PHASE STUDIES AND PARTICLE-SIZE ANALYSIS OF OIL-IN-WATER PHOSPHOLIPIDMICROEMULSIONS

Phase studies were carried out on systems composed of commercial sampl es of egg and soya lecithin, ethanol, isopropyl myristate and water at different ethanol/water ratios. Stable oil-in-water microemulsion reg ions were identified. Static and dynamic light scattering (photon corr elation spectroscopy) techniques were used to determine the droplet si ze. Data were analysed using a hard sphere model to correct for interp article interactions. The droplet radius of the microemulsions was bet ween approx. 10 and 60 nm and increased with increasing volume fractio n of isopropyl myristate. The influence of the formulation on the drop let diameter has been examined.