Chemically Talking, this molecule is "midway" among Sorbitan Oleate and Sorbitan Trioleate, indicating that it's also an attachment of sorbitan (a dehydrated sorbitol (sugar) molecule) with the unsaturated fatty acid Oleic Acid, but in the ratio of two:3 as a result the "Sesqui" component within the molecule's title. When Farmacy states "makeup me