Method and apparatus for sealing medicinal capsules

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, and capsules formed by such method. The capsules produced by the process according to the invention are disposable and preferably contain a single dose of a pharmaceutical formulation in the form of a powder or liquid intended to be administered by 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.

1 . A capsule welded by a method of sealing parts of a plastic capsule to form 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 and wherein the capsule cap and capsule body are composed of a material which has a permeation coefficient for steam of less than 10 −13  kg/(m·s·Pa), 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 to form the weld seam thereon, the method resulting in a capsule having: in the overlapping region only, a weld seam formed by the energy beam bringing the capsule material to its melting point; and, in the rest of the capsule material not in the overlapping region, no effect from being brought to its melting point by the energy beam. 
     
     
         2 . The capsule of  claim 1 , wherein the capsule contains a medicament. 
     
     
         3 . The capsule to  claim 1 , wherein the capsule contains a medicament for inhalation. 
     
     
         4 . The capsule of  claim 1 , wherein the weld is formed around the entire circumference in the overlapping region. 
     
     
         5 . The capsule of  claim 1 , wherein the weld is formed only in a portion of the overlapping region. 
     
     
         6 . The capsule of  claim 1 , wherein the overlapping region where the weld is formed is less than 3 mm wide. 
     
     
         7 . The capsule of  claim 1 , wherein the overlapping region where the weld is formed is 0.5 mm to 1 mm wide. 
     
     
         8 . The capsule of  claim 1 , wherein the capsule cap and capsule body are composed of a material selected from the group consisting of: polyethylene (low density), polyethylene (high density), polystyrene, acrylonitrile-butadiene-styrene, polypropylene, polymethylmethacrylate, polyvinylchloride, and polyoxymethylene, each having a permeation coefficient for steam of less than 10 −13  kg/(m·s·Pa). 
     
     
         9 . The capsule of  claim 1 , wherein the capsule wall of the capsule has a thickness of 0.05 mm to 0.5 mm. 
     
     
         10 . The capsule of  claim 1 , wherein the length of the capsule is 8 mm to 30 mm. 
     
     
         11 . The capsule of  claim 1 , wherein the length of the capsule is 13 mm to 17 mm. 
     
     
         12 . The capsule of  claim 1 , wherein the diameter of the capsule is 4 mm to 7 mm. 
     
     
         13 . The capsule of  claim 1 , wherein the capsule is welded by laser light. 
     
     
         14 . The capsule of  claim 13 , wherein the capsule material contains a dye that absorbs the energy of the laser light. 
     
     
         15 . The capsule of  claim 1 , wherein the capsule cap and capsule body are composed of a material which has a permeation coefficient for steam of less than 1.3×10 −14  kg/(m·s·Pa). 
     
     
         16 . The capsule of  claim 1 , wherein the capsule cap and capsule body are composed of a material which has a permeation coefficient for steam between 10 −15  and 5×10 −16  kg/(m·s·Pa). 
     
     
         17 . The capsule of  claim 1 , wherein the capsule cap and capsule body are composed of high density polyethylene having a density between 950 kg/m 3  and 1000 kg/m 3 , having a permeation coefficient for steam of less than 10 −13  kg/(m·s·Pa). 
     
     
         18 . The capsule of  claim 1 , wherein the capsule contains a medicament for inhalation and the capsule wall of the capsule has a thickness of 0.05 mm to 0.5 mm.