Dual vial adapter assemblages having a triple component construction as follows: a first vented female vial adapter for telescopic mounting on a drug vial, a second vented female vial adapter for telescopic mounting on a liquid vial and a tubular liquid transfer coupler for coupling the first vented female vial adapter and the second vented female vial adapter for establishing a dual sealed lumen arrangement therebetween. The dual sealed lumen arrangement includes a central sealed liquid lumen for gravitational flow of liquid contents from a liquid vial to a drug vial and a sealed air lumen radial outward from the central sealed liquid lumen for venting air displaced from the drug vial to the liquid vial for assisting the gravitational flow of liquid contents by creating a closed system between the liquid vial and the drug vial.