Ethanol-in-oil emulsion (E/O) stabilized by polyglycerol polyricinoleate: A potential delivery system for ethanolic extract

ABSTRACT

This study evaluated how variations in polyglycerol polyricinoleate (PGPR) concentration and ethanol dispersed phase content affect the stability of ethanol-in-oil (E/O) emulsions. Results indicate that the stable 10 wt% E/O emulsions can be produced using 2 wt% PGPR. Increasing the ethanol dispersed phased content at constant PGPR concentration caused instability in emulsion. These emulsions remained stable to droplet flocculation and coalescence in the presence of Centella asiatica ethanol extract. PGPR does not greatly decrease the interfacial tension of the ethanol–oil interface. However, it adsorbed at the interface and stabilized the ethanol droplets in the emulsion via steric mechanism.

GRAPHICAL ABSTRACT

KEYWORDS:

• Delivery system
• ethanol-in-oil emulsion
• ethanolic extract
• polyglycerol polyricinoleate
• stability

Acknowledgments

Appreciation is expressed to Assoc. Prof. Parichat Hongsprabhas for her guidance and helpful advice in this work.