ABSTRACT
The spinning tube zetameter, an apparatus which was utilized up to now to keep a gas bubble from settling while electrophoretic measurement was carried out, can be used to measure the zeta potential of an oil drop as well. This piece of equipment is brought into play for estimating the influence of various formulation variables (pH, ionic strength, surfactant type or mixture) on the zeta potentials of oil drops. The results are compared to those reported in the literature.