Closed system stress resistant membrane

A membrane for sealing an open passageway in combination with a closed system transfer device, the closed system transfer device comprising a distal end and a proximal end connected by the passageway, a seat lip, and a membrane seat, the membrane comprising:

• a body having a proximal portion opposite a distal portion along a central axis, the proximal portion comprising a planar portion extending substantially perpendicular with respect to the central axis, the planar portion having an edge that transitions to a sidewall extending substantially parallel with the central axis, the sidewall being joined with a proximal surface of the distal portion;
• a skirt extending radially outward from the distal portion such that a lip is formed at a transition between the proximal portion and the distal portion, the lip comprising a planar surface continuously extending from the sidewall of the proximal portion to an outer edge of the skirt, the lip defining a proximal engagement surface engaged with the seat lip of the transfer device, the skirt having a distal engagement surface, wherein the distal engagement surface is oppositely disposed from the proximal engagement surface at a distalmost end of the skirt relative to a vertical axis extending through the body, the distalmost end of the skirt of the distal engagement surface engaged with the membrane seat of the closed system transfer device to retain the membrane in place to seal the open passageway and prevent axial movement of the membrane into the open passageway;
• at least one well recessed in the distal portion and extending from a distal end of the distal portion in a proximal direction, thereby forming a channel within the distal portion, the channel having an open first end, a closed second end, and a pair of sidewalls extending between the open first end and the closed second end, wherein the distalmost end of the skirt is defined by the channel and the outer edge of the skirt such that one of the pair of sidewalls comprises the skirt, and wherein the channel is configured to absorb deformation of a central portion of the body, wherein the second end of the channel is rounded and the pair of sidewalls are curved such that a width W between the sidewalls changes in a direction from the first end toward the second end or wherein the pair of sidewalls comprises a first sidewall and a second sidewall with the first sidewall extending in a direction substantially parallel to a direction of the central axis and the second sidewall extending at an angle relative to the first sidewall such that the second sidewall tapers away from the central axis in a distal-to-proximal direction;
• and
• at least one slit extending through at least a portion of the body in a direction of a plane aligned along or parallel to the central axis,
• wherein the seat lip is folded over the membrane in a radially inward direction, and wherein the membrane seat and seat lip comprises a single continuous member that prevents axial movement of the membrane within the closed system transfer device.

A membrane for sealing an open passageway in combination with a closed system transfer device, the closed system transfer device comprising a distal end and a proximal end connected by the passageway, and a membrane seat, the membrane comprising:

• a body having a proximal portion opposite a distal portion along a central axis, the proximal portion comprising a top portion extending substantially perpendicular with respect to the central axis, the top portion having an edge that transitions to a sidewall extending substantially parallel with the central axis, the sidewall being joined with a proximal surface of the distal portion;
• a skirt extending radially outward from the distal portion such that a lip is formed at a transition between the proximal portion and the distal portion, the lip comprising a planar surface continuously extending from the sidewall of the proximal portion to an outer edge of the skirt, the skirt defining an engagement surface at a distalmost end of the skirt, the engagement surface engaged with the membrane seat of the closed system transfer device to prevent axial movement of the membrane;
• at least one well recessed in the distal portion and extending from a distal end of the distal portion in a proximal direction, thereby forming a channel within the distal portion, the channel having an open first end, a closed second end, and a pair of sidewalls extending between the open first end and the closed second end, wherein the distalmost end of the skirt is defined by the channel and the outer edge of the skirt such that one of the pair of sidewalls comprises the skirt, said pair of sidewalls forming an open portion in the well, wherein the open portion extends from one of the pair of sidewalls to another one of the pair of sidewalls, the open portion configured to allow for radial expansion of a central portion defined by one of the pair of sidewalls without a corresponding expansion of the other one of the pair of sidewalls to minimize or eliminate coring during penetration of the membrane, wherein the second end of the channel is rounded and the pair of sidewalls are curved such that a width W between the sidewalls changes in a direction from the first end toward the second end or wherein the pair of sidewalls comprises a first sidewall and a second sidewall with the first sidewall extending in a direction substantially parallel to a direction of the central axis and the second sidewall extending at an angle relative to the first sidewall such that the second sidewall tapers away from the central axis in a distal-to-proximal direction;
• and
• at least one slit extending through at least a portion of the body in a direction of a plane aligned along or parallel to the central axis,
• wherein the membrane is configured to extend across and seal the open passageway within the closed system transfer device, and wherein the membrane seat retains the membrane from axially moving into the open passageway.