Study on preparation and formation mechanism of n-alkanol/water emulsion using alpha-cyclodextrin.

Abstract

Surfactants are usually used for the preparation of emulsions; however, some have an adverse effect on the human body such as skin irritation, hemolysis, and protein denaturation, etc. In this study, we examined the preparation and formation mechanism of n-alkanol/water emulsions using alpha-cyclodextrin (alpha-CD) as an emulsifier. Emulsions were prepared by mixing oil and water phases for 4 min at 2500 rpm using a vortex mixer. The mechanism of emulsification was investigated with some physico-chemical techniques. From phase diagrams of n-alkanol/alpha-CD/water systems, the emulsion phase extended as the chain length of n-alkanols and the amount of alpha-CD added increased. Furthermore, the emulsion was not formed in the region where the n-alkanol/alpha-CD complex didn't precipitate; however, the emulsion was formed in the region where the complex precipitated. In addition, it was clear that the emulsions have a yield stress value and correspond to the Maxwell model from rheological measurement. Our experiments clearly showed that the stable emulsions are formed because the precipitated complexes form a dense film at the oil-water interface and prevent aggregation among dispersed phases. Furthermore, it is suggested that the creation of a three-dimensional network structure formed by precipitated complexes in the continuous phase contributes to the stabilization of the emulsion. Thus, we concluded that the n-alkanol/water emulsions using alpha-cyclodextrin were a kind of the Pickering emulsion.

• Authors: Kaname Hashizaki, Takashi Kageyama, Motoki Inoue, Hiroyuki Taguchi, Haruhisa Ueda, Yoshihiro Saito
• Journal: Chemical & pharmaceutical bulletin (Chem Pharm Bull (Tokyo)) Vol. 55 Issue 11 Pg. 1620-5 (Nov 2007) ISSN: 0009-2363 [Print] Japan
• PMID: 17978523 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Alcohols
• Emulsifying Agents
• Oils
• alpha-Cyclodextrins
• Water

Topics

• Alcohols (chemistry)
• Chemistry, Pharmaceutical (methods)
• Emulsifying Agents (chemistry)
• Microscopy, Polarization
• Oils (chemistry)
• Rheology
• Solubility
• Stress, Mechanical
• Water (chemistry)
• X-Ray Diffraction
• alpha-Cyclodextrins (chemistry)