Novel sulforaphane-enabled self-microemulsifying delivery systems (SFN-SMEDDS) of taxanes: Formulation development and in vitro cytotoxicity against breast cancer cells.

Paclitaxel (PTX) and docetaxel (DTX) are highly effective chemotherapeutic agents against breast cancer cells. Existing PTX and DTX formulations, however, contain excipients that result in a multitude of side-effects. The objective of the present study was to develop novel self-microemulsifying formulations of PTX and DTX with significantly lower excipient content by utilizing the high solubility of taxanes in sulforaphane (SFN). SFN-enabled microemulsions were developed by a screening process in which optical microscopy and absorbance data were used to monitor the physical stability of the dispersions. Optimized formulations contained vitamin E TPGS and transcutol to aid in taxane dissolution in water and the formation of transparent microemulsions (< 20 nm). SFN microemulsions were stable in different dilution media and storage temperatures and had no hemolytic effect on RBCs. When tested in vitro against MDA-MB-231 and MCF7 cancer cells by IncuCyte® live cell analysis and CellTiter-Blue® assay, taxanes/SFN microemulsions showed similar activity as the commercial taxanes injection solutions. SFN was only found to potentiate the activity of taxanes when used at high concentrations. This study highlighted the unique properties of SFN and its potential use in reformulating taxanes with high drug load and significantly lower excipient content than the commercial products.