The present work attempted to apply the theoretical framework described by Taylor to different multiple emulsions under shear. The results were in relatively good agreement with the theory. The correlation between the fragmentation and release studies was well proved. Moreover, these studies showed that mechanisms taking place during the breakup were complex and did not always lead to a total release of the entrapped electrolyte. Some phenomena such as a partial leakage of the internal aqueous compartment or the expulsion of aqueous microglobules covered by a residual lipophilic film were able to restrict the release. Copyright 1999 Academic Press.