Topical application of enoxaparin (ENX; low molecular weight heparin) prevents the occurrence of thrombosis at traumatic anastomosis site. Particulate carrier system like nanostructured lipid carriers (NLCs) could notably improve skin penetration of ENX. ENX-loaded NLCs were prepared by the solvent diffusion technique. The effect of formulation and process variables on the physicochemical properties of prepared NLCs was studied and characterized. In vitro skin permeation studies revealed better passage of enoxaparin by NLCs than of plain drug. The in vivo skin retention was monitored by fluorescence microscopy. The prepared NLCs when stored for 120 days were found to be more stable at 4 +/- 2 degrees C than room temperature. The overall results of the study demonstrated the importance of carrier composition on the physicochemical properties, morphology, skin irritation and consequently the effectiveness of particulate system as a vehicle for topical delivery of enoxaparin.