Preparation of a dispersible PEGylate nanostructured lipid carriers (NLC) loaded with 10-hydroxycamptothecin by spray-drying.

Nanostructured lipid carriers (NLC) are based on mixture of solid lipids with spatially incompatible liquid lipids, which offer advantages of improving drug loading capacity and release properties. In the present study, hydroxycamptothecin (HCPT) loaded polyethylene glycol (PEG) modified NLC (PEG-NLC) was prepared by high pressure homogenize and spray drying method. PEG-NLC showed spherical particle with smooth surface in scanning electron microscopic (SEM) analysis. The crystallinity of lipid matrix within PEG-NLC was evaluated by powder X-ray diffraction and differential scanning calorimetry (DSC). The less ordered crystals or amorphous state of matrix were found in nanoparticles. A small, homogeneous particle size and high drug loading with fine entrapment efficiency of HCPT was obtained in PEG-NLC system. HCPT releasing from PEG-NLC showed a sustained release trend, and no significantly difference was found between two release curves of PEG-NLC before or after spray drying. After storage for 6 months, PEG-NLC powder after spray drying showed no significantly changes in particle size, drug loading and entrapment efficiency, crystal form and in vitro release. PEG modification statistically decreased the phagocytosis of NLC by RAW 264.7 cells, and spray drying process did not influence the cellular uptake of PEG-NLC. These results suggest that PEG-NLC prepared by spray drying is a stable and high-performance delivery system for HCPT.