In other words, while the substantially non dissolvable region or layer may be somewhat soluble in water, the dissolvable region or {HEAD ~ layer} will have {TAIL ~ a substantially greater solubility} in water so as to dissolve, leaving the non dissolvable region or layer substantially intact at the end of the useful life of the shaped composition 
have
In other words , while the substantially non dissolvable region or layer may be somewhat soluble in water , the dissolvable region or { HEAD ~ layer } will have { TAIL ~ a substantially greater solubility } in water so as to dissolve , leaving the non dissolvable region or layer substantially intact at the end of the useful life of the shaped composition
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 OTH REL 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 OTH OTH OTH OTH OTH OTH OTH OTH