Fluid from the environment is imbibed through a semipermeable plug into the water swellable agent chamber and the active agent formulation is released through {HEAD ~ a back diffusion} regulating {TAIL ~ outlet} 
regulating
Fluid from the environment is imbibed through a semipermeable plug into the water swellable agent chamber and the active agent formulation is released through { HEAD ~ a back diffusion } regulating { TAIL ~ outlet }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL