Method for manufacturing seamless capsule

• US 6,719,933 B2
• Filed: 09/25/2002
• Issued: 04/13/2004
• Est. Priority Date: 12/20/1999
• Status: Active Grant

• Current Assignee: Chugai Seiyaku Kabushiki Kaisha (Roche Holding AG)
• Original Assignee: Chugai Seiyaku Kabushiki Kaisha (Roche Holding AG)
• Inventors: Nemoto, Kaoru, Matsuda, Isao, Nakamura, Takeshi, Nakajima, Hiroyuki
• Primary Examiner(s): Sergent, Rabon
• Assistant Examiner(s): TRAN, THAO T
• Application Number:
  US10/168,027
• Publication Number:
  US 20030090015A1
• Time in Patent Office: 566 Days
• Field of Search: 264/4, 264/9, 264/13, 264/14, 428/402.2, 424/16, 426/89
• US Class Current: 264/14
• CPC Class Codes: A61J 3/07 into the form of capsules or similar small containers for oral use
• CPC Class Codes: A61J 3/077 Manufacturing capsule shells
• CPC Class Codes: A61K 9/5089 Processes

Abstract

A method of making a spherical seamless capsule formed by encapsulating a filler material such as a medicine with a capsule shell material shell such as gelatin. A liquid capsule shell material is stored in a tank at a low temperature, and supplied to a concentric multiple nozzle while it temperature is raised to a predetermined temperature upon being gradually heated while being transferred to the concentric multiple nozzle. This prevents deterioration in the capsule shell material and excessive decrease in its viscosity. When the liquid filler material and the capsule shell material flow out of the concentric multiple nozzle, their flows are cut by imparting a vibration thereto, to form a droplet in which the filler material and the capsule shell material are disposed at the center and on the outside, respectively. Such droplets are dropped into a curing liquid while in a dispersed state to cure the surface of the capsule shell material.

Claims

1. A method of making a seamless capsule formed by encapsulating a filler material with a capsule shell material, said method comprising:

a step of preparing a concentric multiple nozzle having a center nozzle and an annular nozzle concentrically surrounding said center nozzle;

a step of storing a liquid filler material in a first tank;

a step of storing a liquid capsule shell material in a second tank at a predetermined first temperature by which said liquid capsule shell material maintains a substantially constant viscosity;

a step of preparing a curing bath for storing a curing liquid adapted to cure said liquid capsule shell material by coming into contact therewith;

a step of supplying said liquid filler material from said first tank to said center nozzle of said concentric multiple nozzle and supplying said liquid capsule shell material from said second tank to said annular nozzle of said concentric multiple nozzle;

a step of forming a droplet by cutting a flow of said liquid filler material caused to flow out of said center nozzle and a flow of said liquid capsule shell material caused to flow out of said annular nozzle and flow about said flow of said filler material; and

a step of bringing said capsule shell material of said droplet from said concentric multiple nozzle into contact with said curing liquid stored in said curing bath so as to cure said capsule shell material;

wherein, while transferring said liquid capsule shell material from said second tank to said annular nozzle of the temperature of the concentric multiple nozzle, the temperature of the capsule shell material is caused to rise with a substantially constant temperature gradient by heating during said transferring so as to attain a predetermined second temperature, higher than said first temperature, when entering said annular nozzle.

2. A method of making a seamless capsule according to claim 1, wherein a double tube comprising an inner tube and an outer tube surrounding said inner tube is prepared as a transfer tube for transferring said liquid capsule shell material between said second tank and said annular nozzle;

and

wherein said heating of said capsule shell material includes a step of circulating said liquid capsule shell material through said inner tube of said double tube while circulating a heating fluid for heating said capsule shell material in an annular space between said inner and outer tubes.

3. A method of making a seamless capsule according to claim 2, wherein a heater having a spiral tube communicating with said inner tube of said double tube is provided in the middle of said double tube;

and

wherein said heating of said capsule shell material includes a step of circulating said heating fluid for heating said capsule shell material about said spiral tube.

4. A method of making a seamless capsule according to one of claims 1 to 3, wherein a vibration is imparted to said liquid filler material and/or liquid capsule shell material supplied into said concentric multiple nozzle, so as to cut a flow of said liquid filler material and liquid capsule shell material flowing out of said concentric multiple nozzle, thereby forming said droplet.

5. A method of making a seamless capsule according to claim 4, wherein said vibration is imparted by using a movable wall as a wall portion defining a part of a flow path within said concentric multiple nozzle and vibrating said movable wall.

6. A method of making a seamless capsule according to claim 4, wherein said droplet from said concentric multiple nozzle is moderately dropped.

7. A method of making a seamless capsule according to one of claims 1 to 3, wherein droplets from said concentric multiple nozzle are dispersed into said curing liquid in said curing bath such that one droplet descending path and a next droplet descending path are horizontally distanced from each other.

8. A method of making a seamless capsule according to claim 7, wherein a vibration is imparted to said liquid filler material and/or liquid capsule shell material supplied into said concentric multiple nozzle, so as to cut a flow of said liquid filler material and liquid capsule shell material flowing out of said concentric multiple nozzle, thereby forming said droplet.

9. A method of making a seamless capsule according to claim 8, wherein said vibration is imparted by using a movable wall as a wall portion defining a part of a flow path within said concentric multiple nozzle and vibrating said movable wall.

10. A method of making a seamless capsule according to one of claims 1 to 3, wherein said droplet from said concentric multiple nozzle is moderately dropped.

11. A method of making a seamless capsule according to claim 1, wherein the transferring of said liquid capsule shell material from said second tank to said annular nozzle of said concentric multiple nozzle comprises moving said liquid capsule shell material through at least one passage associated with a heater.

12. A method of making a seamless capsule according to claim 11, wherein the moving of said liquid capsule shell material through at least one passage associated with a heater is performed without said liquid capsule material residing within said heater, thereby preventing said liquid capsule shell material from being heated for an undue amount of time.

13. A method of making a seamless capsule according to claim 1, wherein said heating of said capsule shell material is performed such that temperature of said capsule shell material rises with a substantially constant temperature gradient.

14. A method of making a seamless capsule according to claim 1, wherein, upon exiting said second tank, temperature of said liquid capsule shell material is raised only during transfer from said second tank to said concentric multiple nozzle.

15. A method of making a seamless capsule according to claim 1, wherein said transfer of said liquid capsule material from said second tank to said concentric multiple nozzle has a fixed time period whereby said liquid capsule material exhibits a constant physical property upon arrival at said concentric multiple nozzle.

16. A method of making a seamless capsule according to claim 1, wherein time of said heating is restricted so as to prevent occurrence of at least one of excessive decrease in viscosity of said liquid capsule material and deterioration of said liquid capsule material.