7 th International Quality Conference May 24 th 2013 Center for Quality, Faculty of Engineering, University of Kragujevac 7 th IQC May, 24 2013 579 Pavle Mijovic 1) Evanthia Giagloglou 1) Branislav Jeremic 1) Ivan Macuzic 1) Marko Djapan 1) Marko Milosevic 1) 1) Faculty of Engineering, University of Kragujevac, Serbia {p.mijovic, eva.gia, bane, ivanm, djapan, m.milosevic}@kg.ac.rs INFLUENCE OF PROCESSING ON COSMETIC, PHARMACEUTICAL AND FOOD EMULSIONS QUALITY, STABILITY AND RHEOLOGY Abstract: Many pharmaceutical, cosmetic and food processes, such as new ingredient selections, formulation preparations, material packaging, and shelf storage are associated with a complex flow of materials. The application and acceptance of pharmaceuticals, cosmetic and food are also dependent on the flow properties of the final product. Therefore, rheological measurements, as an important route to revealing the flow and deformation behaviors of materials, cannot only improve efficiency in processing but can also help formulators and end users to find that these products are of optimal quality for their individual needs. Keywords: Emulsion stability, Quality, Rheology, Droplet Size Distribution 1. INTRODUCTION 1.1. Rheological Properties of emulsions Emulsions are the most common type of delivery system used in cosmetics and pharmacy. They enable a wide variety of ingredients to be quickly and conveniently delivered to hair, skin and internal use as well [1]. Further, they represent the basis for the many food products, such as ice cream, butter, margarine, mayonnaise, etc. Generally, emulsions can be defined as a thermodynamicaly unstable heterogeneous system formed by at least two liquids that are at best only slightly soluble [2]. The internal phase is dispersed in the other in the form of small droplets, with diameters higher than 0.1 m [3]. Emulsions can be made in different forms. The most common forms are oil-in-water (o/w), emulsions, which are composed of small droplets of oil dispersed in a continuous phase. The other type is water-in-oil (w/o) emulsion, which is composed of small droplets of water dispersed in a continuous oily phase. Emulsions can also be multiple emulsions, water-in-oil-in-water (w/o/w) emulsions. W/o/w, multiple emulsions are composed of oily globules dispersed in an aqueous phase, which themselves contain aqueous microglobules [4]. The rheology of emulsions is focusing a great interest mainly due to its relationship with emulsion stability, the most important factor to be considered in emulsion quality and technology. Thus, the huge numbers of structural parameters that influence emulsion stability also affect rheology, a fact that makes a systematic understanding of the complex rheological response of emulsions difficult. The flow properties of an emulsion are among its more important physical characteristics. From a technical point of view, the unit operations related to the manufacture of an emulsion (mixing, pumping, filling, etc.) require the knowledge of its flow behavior