CHARACTERIZATION OF OIL-IN-WATER EMULSIONS PREPARED FROM SOLID-STATE EMULSIONS - EFFECT OF MATRIX AND OIL PHASE

Emulsions (o/w) were prepared from solid-state emulsions comprised of various matrix materials and oils and the resultant particle size prop erties determined. Results suggest that for those matrices that can fo rm solid-state emulsions, the droplet size decreased as a function of time, as previously observed. The final droplet size was dependent on the oil utilized but was independent of the matrix material. The use o f mineral oil resulted in the smallest droplet diameter (approximately 1.5 mum) while isopropyl myristate resulted in the largest droplet di ameter (approximately 3 mum). With the exception of mineral oil, the o il/water interfacial tension was found to be directly proportional to the droplet diameter. The rate of emulsification appeared to be biphas ic. The initial emulsification phase appeared to be independent of the matrix material while the terminal phase was a function of the matrix material. Most importantly, it was found that solid state emulsions c ould be prepared from a diverse, yet specific, list of matrices.