Novo Nordisk A/S
DUAL CHAMBER DRUG RESERVOIR AND STOPPER THEREFOR

Abstract:

The present invention concerns an elastomeric stopper (18, 28, 38) for a drug reservoir, comprising: a stopper body (18.1, 28.1, 38.1) extending along a reference axis between a leading end surface (18.2, 28.2, 38.2) and a trailing end surface (18.3, 28.3, 38.3) and having a generally cylindrical sidewall with an outer body diameter, a circumferential convex rib (18.6, 28.6, 38.6) extending radially outwardly from the sidewall, a non-convex trim edge portion (18.7, 28.7, 38.7) at the trailing end surface (18.3, 28.3, 38.3), the non-convex trim edge portion (18.7, 28.7, 38.7) having an outer trim edge diameter which is greater than the outer body diameter and being axially spaced apart from the circumferential convex rib (18.6, 28.6, 38.6), providing an annular recess (18.9, 28.9, 38.9) therebetween. The elastomeric stopper (18, 28, 38) further comprises a channel structure (18.10, 28.10, 38.10) enabling fluid flow from the trailing end surface (18.3, 28.3, 38.3) to the annular recess (18.9, 28.9, 38.9) through the non-convex trim edge portion (18.7, 28.7, 38.7).