The influence of oleic acid on the formation of a spontaneous emulsion

Self-emulsifying drug delivery systems containing Tagat TO and ethyl oleate have been evaluated in the presence of low levels of oleic acid, a known c ontaminant of the component materials. Free oleic acid was removed with a c arbonate resin and the equilibrium particle size of the system determined a s the oleic acid was progressively added back to the system. No significant effect was observed until the level of free oleic acid in the Tagat TO had increased to 6% w/w. Beyond this level, the equilibrium particle size prog ressively increased. Results are discussed in terms of the dynamics of the oil/water interface during the emulsification process.