Abstract: 
Targeted drug delivery through macrophages is an attractive and modified technique to improve therapeutic efficacy for various infection, viral and inflammatory disease and macrophages are the differentiating cell having precursor monocytes, promocytes and monoblast. In liver 80-90% of total body macrophages are present RES and kupffer cells are the site of macrophages in liver where they present and RES having the sugar receptor highly phagocytosed and important for determination of foreign particles, macrophages having self defense mechanism. Other techniques are receptor mediated targeting, negatively charged drug delivery Opsonization means the process by which a particular antigen are rendered more susceptible to phagocytosed. Opsonic material are used to enhance the extent of phagocytosis. Mannose binding lectins coat the microbes as opsonins and enhance neutrophil reactivity against them. RES, phagocytosis membrane having negative charge in it and so as its target, which make it difficult to come closer. So at the time of evaluation one must check the negative charged of target by zeta potential.

Keywords: Liver Macrophages, Kupffer Cells, RES, Opsonization.