The present invention relates to a cationic lipid based aqueous formulation comprising cationic lipid, dexamethasone and a neutral co-lipid, wherein the said formulation is useful for selective targeting and delivering gene to glucocorticoid receptor expressing cancer cells. Glucorticoid receptors (GR) express in various normal and cancer cells. A lot of ligand activated physiological functions are known involving GR but its role in cancer progression (if any) is not clearly understood. Synthetic GR antagonist, dexamethasone (Dex) finds use as anti-inflammatory drug and is known to induce apoptosis in cancer cells. This Dex is included in a cationic lipid-based formulation as a co-lipid to deliver to and express genes specifically in cancer cells possibly through expressed GR. Gene delivery to cancer cells is independent of the gene construct, and tumor cell line. Normal transformed cells expressing GR but with no cancer lineage show much smaller level of transfection. The composition of the formulation is optimized. The formulation may have particular application to the enhanced delivery of anticancer genetic constructs to cancer, with the synergistic effect of Dex in inducing apoptosis as such.