A valve (10) for permitting mixing of at least two components within a barrel (12) is provided including a stopper (20) configured for slidable liquid-tight engagement with an inner surface (13) of the barrel. The stopper is moveable between a first position and a second position and includes a proximal end (22), a distal end (24), and a channel (26) extending therebetween. The valve further includes a stationary body (30) comprising a base (32) and a stem (34), the stem being disposed within the channel of the stopper when the stopper is in the second position. When the stopper is in the first position, there is a liquid-tight seal in the channel, such that fluid flow through the channel is prevented. Movement of the stopper to the second position terminates the liquid-tight seal, thereby establishing fluid communication through the channel. A drug containing device and assembly for delivering a reconstituted drug are also provided herein.