Applicator systems

An applicator system, for use in delivering a flowable composition, comprising; (a) container including an inner collapsible layer distinct from an outer deformable layer, the inner collapsible layer defining a reservoir, and the outer deformable layer being separated from the inner collapsible layer by a buffer zone; (b) a dispenser including a first passageway distinct from a second passageway, the first passageway being in communication with the buffer zone and the second passageway being in communication with the reservoir; and (c) valve means operable to control entry of air into the buffer zone through the first passageway and exit of flowable composition from the reservoir through the second passageway; wherein the valve means is of unitary construction.