In one embodiment, {HEAD ~ the non dissolvable region} or layer may be free of {TAIL ~ fatty acid} or fatty acid salt materials  
In one embodiment , { HEAD ~ the non dissolvable region } or layer may be free of { TAIL ~ fatty acid } or fatty acid salt materials
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH