Pellets as carriers of solid lipid nanoparticles (SLN) for oral administration of drugs

In the present study, a method for the preparation of pellets with solid li pid nanoparticles is reported. Solid lipid nanoparticles (SLN) were prepare d by high pressure homogenization of a coarse emulsion. The nanoparticles w ere characterized with regard to particle size and size distribution (laser diffraction and photon correlation spectroscopy) and zeta potential (laser Doppler anemometry). Lactose, microcrystalline cellulose and water were us ed in the production of pellets. The aqueous phase of the dispersion of nan oparticles was used as the aqueous phase in the processing of the pellets b y extrusion and spheronisation. Pellets were characterized for size and siz e distribution (sieving) and surface defects (visual inspection). An USP XX III apparatus was used to determine the release of the nanoparticles from t he pellets and the concentration of the nanoparticles was assessed by laser diffractometry and the obscuration obtained compared to the obscuration of the standard (diluted solid dispersion). The batches of solid lipid nanopa rticles produced were monodisperse, with a narrow size distribution and a z eta potential of -20 mV. The solid lipid nanoparticles were stable for at l east 2 months, at 4 degrees C. More than 90% of the spherical pellets produ ced were in the range between 1.00 and 1.25 mm in diameter and presented a smooth surface. The pellets, once in contact with an aqueous environment di sintegrated within 5 min, releasing the nanoparticles. The properties of th e nanoparticles were not affected by incorporation in pellets and their rel ease from the pellets was almost complete (between 80.5 and 96.0%).