DROPLET SIZE DISTRIBUTION WITHIN OIL-IN-WATER EMULSIONS PREPARED FROM SOLID-STATE DISPERSIONS

Emulsions (o/w) were prepared from solid state emulsions and the effects of time and composition on the droplet size and distribution were investigated. Results indicate that the interand intrabatch variability, based on the average particle size, is very small. The droplet distribution was found to initially be trimodal but proceeded to become unimodal after approximately 6 h. In addition to the size distribution becoming unimodal, the average droplet diameter decreased from 10 to 1.5 µm. The final droplet size appeared to be very stable as judged by equivalent droplet distributions observed post freeze/thaw and autoclaving treatments. The rate of the self-emulsifying process was found to be dependent on the relative ratio of matrix material to the oil phase. This investigation highlights our findings that oil-in-water emulsions can be prepared from solid state emulsions without the use of emulsifying agents. © 1993 Academic Press, Inc.