Stoppers used in pre-filled syringes

摘要

A stopper adapted for attachment with a plunger rod for use within a syringe barrel is disclosed. The stopper includes a main body defining an open rearward end and a closed front end. The open rearward end is adapted to receive a front forward end attachment portion of the plunger rod. The stopper also includes a core member integrally formed with the main body adjacent the closed front end. The core member includes a nose portion having a conical tip configured for entering an outlet opening of the syringe barrel. The closed front end of the stopper has a profile configured to cooperate with an internal surface of the syringe barrel wall to prevent reflux and reduce dead space within the barrel.

主权项

1. A stopper adapted for attachment with a plunger rod for use within a syringe barrel, said stopper comprising:
(a) a main body defining an open rearward end and a closed front end, said open rearward end adapted to receive a front forward end attachment portion of such plunger rod; (b) a core member integrally formed with said main body adjacent said closed front end, said core member including a nose portion and a stopper center post protruding from an interior of the core member toward the open rearward end, said stopper center post including a back core portion adapted for contact with said front forward end attachment portion of the plunger rod; (c) at least one rib extending radially outward around a perimeter of said main body for forming an active seal with such syringe barrel; and (d) an inward shoulder portion on an inner surface of said main body, said inward shoulder portion adapted for contact at a contact point with a taper on a forward end of the plunger rod, wherein contact of said inward shoulder portion with said taper causes the stopper to apply a radial force to said at least one rib and the syringe barrel upon the application of a forward force to the plunger rod, and wherein said inward shoulder portion includes a first cylindrical wall portion extending from the closed front end of said main body to the contact point, said first cylindrical wall portion having a substantially flat surface profile that is substantially uniform and non-tapered along its longitudinal length.