Submicron emulsions as colloidal drug carriers for intravenous administration: comprehensive physicochemical characterization.

Submicron injectable emulsions have been gaining more and more attention in the last few years, mainly as a vehicle for the intravenous administration of lipophilic drugs rather than as an improved delivery system for drug targeting. Submicron emulsions are available, clinically well accepted, and successfully marketed. Novel original emulsion formulations are being extensively investigated and already exhibit improved pharmacological activity; this fact underlines the promising therapeutic properties of these colloidal drug carriers as vehicles for potent lipophilic drugs. It is therefore essential to carry out a comprehensive physicochemical characterization of these submicron emulsions. It is the objective of the present review to emphasize the need for physicochemical studies in the design of new submicron emulsion drug delivery systems and to describe the different approaches available for carrying out such a complete examination of the emulsion colloidal drug carrier system.