Effect of adding an amphiphilic solubilization improver, sucrose distearate, on the solubilization capacity of nonionic microemulsions

We have studied the effect of adding sucrose distearate (2C(18)SE) on the s olubilization capacity of microemulsions formed in the water/C12EO6/n-decan e system. Upon addition of 2C(18)SE to the binary water/C12EO6 system, a la mellar liquid crystal region developed. This suggests that the rigidity of the surfactant layer is strengthened. The solubilization of water and n-dec ane in the bicontinuous microemulsions increases about three times upon rep lacing 10% C12EO6 With 2C(18)SE; besides, the HLB temperature is not greatl y affected by 2C(18)SE. On the other hand, sucrose monostearate (C18SE) doe s not have such a function. The effect of added 2C(18)SE On the solubilizat ion capacity of the discrete droplet-type o/w or w/o microemulsions was als o studied. The efficiency of the solubilization-improving effect is reduced when the system is far from the HLB temperature. (C) 2001 Academic Press.