An efficient emulsification procedure for parenteral soybean oil‐in‐water, based on current know‐how on transitional inversion, was investigated. A fine droplet size lipid emulsion was produced using much lower mechanical energy than the typical industrial process. The aqueous phase was added gradually during mixing and various rates of water addition, as well as surfactant concentration, were evaluated. It was found that as addition rate and surfactant content increased, flow behavior changed significantly at intermediate water content, becoming highly viscoelastic. This behavior was related to the formation of a liquid crystalline phase that, at later mixing stages, turned into small droplets. Keywords: Formulation engineeringparenteral emulsionphase inversionrheological behavior We wish to thank the following institutions for founding this work: University of Los Andes Council for the Development of Science and Technology (CDCHT) under Grant I‐837‐05‐08‐A. Notes Part of the 1st International Conference on Industrial Processes for Nano and Micro Products, London, 2007.