and the second holding part synchronously moving without any torsional stress or shear stress so that the capsule material in the overlapping region begins to melt but is not destroyed.

6. The method of claim 1, wherein the entire overlapping region is welded.

7. The method of claim 1, wherein a portion of the overlapping region is welded.

8. The method of claim 1, wherein the capsule further comprises additional capsule parts which can be inserted telescopically into one another.

9. The method according to claim 1, wherein the capsule is held in the capsule holder by interlocking engagement so that the overlapping region is less than 3 mm wide.

10. The method according to claim 1, wherein the capsule is held in the capsule holder by interlocking engagement so that the overlapping region is 0.5 mm to 1 mm wide.

11. The method according to claim 1, wherein the capsule holder is aluminium, copper, stainless steel, or heat-resistant plastic.

12. The method according to claim 1, wherein the capsule is rotated during the welding step.

13. The method according to claim 1, wherein the angle of rotation and the energy beam are synchronized during the welding step.

14. The method according to claim 1, wherein the energy beam is guided around the overlapping region.

15. The method according to claim 1, wherein the capsule material and the processing temperature are selected from the following:

polyethylene (low density), 160°

C. to 260°

C.;

polyethylene (high density), 260°

C. to 300°

C.;

polystyrene, 170°

C. to 280°

C.;

acrylonitrile-butadiene-styrene, 210°

C. to 275°

C.;

polypropylene, 250°

C. to 270°

C.;

polymethylmethacrylate, 210°

C. to 240°

C.;

polyvinylchloride, 170°

C. to 210°

C.; and

polyoxymethylene, 200°

C. to 210°

C.

16. The method according to claim 1, wherein the capsule wall of the capsule has a thickness of 0.05 mm to 0.5 mm.

17. The method according to claim 1, wherein the capsule wall of the capsule has a thickness of 0.1 mm to 0.4 mm.

18. The method according to claim 1, wherein the capsule wall of the capsule has a thickness of 0.2 mm to 0.4 mm.

19. The method according to claim 1, wherein the length of the capsule is 8 mm to 30 mm.

20. The method according to claim 1, wherein the length of the capsule is 13 mm to 17 mm.

21. The method according to claim 1, wherein the length of the capsule is 15.5 mm to 16 mm.

22. The method according to claim 1, wherein the diameter of the capsule is 4 mm to 7 mm.

23. The method according to claim 1, wherein the diameter of the capsule is 5.3 mm to 6.3 mm.

24. The method according to claim 1, wherein the number of relative revolutions of the capsule in the energy beam is between 0.01 revolutions per second and 40 revolutions per second.

25. The method according to claim 1, wherein the number of relative revolutions of the capsule in the energy beam is between 0.01 revolutions per second and 20 revolutions per second.

26. The method according to claim 1, wherein the speed of advance of the capsule to the energy beam is 0.1 cm per second to 10 cm per second.

27. The method according to claim 1, wherein the speed of advance of the capsule to the energy beam is 1 cm per second to 5 cm per second.

28. The method according to claim 2, wherein the vertical axis of the weld seam to be produced is perpendicular to the energy beam and the fill level of the medicament in the capsule is below the weld seam to be produced.

29. The method according to claim 3, wherein the vertical axis of the weld seam to be produced is perpendicular to the energy beam and the fill level of the medicament in the capsule is below the weld seam to be produced.

30. The method according to claim 1, wherein the weld seam to be produced is located in the top third of the capsule.

31. The method according to claim 1, wherein the capsule holder includes a cooling device.

32. The method according to claim 31, wherein the cooling device is a water cooling device or a Peltier element.

33. The method according to claim 1, wherein the energy beam is a focussed or unfocussed laser beam.

34. The method according to claim 33, wherein the capsule is colored with a dye that absorbs the energy of the laser beam.

35. The method according to claim 33, wherein the capsule is colored in the overlapping region with a dye that absorbs the energy of the laser beam.

36. The method according to claim 33, wherein the capsule is colored at least in the region of the weld seam which is to be produced with a dye that absorbs the energy of the laser beam.

37. The method according to claim 34, wherein the dye is applied or is incorporated in the capsule material.

38. The method according to claim 35, wherein the dye is applied or is incorporated in the capsule material.

39. The method according to claim 36, wherein the dye is applied or is incorporated in the capsule material.

40. The method claim 34, wherein the dye used is a food-grade coloring.

41. The method claim 34, wherein the dye used is selected from red Fe_{2 O3}, red erythrosine, yellow beta-carotene, yellow FeO(OH), blue indigotine, green chlorophylline, beige caramel, and white titanium dioxide.

42. The method according to claim 33, wherein the laser beam is guided around the area of the capsule to be welded by means of a mirror.

43. The method according to claim 33, wherein a beam measuring device adjusts the speed of rotation between the capsule and the energy beam or adjusts the laser output.

44. The method according to claim 1, wherein the energy beam is a flow of hot gas with an area of impact on the area of the capsule to be welded of up to 3 mm.

45. The method according to claim 1, wherein the energy beam is a flow of hot gas with an area of impact on the area of the capsule to be welded of between 0.5 mm to 1 mm.

46. The method according to claim 45, wherein the relative movement between the energy beam and the part of the capsule to be welded is carried out at least twice before the weld seam is completely formed.

47. The method according to claim 1, wherein the capsule consists of the capsule body and capsule cap.

48. The method according to claim 1, wherein the capsule consists of the capsule body, capsule cap, and a cylindrical, internally hollow central region, the two open ends of which can be telescopically connected to the capsule body and the capsule cap.

49. A capsule welded by the method of claim 1.

50. A capsule holder comprising a first holding part and a second holding part, wherein the first holding part is adapted to interlockingly surround a capsule cap and the second holding part is adapted to interlockingly surround a capsule body.

51. The capsule holder according to claim 50, wherein the capsule holder includes a cooling device.

52. The capsule holder according to claim 51, wherein the cooling device is a water cooling device or a Peltier element.

53. An apparatus for sealing parts of a plastic capsule by forming a weld seam in an overlapping region of the parts of the capsule, wherein the capsule comprises a capsule cap having an open end and a capsule body having an open end, the apparatus comprising:

(a) holding means for holding a capsule holder in a welding region; and

(b) an energy source for proving an energy beam of hot gas or laser light on the overlapping region by forming the weld seam thereon,

wherein the capsule holder comprises a first holding part and a second holding part adapted for holding the capsule cap and the capsule body such that the first holding part interlockingly surrounds the capsule cap and the second holding part interlockingly surrounds the capsule body and, when the open end of the capsule cap and the open end of the capsule body brought together to form a sealed cavity therebetween, an overlapping region not covered by the capsule holder is formed.

54. The apparatus according to claim 53, further comprising a transporting means for transporting the capsule holder to the welding region.

55. The apparatus according to claim 54, wherein the transporting means is a conveyor belt.