Patent ID: 7547297

Claim:
A pharmaceutical piston stopper ( 2 ), comprising a base body ( 7 ′) made substantially from an elastomer and comprising a receiving cavity ( 6 ) for connecting with a displacement transferring element and a cap-shaped piston section ( 8 ) completely enclosed in an inert film ( 9 ′), the piston section in a working position facing contents of a syringe or carpule cylinder ( 1 ), an outer circumference of the piston section with its inert film ( 9 ′) abutting against the syringe or carpule cylinder ( 1 ), the piston stopper ( 2 ) having an uncoated sealing section ( 10 ) adjacent to the piston section ( 8 ), the uncoated sealing section and an entire edge region of the inert film ( 9 ′) flatly abutting in the working position against the syringe or carpule cylinder ( 1 ), the uncoated sealing section having at least two continuous sealing lips ( 11 ) on its outer circumference spaced-apart by a continuous recess ( 12 ), wherein the base body ( 7 ′) is made in one piece, with the receiving cavity ( 6 ) extending up into the piston section ( 8 ), and wherein the sealing section ( 10 ) has on its outer circumference an annular continuous sealing zone ( 13 ) directly adjacent to and directly adjoining the edge region of the inert film ( 9 ′) enveloping the piston section ( 8 ) and abutting against an inside wall of the syringe or carpule cylinder ( 1 ), said annular continuous sealing zone ( 13 ) projecting slightly radially beyond a surface of the entire edge region of the inert film ( 9 ′), so that in the working position the piston stopper ( 2 ) abuts with the sealing section ( 13 ) fully against the syringe or carpule cylinder ( 1 ).