Dual approach utilizing self microemulsifying technique and novel P-gp inhibitor for effective delivery of taxanes

In the present work, concomitant use of self-microemulsifying drug delivery systems (SMEDDS) and a novel third-generation P-gp inhibitor, GF120918 (elacridar), for the effective transport of taxanes (paclitaxel and docetaxel) across an in vitro model of the intestinal epithelium and uptake into tumor cells were investigated. On the basis of solubility studies and ternary phase diagrams, different SMEDDS formulations of taxanes were prepared and characterized. In caco-2 cell permeation study, paclitaxel-loaded SMEDDS along with GF120918 showed a four-fold increase in apparent permeability, while docetaxel-loaded SMEDDS in combination with GF120918 showed a nine-fold increase in permeability, as compared to plain drug solution. Cell uptake studies on A549 cells were performed with microemulsions formed from both SMEDDS formulations loaded with rhodamine 123 dye and showed good uptake than plain dye solution. Confocal laser scanning microscopic images further confirmed the higher uptake of both SMEDDS formulations in the presence of GF120918.