Micro-encapsulation by complex coacervation: influence of surfactant

Paraffin oil has been encapsulated using complex coacervation of gelatin and Arabic gum in the presence of a surfactant. Addition of an oppositely charged surfactant to a polyelectrolyte markedly increases the yield of the process. We report a two-layer encapsulation of paraffin oil, based on a primary layer of interface active polyelectrolyte-surfactant complex, followed by a second layer of the conjugate polyelectrolyte-polyelectrolyte complex. Surfactant concentration has been found to be a crucial parameter to obtain good quality microcapsules and optimal yield. This confirms the importance of formulation aspects when looking for optimization of these techniques of micro-encapsulation. (C) 2003 Society of Chemical Industry.