Stability of multiple emulsions. I. Determination of factors influencing multiple drop breakdown

The paper describes a method to study the stability of w/o/w (water/oil/water) multiple drops by means of an ion-selective membrane-electrode, using a marker compound, ephedrine HCl. The effect of the 1st emulsifier concentration and the influence of the w/o emulsion ratio on the stability were investigated. An exponential equation and a power-function relationship were found to characterize the multiple drop breakdown during storage. The less the w/o emulsion ratio and the higher the 1st emulsifier concentration, the slower the multiple drop number decrease rate.