Formation of an ester or {HEAD ~ an amide} of {TAIL ~ the disulfide compound} led to not only prolongation of the duration but also improvement of absorption characteristics as a result of increase of lipophilicity 
of
Formation of an ester or { HEAD ~ an amide } of { TAIL ~ the disulfide compound } led to not only prolongation of the duration but also improvement of absorption characteristics as a result of increase of lipophilicity
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL 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