Paclitaxel and Erlotinib-co-loaded Solid Lipid Core Nanocapsules: Assessment of Physicochemical Characteristics and Cytotoxicity in Non-small Cell Lung Cancer. 
Lung cancer is the leading cause of cancer-related deaths.  The aim of this study was to design solid lipid core nanocapsules (SLCN) comprising a solid lipid core and a PEGylated polymeric corona for paclitaxel (PTX) and erlotinib (ERL) co-delivery to non-small cell lung cancer (NSCLC), and evaluate their physicochemical characteristics and in vitro activity in NCI-H23 cells.  PTX/ERL-SLCN were prepared by nanoprecipitation and sonication and physicochemically characterized by dynamic light scattering, transmission electron microscopy, differential scanning calorimetry, X-ray diffraction, and Fourier-transform infrared spectroscopy.  In vitro release profiles at pH 7.4 and pH 5.0 were studied and analyzed.  In vitro cytotoxicity and cellular uptake and apoptosis assays were performed in NCI-H23 cells.  PTX/ERL-SLCN exhibited appropriately-sized spherical particles with a high payload.  Both PTX and ERL showed pH-dependent and sustained release in vitro profiles.  PTX/ERL-SLCN demonstrated concentration- and time-dependent uptake by NCI-H23 cells and caused dose-dependent cytotoxicity in the cells, which was remarkably greater than that of not only the free individual drugs but also the free drug cocktail.  Moreover, well-defined early and late apoptosis were observed with clearly visible signs of apoptotic nuclei.  PTX/ERL-SLCN could be employed as an optimal approach for combination chemotherapy of NSCLC.