Disclosed is a transfer device for use in reconstituting dry drugs and for diluting liquid drugs in drug containers. The transfer device includes a multi-port manifold and a connector suitable to be attached to a drug container, a first conduit to transfer a liquid entering an inlet port of the manifold through the connector and into the drug container, and a second conduit to transfer a gaseous fluid through the connector to an outlet port of the manifold. Also disclosed is a closed liquid transfer system which includes the transfer device, a tube connectable to the inlet port for transporting a liquid to the transfer device, a tube connectable to the outlet port for transporting the gaseous fluid away from the transfer device, and a gas collection container to collect the gaseous fluid in the gas transporting tube.