Distribution and Transfer of Gatifloxacin Between Two Microemulsion Phases with Different Structures in SDS/n-C₅H₁₁OH/H₂O System

At a weight ratio of n-C₅H₁₁OH/H₂O=50/50, when the total content of sodium dodecyl sulfate (SDS) was less than 6.0%, the ternary mixture of SDS/n-C₅H₁₁OH/H₂O coexisted in two immiscible microemulsions. The distribution and transfer of gatifloxacin (GTFX) between the two phases were studied using UV-Vis and electrochemistry AC impedance spectra. The results show that GTFX transferred from the upper phase (W/O) to the lower phase (O/W or bicontinuous microemulsion), but a small amount of SDS transferred from the lower phase to the upper phase correspondingly with the increase of the total SDS content at a total GTFX concentration of 1.0×10⁻⁵ mol/L. The addition of GTFX did not change the structures of the two different phases fundamentally, but resulted in the transfer and redistribution of GTFX and SDS, so the electric properties of the system were changed correspondingly.