Fabrication of Oxaliplatin Microemulsion for Enhanced Cytotoxicity against Colon Cancer Cells

The aim of this study was to explore the potential of microemulsion (ME) to improve oxaliplatin efficacy against colon cancer cells. Oxaliplatin ME was prepared by water titration method using Miglyol 812 as oil phase, tween 80 and labrasol as surfactant and cosurfactant respectively. The constructed phase diagram showed the positioning of the ME towards surfactant/cosurfactant region. All the prepared ME formulae with negatively charged with particle size less than 100 nm. The conductivity results revealed that the ME could be water in oil or oil in water. Water amount could significantly affect conductivity, particle size and viscosity of the proposed ME. The incorporation of oxaliplatin in water in oil ME controlled the in vitro release for 24 h in contrast to only 2 h for oxaliplatin oil in water ME. The imparted lipophilicity produced by ME, especially water in oil ME, improved cytotoxicity against CT26 colon cancer cells by 1.7-2 fold. These results gave a rationale for further in vivo biological and toxicological studies