Abstract: Objective To design and prepare the nanostructured lipid carriers(NLC) and the lipid emulsion(LE) containing seal oil, and the anti-cancer drug docetaxel(DTX) as a model drug. Methods The DTX-NLC was obtained by high pressure homogenization. The release of DTX-NLC and DTX-LE in vitro were determined by dynamic dialysis method in PBS with 0.5% DMSO(pH7.4 and pH5.4), and in plasma. In vitro anti-tumor studies of DTX-NLC and DTX-LE were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay. While, in vivo anti-tumor activities of DTX-NLC and DTX-LE were determined in S180 bearing mice. Results The morphology of DTX-NLC was in spherical shape with approximately 200 nm in diameter and the zeta potential ranged from -30 to -50 mV, and the encapsulation efficiency is about 95%.The release percentage of DTX-NLC is(4.30±0.32)% and (8.12±0.32)% in PBS with 0.5% DMSO at pH 7.4 and pH 5.4, and the releasing of the DTX from the DTX-NLC was more sustained from the DTX-LE. The DTX-NLC and DTX-LE showed a good stability in plasma. MTT assays showed that the DTX-NLC, DTX-LE and DTX could inhibit the growth of the cells. Conclusion Vivo anti-tumor studies in S180 bearing mice showed thatthe NLC had better sustained-release effect than that of LE, and extend the dosing interval further, increase tolerated dose, reduce the side effects of drugs, and improve the compliance of medication safety and medication.

Key words: docetaxel, nanostructured lipid carrier, lipid emulsion, seal oil, anti-tumor