Investigations on 5-fluorouracil solid lipid nanoparticles (SLN) prepared by hot homogenization

The purpose of this study was to investigate the effect of different formulation factors on the properties of solid lipid nanoparticles (SLN) prepared by a hot homogenization method. Using the particle size, physical stability constant (K(e)) and zeta-potential as standards, the stability of SLNs was investigated as a function of phospholipid and poloxamer contents. It was demonstrated that the content of phospholipid had a significant influence on the zeta-potential, which increased considerably with increasing phospholipid content. However, the particle size increased remarkably when the phospholipid content was as high as 1.5% due to the increased viscosity. Poloxamer 188 exhibited no remarkable influence on particle size when the concentration was as low as 1.0%. The influence of the phospholipid and poloxamer content on the embedding ratios of drug substances was further studied using 5-fluorouracil (5-Fu) as a model drug. It was shown that the embedding ratio increased considerably with phospholipid content and independent of poloxamer content, implying that 5-Fu was incorporated into the phospholipid bilayer membrane.