The emulsifying Properties of <i>Terminalia randii</i> baker F. Gum in castor oil and liquid paraffin emulsions

Abstract

Background: Emulsifying agents are added to preparations to facilitate the process of emulsification during manufacture and also to assure the stability of emulsion during the shelf life of the product. Natural gums have been used as emulsifying agents because they are readily available, non-toxic and cheap.
Objectives: In this study, the emulsifying properties of Terminalia randii gum were assessed and compared with a standard emulsifier (Tragacanth gum) using castor oil and liquid paraffin .
Method: Different concentrations (1-10% w/v) of the mucilages of Terminalia randii gum and Tragacanth were prepared. Using wet gum method, castor oil (fixed oil) was mixed with the mucilage and methyl paraben was added. Distilled water was used to make up to volume. The procedure was repeated for liquid paraffin (mineral oil). The emulsions were assessed using creaming rate, globule size and viscosity.
Results: Castor oil and liquid paraffin emulsions containing Terminalia gum did not show any form of creaming at high concentration (10% w/v). At low concentration (1-2% w/v), the emulsions cracked within 24 hours of preparation. There was no significance (p>0.05) difference in the globule sizes of emulsions containing Terminalia or tragacanth gum. The viscosity of emulsions containing Terminalia gum increased with increase in concentration of emulsifier and time. It was observed that after one week (168 hours) the viscosity of emulsions containing tragacanth started decreasing and this coincided with the time the emulsions started to cream or eventually cracked.
Conclusion: Terminalia randii gum produced more stable emulsions and thus could be used as alternative emulsifying agent.

Keywords: Terminalia randii gum, Emulsifying agent, Castor oil, Liquid Paraffin, Emulsions