Sumitomo Rubber Industries Limited

Naoyuki Ishida

Eiji Yao

Hiroaki Nakano

Shinya Iwano

Kazuhiro Fujisawa

Yuichiro Matsutani

The present invention provides a gasket for prefilled syringes having both airtightness and operability. The present invention relates to a gasket for prefilled syringes, the gasket including a plurality of circular ribs that are to be in sliding contact with the inner wall of a syringe, the gasket being laminated with an inert film, the plurality of circular ribs including a front circular rib having a front corner with a radius of curvature Rand a rear corner with a radius of curvature R, a ratio of the radius of curvature Rto the radius of curvature Rbeing more than 1.

Gasket for pre-filled syringe

Gasket for syringe

A gasket having a novel structure ensuring both the gas tightness and the low-friction slidability is provided. A sliding portion of the gasket () includes at least a first annular projection (A), an annular recess and a second annular projection (B) arranged in this order in a direction rearward from a distal portion of the gasket serving as a liquid contact portion. The first projection (A) is designed so that a first peak appears adjacent the distal portion of the gasket when the gasket is fitted in the syringe barrel () and a product &#x3b1; of a contact pressure Pand a width Dof the first peak is 0.4&#x2266;&#x3b1;&#x2266;1.0 as determined by an FEM analysis.

Gasket to be used for medical syringe, and medical syringe

Growing community of inventors

Kobe, Japan

Naoyuki Ishida