Ferritin coupled solid lipid nanoparticles were investigated for tumour targeting. Solid lipid nanoparticles were prepared using HSPC, cholesterol, DSPE and triolien. The SLNs without ferritin which has similar lipid composition were used for comparison. SLNs preparations were characterized for shape, size and percentage entrapment. The average size of SLNs was found to be in the range 110-152 nm and maximum drug entrapment was found to be 34.6-39.1%. In vitro drug release from the formulations is obeying fickian release kinetics. Cellular uptake and IC(50) values of the formulation were determined in vitro in MDA-MB-468 breast cancer cells. In vitro cell binding of Fr-SLN exhibits 7.7-folds higher binding to MDA-MB-468 breast cancer cells in comparison to plain SLNs. Ex-vivo cytotoxicity assay on targeted nanoparticles gave IC(50) of 1.28 mu M and non-targeted nanoparticles gave IC(50) of 3.56 mu M. In therapeutic experiments, 5-FU, SLNs and Fr-SLNs were administered at the dose of 10 mg 5-FU/kg body weight to MDA-MB-468 tumour bearing Balb/c mice. Administration of Fr-SLNs formulation results in effective reduction in tumour growth as compared with free 5-FU and plain SLNs. The result demonstrates that this delivery system possessed an enhanced anti-tumour activity. The results warrant further evaluation of this delivery system.