SOLID LIPID NANOPARTICLES (SLN) - AN ALTERNATIVE COLLOIDAL CARRIER SYSTEM FOR CONTROLLED DRUG-DELIVERY

Solid lipid nanoparticles of a quality acceptable for i.v. administration were produced by high pressure homogenization. Dispersion at increased temperature (melted lipids) was performed to yield SLN loaded with lipophilic drugs (e.g. tetracaine base), incorporation of the hydrophilic drug iotrolan was achieved by homogenization of the drug-loaded lipid in its solid state. Recrystallization of the SLN after production was investigated using differential scanning calorimetry. Drug loading capacities of up to 9.8% of the lipid matrix were obtained, prolonged in vitro drug release was achieved over 5 weeks (prednisolone). SLN of optimized composition proved to be physically stable during sterilization (autoclaving) and on long-term as aqueous dispersion. Alternatively dry products were produced by lyophilization or spray-drying. SLN were surface-modified for drug targeting purposes using poloxamer 407 and poloxamine 908 polymers as surfactants in the production process. Production parameters were optimized to obtain nanoparticle sizes required for the envisaged targets, e.g. < 150 nm for endothelial cells.