The location and conformation of fosinopril sodium (FS) in a lamellar
liquid crystal of water, sodium dodecyl sulfate, and decanol was studi
ed by low-angle X-ray diffraction. The result showed the FS molecule t
o be located within the amphiphilic part of the liquid crystalline str
ucture with the polar parts anchored at the water/polar part interface
. An area per molecule in the range of 95-100 Angstrom(2) showed not o
nly the polar groups but also the benzene ring to be located at this i
nterface.