{HEAD ~ The open end} of {TAIL ~ the water swellable agent chamber} contains a semipermeable membrane and the open end of the active agent chamber contains a back diffusion regulating outlet 
of
{ HEAD ~ The open end } of { TAIL ~ the water swellable agent chamber } contains a semipermeable membrane and the open end of the active agent chamber contains a back diffusion regulating outlet
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH