Phase Behavior of Biocompatible Microemulsions Formed by Sucrose Stearate in the Presence of Sodium Deoxycholate

Biocompatible microemulsion has received increased interest among other self-assembly systems. On the basis of the phase behavior of sucrose stearate (S1570)/isopropyl alcohol/isoamyl acetate/water with α = 0.5 was investigated at 313 K, and found that emulsification occurs in this system. When the aqueous phase is changed to NaCl solution, the three-phase body appears after the addition of sodium deoxycholate (NaDC) to the S1570 system, And with a less amount of NaDC, the solubilization capacity of the mixed surfactant system is higher. On the other hand, the phase behavior of S1570/NaDC/isopropyl alcohol/isoamyl acetate/NaCl was studied at different temperatures and found that the addition of NaDC changes the temperature sensitivity of the microemulsion system formed using sucrose ester, and with increasing temperature the solubilization capacity of the system increases. The influence of the concentration of NaCl, chain lengh of the oil phase, and oil–water ratio on the phase behaviors was also discussed. Increasing the concentration of NaCl increases the solubilization capacity of the mixed system. With the chain length of oil phase increasing, the monomeric solubility in oil (<i>S</i>₁) and the interfacial concentration (<i>S</i>₁^S) of isopropyl alcohol are all increased, which in turn decreases the solubilization capacity of these systems