is completely enclosed in the plastic material of the outer layer 1 the two plastic materials are injected in co axially through the same injection nozzle 3 the material of the outer layer 1 surrounding that of the second layer 2 during the second injection phase in which the two plastic materials are simultaneously injected in the hollow cross section 10 of the mold is filled such that the layer structure shown in fig2 results for the plastic body 4 at the end of the injection process the supply of the plastic material for the second layer 2 can be discontinued and once again only the material of the outer layer 1 injected in in order to also obtain a closed outer layer 1 in the region of the injection nozzle 3 fig2 shows the plastic body 4 after being removed from the injection mold of fig1 the plastic body 4 forms a simple cylindrical crucible open to one side for storing liquids or other material clearly shapes other than cylindrical may be produced by suitable molds and or molding processes fig3 shows a container 5 u2014 in this exemplary embodiment an ampoule u2014 for storing a liquid active agent solution for example insulin a growth hormone or the like the ampoule 5 comprises a core layer 2 enclosed in an outer layer 1 as in the container 4 of fig1 and 2 a three layered structure results as viewed from the inside out with the same inner and outer thin outer layer 1.