A COMPARISON OF 2 QUALITY ASSESSMENT METHODS FOR EMULSIONS

A common method of assessing the quality of emulsions is to evaluate t he size distribution of the globules of the internal phase. The primar y aim of this work is to compare the sensitivity of this test to an al ternative method. The sizes of the globules of two emulsions, an oral emulsion and a total parenteral nutrition (TPN) emulsion, were determi ned using a light microscope. Globule size analyses were performed upo n preparation and during storage of the emulsions. Using a computer pr ogram specially developed for this study, the recorded diameters were placed into size groups and the volumes of each of the measured globul es was determined. For each size group, the total volume of all the gl obules within the group and the volume percentage of the oil phase rep resented by the group were calculated. The volume distribution of the internal phase across the size groups was found to predict emulsion in stability better than the globule number distribution and thus is a be tter determinant of emulsion quality. This technique may have general application in the evaluation or TPN emulsions and other spheres, such as liposomes.