West Pharmaceutical Services, Inc.

West Pharmceutical Services Deutschland Gmbh & Co. Kg

Jurgen Brinkhues

Xia Zhao

Heike Gruen

Jeffrey M Laubach

Joel Worman

Jason Mattia

A piston having a longitudinal axis and opposing proximal and distal axial ends is manufactured by a method including molding a partially formed piston body and then molding the piston. The partially formed piston body is molded by placing a first rubber sheet and an inert film between die plates of a first forming tool, vulcanizing the first rubber sheet and the inert film between the die plates of the first forming tool, and blanking out the partially formed piston body from the first rubber sheet and the inert film. The piston is then molded by placing the partially formed piston body into a second forming tool, placing a second rubber sheet into the second forming tool, vulcanizing the second rubber sheet and the partially formed piston body together, and blanking out the piston from the second rubber sheet at a trim edge spaced apart from the inert film.

Pharmaceutical syringe piston

A piston to be provided within an inner wall of a barrel of a pharmaceutical syringe for dispensing medicament retained in the barrel is described. The piston includes a body defining a central face, a cylindrical portion, and an annular curved portion between the cylindrical portion and the central face portion. The piston also includes an inert film enclosing the central face portion and at least a part of the annular curved portion. The cylindrical portion and the part of the annular curved portion are together configured to maintain a fluid-tight seal with the inner wall of the barrel. A pharmaceutical syringe is described for dispensing a medicament includes a barrel configured to retain the medicament and the piston.

A pharmaceutical syringe piston having a longitudinal axis includes a body having a central face portion with a first outer circumference and maximum first diameter. A cylindrical sealing portion proximate the central face portion has first and second axial ends and a wall extending therebetween. The wall has a second outer circumference and a second diameter essentially constant along the longitudinal axis between the first and second axial ends of the cylindrical sealing portion and is larger than the maximum first diameter. An annular curved portion has a maximum outer diameter less than the second diameter and connects the first axial end of the cylindrical sealing portion to the first outer circumference. An inert film encloses the central face portion and at least part of the annular curved portion and has an outer boundary between the first axial end of the cylindrical sealing portion and the first outer circumference.

A pharmaceutical syringe piston having a longitudinal axis includes a body having a central face portion with a first outer circumference and maximum first diameter. A cylindrical sealing portion proximate the central face portion has first and second axial ends and a wall extending therebetween. The wall has a second outer circumference and a second diameter essentially constant along the longitudinal axis between the first and second axial ends of the cylindrical sealing portion and is larger than the maximum first diameter. An annular curved portion has a maximum outer diameter less than the second diameter and connects the first axial end of the cylindrical sealing portion to the first outer circumference. An inert film encloses the central face portion and at least a part of the annular curved portion and has an outer boundary between the first axial end of the cylindrical sealing portion and the first outer circumference.

A piston stopper () made substantially of rubber has a piston section () enclosed in cap-like manner by an inert film () located adjacent to and facing the contents of a syringe or carpule cylinder (). A non-vulcanized rubber sheet () is inserted into a form tool, together with an inert film (). Under the effect of pressure and heat, an entire piston stopper contour is formed from the layered arrangement, extending to a flange () which protrudes laterally beyond the piston stopper () in the region of the separating plane of the form tool. A receiving cavity () for a piston rod is created in the piston section (). The wall area of the sealing section () surrounding the receiving cavity () is forced into the receiving cavity (). The piston stopper () is subsequently separated from the flange () in a blanking process, whereby a peripheral sealing area (), directly adjacent to the edge of the inert film () enclosing the piston section (), is formed in the sealing section ().

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Aachen, Germany

Jurgen Brinkhues