Disclosed is a vented vial adapter, the adapter comprising a cannula having a medicament lumen and a vent lumen. The cannula having a 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 and a vent port in fluid communication with the vent lumen of the cannula, a first filter device disposed between the vent lumen of the cannula and the vent port and a second filter device disposed between the first filter device and the vent port.
