The objective of this investigation was two-fold: to use capillary microscopy to assess instability in W1/O/W2 double emulsions and to explore the feasibility of using this type of system for targeted drug delivery. To better understand the role of surfactants in stability of water-in-oil-in-water (W1/O/W2) double emulsions, various types and concentrations of surfactants were employed in emulsion preparation. The use of capillary video microscopy enabled direct observation of the globules from the moment of their preparation. Information learned from these experiments is pertinent for better design of double emulsions for practical application. The use of surfactant in the external aqueous phase promoted external coalescence, that is the release of internal W1 droplets to the external W2 phase upon disruption of the oil/surfactant film separating the two aqueous phases. Variation of the concentration of surfactant in the outer W2 phase enabled control of the rate of release of the internal droplets; increasing its concentration led to a more rapid release The use of a functionalized phospholipid, N-glutaryl-phosphatidylethanolamine (NGPE), was explored to determine the benefits of its use in a W1/O/W 2 double-emulsion system for targeted drug delivery. Incorporating this molecule as a cosurfactant with Span 80 in the oil phase of a double-emulsion system resulted in a more prolonged release of the internal W1 droplets to the external phase through external coalescence. In drug-delivery applications, controlled and prolonged release is desirable for lessening toxic effects. Protein conjugation at the outer interface of oil-in-water droplets was then explored using quantitative fluorescence microscopy. There was no detected increase in the protein concentration of droplets immersed in a solution of monoclonal antibodies against a molecule with specificity for colonic cancer cells, CD44 variant 6. The use of NGPE in its activated form, however, did result in a significant increase in the protein concentration of droplets immersed in a solution of serum albumin proteins. The higher pH of the albumin buffer solution was a likely factor in the increased protein interactions. The use of NGPE in double-emulsion systems shows promise for combining prolonged release with targeting capabilities for use in drug-delivery applications