Patent ID: 8167863

Claim:
A vented vial adapter for retaining aerosols when accessing a vial having a pierceable seal located over an opening of the vial, the adapter comprising: a cannula having a medicament lumen and a vent lumen, the cannula having a relatively sharp tip to pierce the seal of the vial; a body portion having: a medicament port in fluid communication with the medicament lumen of the cannula, the medicament port configured 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 configured to allow passage of filtered air to and from an atmosphere outside the vial, thereby allowing air pressure in the vial to equalize with the outside atmosphere when liquid is introduced into and removed from the vial; a first filter device disposed between the vent lumen of the cannula and the vent port, the first filter device comprising pores having a diameter in the range of 0.2-3.0 microns and configured to allow passage of liquid dispersed in gas while blocking non-dispersed liquid; a second filter device disposed between the first filter device and the vent port, the second filter device configured to absorb liquid dispersed in gas; and a third filter device disposed between the second filter device and the vent port, the third filter device configured to inhibit the passage of bacteria, a pore size of the third filter device being smaller than 0.2 microns.