HK1088814A - Apparatus for and method of sealing capsules - Google Patents

Description

Device and method for sealing capsules

The present invention relates to a method and apparatus for sealing capsules and to capsules formed thereby.

The capsule sealed with the method and apparatus according to the invention is a hard-shelled telescopically connected capsule having coaxial partially overlapping body parts. The capsule may be made of gelatin or other material having pharmaceutically acceptable properties with respect to its chemical and physical properties.

The problem to be solved in relation to these capsules compared to other dosage forms is that the coaxial body parts must in fact seal well to avoid any leakage of the contents to the outside or contamination thereof. Furthermore, for safety reasons, any damage to the capsule contents or the capsule should be evident and visible from the outside. Any technique for sealing capsules must be suitable for large-scale mass production to reduce production time and cost and to reduce waste products due to product defects.

EP0116743a1, EP0116744a1, and EP0180543a1 disclose methods and devices for sealing such capsules having a coaxial enclosure of a rigid shell and body parts which overlap when telescopically connected. The adopted process comprises the following steps: i.e. batches of capsules either dipped in a mesh basket in any orientation or with its lid part standing into the sealing fluid to create a capillary orientation within the overlapping parts of the lid and body parts, or sprayed with the sealing fluid or its vapour onto the seams of the overlapping parts, removed from the capsule surface with a blower and heat applied to the capsules as the basket is conveyed through the dryer. This document discloses the use of a wide range of sealing fluids and specific temperatures and modes of application of thermal energy, the disclosure of which is incorporated herein by reference.

EP1072245a1 also discloses a method for sealing a telescopically connected capsule having coaxial body parts by removal of excess sealing liquid and application of thermal energy for drying purposes in the region of overlap at the connection of the cover and the body, followed by application of the sealing liquid. This document describes in particular the steps of applying a sealing liquid containing a solvent uniformly to the outer edge of the seam of the capsule to be sealed so as to form a liquid ring around the periphery of the capsule, removing excess sealing liquid from the outside of the capsule and drying the capsule by applying thermal energy from the outside while gently inverting and transporting the capsule on a spiral path. Nozzles are used to apply the sealing liquid separately. Excess solution is removed from around the capsule by vacuum suction or air jets. The disclosure of this document is also incorporated herein by reference.

Existing systems for sealing capsules are partially deficient in terms of sealing quality and controllability of process parameters affecting sealing quality.

The present invention is intended to provide an improved method and apparatus for sealing a telescopically joined capsule having coaxial partially overlapping body parts by subsequent application of a sealing fluid and improvement of the fluid injection phase in order to reach a maximum volume in the overlapping parts of the body parts while keeping no residual liquid on the capsule surface.

To this end, the present invention provides an improved method and apparatus for sealing a telescopically connected capsule having coaxial partially overlapping body parts as defined in the appended claims. Sealing clamps are used to efficiently seal hard capsules. The filled or empty capsules are oriented prior to the sealing operation. The sealing jaws hold each capsule in a precise and reproducible upright position. A known amount of sealing fluid is injected into a well-defined volume in the overlapping portion of the body parts. Excess sealing fluid is removed from the exterior of the capsule shell. In addition, excess sealing fluid is removed from the sealing clamp to prevent accumulation of sealing fluid. Finally the capsule is suitably loosened.

The application of the spray clamp instead of the sleeve and any other equipment enables the following zone restrictions: in this region, the sealing fluid is injected into the overlapping portions of the body parts. The design of the sealing clamp limits the location of the sealing fluid to the interior space of the clamp. The excess sealing fluid held in the clamp is recovered through the suction channel.

The use of a jetting fixture also forces the capsule to be cylindrical, which is advantageous when producing capsules from flexible polymer materials. Thus, the diameter of the capsule is uniform over 360 °. The penetration of the sealing liquid by capillary action over the entire capsule periphery is advantageous. A further advantage of using a sealing clamp is that a practically vertical positioning of the capsule with respect to the location of the sealing liquid injection hole is ensured.

The spray fixture may comprise different components. Each part will take part in a different step of the process. For example, the injection of sealing fluid may be performed in one component, while excess sealing fluid may be collected in a second component.

The number of main functional parts comprising the spray fixture may vary from one to six. The number of injection ports may vary from one to eight. The number of suction holes may vary from one to ten. The number of air passages may vary from one to six. The positions of those components may be spatially arranged to achieve the desired effect. One to three liquid recovery tanks may be added to the design of the fixture.

In a preferred embodiment, the sealing clamp comprises two parts. The two parts are connected together to open and close the sealing clamp.

The invention will now be described in more detail, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a first embodiment of a sealing clamp in an open position;

FIG. 2 shows a cross-section of the sealing clamp shown in FIG. 1 in a closed position;

FIG. 3 is a perspective view of a second embodiment of a sealing clamp in an open position;

FIG. 4 shows a cross-section of the sealing clamp of FIG. 3 in a closed position;

FIG. 5 is a perspective view of a third embodiment of a sealing clamp in an open position;

FIG. 6 shows a cross-section of the sealing clamp of FIG. 5 in a closed position;

FIG. 7 is a perspective view of a fourth embodiment of a sealing clamp in an open position;

FIG. 8 shows a cross-section of the sealing clamp of FIG. 7 in a closed position;

FIG. 9 is a perspective view of a fifth embodiment of a sealing clamp in an open position;

FIG. 10 shows a cross-section of the sealing clamp of FIG. 9 in a closed position;

FIG. 11 is a perspective view of a sixth embodiment of a sealing clamp in an open position;

FIG. 12 shows a cross-section of the sealing clamp of FIG. 11 in a closed position;

FIG. 13 is a perspective view of a seventh embodiment of a sealing clamp in an open position; and

fig. 14 shows a cross-section of the sealing clamp of fig. 13 in a closed position.

Fig. 1 and 2 show a first embodiment of a sealing clamp 1 comprising a first part 2 and a second part 3. In the closed sealing clamp, the edge of the cap of the capsule, not shown in the figures, is exactly between 0 and 2 mm above the injection opening 5. The sealing fluid is injected through an injection port 5 that is at 90 deg. to the parting line of the first component 2. Air or any other gas can flow through the air duct 6 at 45 deg. to the dividing line of the first part 2 and the two suction holes 7 at 90 deg. and 60 deg. to the dividing line of the second part 3. The injection port 5 and the air duct 6 are located between 0 and 2 mm below the edge of the enclosure, while the two suction holes 7 are located in the liquid recovery groove 8.

The difference between the first embodiment of the sealing jaw shown in fig. 1 and 2 and the other embodiments shown in fig. 3 to 14 is the number and positions of the injection ports 5, the air ducts 6, the suction holes 7 and the liquid recovery grooves 8. The first to fourth embodiments shown in fig. 1-8 are capable of sealing 20-50% of the maximum surface. With the sealing jig of the fifth embodiment, 80% of the surface area can be sealed. With the sealing jig of the sixth embodiment, a large sealing area of 90 to 100% can be obtained. With the sealing jaw of the seventh embodiment, it is possible to remove all excess sealing fluid from the capsule shell, preventing subsequent process defects.

The second embodiment of the sealing clamp 11 shown in fig. 3 and 4 comprises a first part 12 and a second part 13. In the closed sealing clamp, the edge of the cap of the capsule, not shown in the figures, is exactly between 0 and 2 mm above the injection port 15. The sealing fluid is injected through an injection port 15 that is at 90 to the parting line of the first component 12. Air or any other gas can flow through the chimney 16 at 75 deg. to the parting line of the first part 12 and the two suction holes 17 at 90 deg. and 60 deg. to the parting line of the second part 13. The injection port 15 is located between 0-2 mm below the edge of the cap of the capsule, while the air duct 16 and the two suction holes 17 are located in the liquid recovery groove 18.

A third embodiment of a sealing clamp 21 shown in fig. 5 and 6 comprises a first part 22 and a second part 23. In the closed sealing clamp, the edge of the cap of the capsule, not shown in the figures, is located at the bottom 29 of the liquid recovery tank 28. The sealing fluid is injected into the liquid recovery groove 28 through the injection port 25 which is at 90 ° to the boundary line of the first member 22. Air or any other gas can flow through the air passage 26 at 45 deg. to the parting line of the first part 22 and the two suction ports 27 at 90 deg. and 60 deg. to the parting line of the second part 23. The air duct 26 and the two suction holes 27 are located in the liquid recovery tank 28.

A fourth embodiment of a sealing clamp 31 shown in fig. 7 and 8 comprises a first part 32 and a second part 33. In the closed sealing clamp, the edge of the cap of the capsule, not shown in the figures, is located at the bottom 34 of the liquid recovery tank 38. The sealing fluid is injected into the liquid recovery groove 38 through the injection port 35 which is at 90 ° to the boundary line of the first member 32. Air or any other gas can flow through the air passage 36 at 45 deg. to the parting line of the first part 32 and the two suction holes 37 at 90 deg. and 60 deg. to the parting line of the second part 33. The air duct 36 and the two suction holes 37 are located in a liquid recovery tank 38. Additional features are an absorbent layer 39 and a vertical rubber coating 40 at the bottom of the sealing fixture 31.

A fifth embodiment of a sealing clamp 41 shown in fig. 9 and 10 comprises a first part 42 and a second part 43. In the closed sealing clamp, the edge of the cap of the capsule, not shown in the figures, is located at the bottom 50 of the liquid injection groove 49 of the sealing clamp 41. The sealing fluid is injected through two injection ports 45 at 60 deg. to the parting line of the first part 42 and at 60 deg. to the parting line of the second part 43. Two injection ports 45 enter the liquid injection groove 49. Air or any other gas may flow through two air passages 46 at 30 deg. to the dividing line of the first and second members 42, 43 and through four suction holes 47 at 90 deg. and 120 deg. to the dividing line of the first and second members 42, 43. The air duct 46 and the suction hole 47 are located in the liquid recovery tank 48.

A sixth embodiment of a sealing clamp 51 shown in fig. 11 and 12 comprises a first part 52 and a second part 53. In the closed sealing clamp, the edge of the cap of the capsule, not shown in the figures, is exactly between 0 and 2 mm above the injection port 55. The sealing fluid is injected through an injection port 55 at 60 ° to the parting line of the first component 52. Air or any other gas can flow through the chimney 56 at 90 deg. to the parting line of the first part 52 and the suction opening 57 at 120 deg. to the parting line of the second part 53. The air duct 56 and the suction hole 57 are located in the liquid recovery tank 58.

A seventh embodiment of a sealing clamp 61 shown in fig. 13 and 14 comprises a first part 62 and a second part 63. In the closed sealing clamp, the edge of the cap of the capsule, not shown in the figures, is located at the bottom 70 of the liquid injection groove 69 of the sealing clamp 61. The sealing fluid is injected through two injection ports 65 located at 135 deg. to the parting line of the first part 62 and at 135 deg. to the parting line of the second part 63. Two injection ports 65 enter the liquid injection groove 69. Air or any other gas may flow through two air ducts 66 at 150 ° to the dividing line of the first part 62 and the second part 63 and through four suction holes 67 at 30 ° and 60 ° to the dividing line of the first part 62 and the second part 63. The air duct 66 and the suction hole 67 are located in the liquid recovery groove 68.

Claims (8)

1. A method of sealing a hard shell capsule having coaxial body parts which overlap when telescopically connected, said method comprising the steps of:

maintaining the capsule in a precisely upright position,

a known amount of sealing fluid is injected into the overlapping portion of the body members to release the capsule.

2. The method of claim 1, wherein excess sealing fluid is removed from the exterior of the capsule shell.

3. Method according to claim 1 or 2, wherein excess sealing fluid is removed from a clamp holding the capsule in an upright position.

4. An apparatus for sealing hard shell capsules having coaxial body parts which overlap when telescopically connected, said apparatus comprising a sealing clamp (1, 11, 21, 31, 41, 51, 61) to hold said capsules in an upright position and means (5, 15, 25, 35, 45, 55, 65) to inject a sealing fluid into the overlapping parts of the cover and body parts.

5. The apparatus according to claim 4, characterized in that the means for injecting the sealing fluid is an injection port (5, 15, 25, 35, 45, 55, 65) in the sealing jaw (1, 11, 21, 31, 41, 51, 61).

6. The apparatus according to claim 4, characterized in that the sealing clamp has a fluid recovery tank (8, 18, 28, 38, 48, 58, 68).

7. The apparatus according to claim 4, characterized in that the sealing jaw has an air duct (6, 16, 26, 36, 46, 56, 66) and a suction hole (7, 17, 27, 37, 47, 57, 67).

8. The apparatus according to claim 4, characterized in that the sealing clamp has a liquid injection slot (49, 69).