a pharmaceutical storage , mixing and dispensing vial is used to store first and second pharmaceuticals , mix the pharmaceuticals , and then provide access to the mixed pharmaceutical via a needle canula . the vial includes a container having an open end covered by a convex septum . a barrier within the container interior divides the interior into first and second interior regions housing the pharmaceuticals . the barrier has a plug sealing a hole the plug having an extension extending to the septum . the plug is driven from the opening by the plug extension when the septum is deflected into the container interior . the septum then naturally returns to its undeflected state to eliminate pressurization of the container interior .