Particle size and frequency of occurrence of particles of a certain size exert a significant influence on the properties of disperse systems. Therefore estimation of particle size of the internal phase is a suitable method for the evaluation of the quality of pharmaceutical emulsions. According to the particle size it is possible to evaluate the effect of the emulsifier and its concentration on the technological procedures and processing plant. Measurement of particle size by means of an optic microscope and statistical processing of results is facilitated by a computer programme, which considers the measured size of each individual particle from a defined selection.

        Key words: disperse systems – emulsion stability – particle size – microscopic analysis using a computer programme