Emulsion Problem Encountered in Extractions

Emulsion It may be defined as- a dispersed system containing at least two immiscible liquid phases . 

The effective and meaningful extraction of an analyte is rendered almost impossible when one encounters an emulsion formation during an extraction process thereby the separation of the two phases becomes difficult. Actually, it offers a frequent and serious problem when dealing with the extraction of drugs from biological as well as pharmaceutical formulations. 

Emulsion formation enhances the area of the interface between the two immiscible solvents and as a result also enhances the free energy of the system, which may be designated by the following expression  

A = change in surface area resulting from emulsification. 

Obviously the lowest free energy is given by the most stable state for a system at constant pressure and, therefore, in due course an emulsion shall break spontaneously to the two-layered system. However, the breaking of an emulsion could be relatively a rather slow phenomenon. There are a number of factors which may be responsible for the slow-coalescence of an emulsion, namely  

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