Preparation and characterization of a nanostructured lipid carrier for a poorly soluble drug

The aim of this study was to prepare a stable nanostructured lipid carrier (NLC) with biocompatible lipids and surfactants (Pluronic F68 and Cremophor EL) by high-pressure homogenization (HPH). Surface tension measurements were used to choose the suitable ratio between Pluronic F68 and Cremophor EL. Hydrophobic anticancer drug docetaxel (DTX) was used as an active pharmaceutical ingredient (API). The mean particle size of docetaxel loaded nanostructured lipid carrier (DTX-NLC), as determined by dynamic light scattering (DLS), was between 120   nm and 250   nm during the storage period of 30 days, with the entrapment efficiency decreasing from (60.5   ±   5.0)% to (55.3   ±   4.5)%, while zeta potential was slightly changed from (−43.19   ±   3.6)   mV to (−40.12   ±   4.3)   mV. Transmission electron microscopy (TEM) showed that some of DTX-NLCs have elongated shape. Small angle neutron scattering (SANS) demonstrated that DTX-NLC in solution contained dense core with perfectly smooth surface, while blank NLC had dense core but rough surface. The blank NLC and DTX-NLC showed cubic crystalline structure according to small angle X-ray scattering (SAXS). Wide angle X-ray diffraction (XRD) showed that adding of DTX increased the crystallinity of the NLC. Cytotoxicity was studied by MTT assay against Hela cells. The data suggested that blank NLC was biocompatible with HeLa cells while the DTX-NLC was more cytotoxic than pure DTX at the same drug concentration. DTX-NLC could be taken up into the cells more than pure DTX, which could be attributed to the better solubility of DTX after loading into NLC.