Abstract: The cap of a unit dose tube and cap assembly has a dished shape outer wall defining a receptacle for liquid to be topically applied to the body. A groove is formed in the outer wall for snap-fitting engagement with a retention bead on the neck portion of the flexible walled tube for mounted the cap over a rupturable membrane which seals the discharge passage formed by the neck portion. The cap has a coaxial hollow spike and an annular groove in its outer wall likewise for snap-fitting engagement with the retention bead of the container neck portion in a position of use of the assembly. In such position the hollow spike ruptures the thin membrane wall and its passageway establishes communication between to the interior of the tube and the receptacle formed in the cap. An annular bead on the outer periphery of the receptacle aids in spreading the topical application.