Patent ID: 7900659

Claim:
A pressure-equalizing vial access device for retaining aerosols when accessing a vial having a pierceable seal located over an opening of the vial, the vial access device comprising: a cannula having a medicament lumen and a vent lumen separate from the medicament lumen, the cannula having a relatively sharp tip to pierce the seal of the vial and a length selected so that the tip can be located within the vial; a body portion having: a medicament port in fluid communication with the medicament lumen of the cannula, the medicament port configured to receive a connector from a second container to allow liquid to be introduced into and removed from the vial; and a vent port in fluid communication with the vent lumen of the cannula, the vent port being separate from the medicament port and configured to allow passage of fluid to and from the vent lumen; and a rigid chamber located in fluid communication with the vent port and the vent lumen without being in fluid communication with the medicament port or medicament lumen, the rigid chamber having a pressure relief port open to atmosphere and an equalizing port connecting to the vent port and vent lumen, the rigid chamber having rigid walls and a fixed internal volume, the rigid chamber comprising: a filter disposed at the equalizing port of the rigid chamber so that any fluid passing between the rigid chamber and the vent port must pass through the filter; and a volume control device located within and entirely confined by the rigid chamber providing a sealed barrier between the equalizing port and the pressure relief port and freely movable between the equalizing port and the pressure relief port to vary the internal volume of the rigid chamber available to the equalizing port in response to pressure changes occurring in the vent lumen; whereby increases in pressure in the vial resulting from the introduction of liquid for reconstitution of vial contents are equalized by the volume control device moving away from the equalizing port to create a greater volume in the vent lumen/rigid chamber combination and decreases in pressure in the vial resulting from aspiration of reconstituted liquid from the vial contents are equalized by the volume control device moving toward the equalizing port to create a lesser volume in the vent lumen/rigid chamber combination.