Erodible device comprising surfactant for modifying {HEAD ~ the rate} of {TAIL ~ erosion} of the device 
Erodible device comprising surfactant for modifying { HEAD ~ the rate } of { TAIL ~ erosion } of the device
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH