Moreover, the choline carboxylates formed on the former reaction
could have innumerous applications due to the biocompatibility
and biodegradability of its components. Choline is fundamental
for the normal functioning of all cells and is considered an essential
micronutrient for humans [13]. Its combination with fatty acids
allows the production of surfactants completely made of materials
naturally occurring in the human body. As such these salts are
extremely appealing not only to the cosmetic industry but also
for drug delivery systems. This kind of surfactants can be easily
decomposed both physiologically and environmentally, with studies
showing that they are significantly less toxic than common surfactants
like sodium dodecylsulphate (SDS) or benzalkonium
chloride (BAC). Other advantage of the use of choline as counterion
is the substantial reduction of the Krafft point (which is a criterion
for the solubility of the surfactant in water) of fatty acids when
compared with their alkali counterparts. This means that choline
carboxylates are more soluble in water and are capable of forming
micelles at room temperature, in contrast to the restricted solubility
of homologous alkali soaps