Therapeutic efficacy of lipid emulsions of docetaxel-linoleic acid conjugate in breast cancer.

Docetaxel (DTX) solution is among the most widely-used parenteral formulations used in advanced breast cancer therapy. However, severe side effects have been observed due to the use of ethanol and polysorbate 80. Herein, a novel DTX-based prodrug, docetaxel-linoleic acid conjugate (DTX-LA) was successfully synthesized. The high lipid solubility of DTX and DTX-LA resulted in a tendency for them to become entrapped in the oil core of the emulsions. As anticipated, nano-sized, sterically stabilized oil-in-water lipid emulsions (LMs) of DTX-LA LMs and DTX LMs were successfully constructed. Unlike DTX solution, LMs exhibited high colloidal stability and sustained-release behavior, having a narrow size distribution that was ∼220 nm in diameter. Compared with DTX LMs, DTX-LA LMs had a greater drug-loading capacity. Although the cytotoxicity of DTX-LA LMs was reduced in comparison with DTX solution, the pharmacokinetic study demonstrated increased bioavailability (p < 0.001) and half-life (p < 0.01). Finally, DTX-LA LMs displayed significant antitumor efficacy with reduced side effects in a 4T1 breast cancer xenograft model. Thus, the novel lipid emulsion-based docetaxel prodrug delivery system may be a promising strategy for improving intravenous administration for breast cancer treatment.