ABSTRACT
Fat emulsions have been used in parenteral nutrition for patients who are unable to obtain adequate calories from food. Several commercial products, for example Intralipid, are marketed in many countries. Intravenously administered fat emulsions would be handled by the body as naturally-occurring fat-sorting particles. Once emulsions acquire apolipoproteins, they would undergo the metabolic and transport pathways of lipoproteins. Fat emulsions show diverse distribution patterns depending on their particle size and compositions. Fat emulsions would be handled by the body as fat-sorting lipoproteins or foreign particles. Oils and highly lipophilic compounds such as cholesteryl oleate form a core structure of a fat emulsion. In a fat emulsion-based drug delivery system, another issue should be important besides the disposition of fat emulsions: the drug retention in emulsion formulations. Fat emulsions will be a promising drug delivery system which can solubilize considerable amounts of lipophilic drugs, control the in vivo disposition of incorporated drugs, and deliver drugs selectively to a target site.
