Abstract
Decomposition of nonionic surface active agents by pancreatic lipase was examined. Surfactants possessing ester bonding with fatty acid are easily decomposed by pancreatic lipase and the degree of such decomposition seems to be dependent on the kinds of fatty acid rather than the structure of surfactants when fairly soluble in water. Such lipophilic surfactants are liable to form an emulsion and are hardly decomposed and increase of the concentration of surfactants decreases the decomposition. Effect of solubilization of solutes was also examined. Solubilization of a non-polar solute, toluene, was found to decrease the decomposition of the surfactants with increasing amount of toluene. Solubilization of hexanol, possessing a polar group, was also found to decrease decomposition of Tween-type surfactants, such as polyoxyethylene sorbitan monolaurate and oleate, with increasing amount of hexanol. With Myrj-type, like polyoxyethylene oleate and stearate, the situation was somewhat different from the case of toluene and the decomposition of the surfactants increased with the increasing amount of hexanol up to a certain limit, after which decomposition of the surfactants decreased with increasing solubilization of hexanol. These experimental results indicated that there is a difference in the decomposition of surface active agents according to their structure.
