Learning Objective

• Stability problems encountered during the preparation of emulsions

An emulsion is a thermodynamically unstable preparation. So, care has to be taken to maintain the physical and chemical stability of the preparation throughout its shelf life. There should be no appreciable change in the mean particle size or the size distribution of the droplets of the dispersed phase. The droplets of the dispersed phase should remain uniformly distributed throughout the system.

Instabilities in emulsion can be grouped as follows:

1. Cracking
2. Creaming
3. Phase inversion