Patent ID: 7972321

Claim:
A pressure regulating device for use with a sealed vial, the pressure regulating device comprising: a sheath being a part of a cap connector, the sheath configured to be positioned within the sealed vial when the pressure regulating device is used with the vial; a bag having an interior surface and an outer surface and adapted to be expanded or unfolded to compensate for changes in the volume of medicinal fluid that is within the sealed vial when the device is used with the sealed vial, the bag configured to move from a first orientation in which at least a portion of the bag is at least partially unexpanded or folded to a second orientation at least partially expanded or unfolded; and a lubricant at a surface of the bag to facilitate movement of the bag from the first orientation to the second orientation; wherein the bag comprises a layer that is substantially impermeable to a medicinal fluid disposed within the vial, thereby impeding the passage of said medicinal fluid between an outer surface and an inner surface of the bag; wherein the device regulates the pressure in the sealed vial such that, as said medicinal fluid is withdrawn from the sealed vial, the bag is configured to expand or unfold in order to substantially equilibrate pressure on opposite sides of the bag; and wherein the lubricant disposed on the surface of the bag reduces friction between one or more contacting surfaces of the bag while the bag is expanding or unfolding.