Colloidal emulsion based delivery systems for steroid glycosides

Abstract

Water insoluble bioactive molecules with limited solubility in common triglyceride are difficult to formulate in colloidal form. We demonstrate the fabrication and characterization of nanoscale diacylglycerol oil-in-water emulsions containing high levels (20 wt%) of steroid glycosides stabilized by food grade emulsifiers. The emulsions were produced using ultra high pressure (120 MPa) homogenization with average droplet sizes as small as 80 nm. The nanoscale emulsions were stabilized using food grade surfactants, surface active biopolymers and proteins. Due to amphiphilic nature of steroid glycosides molecule and higher polarity of the diacylglycerol rich oils used as solvents, it was possible to prepare stable emulsifier-free emulsions. The emulsions displayed very good stability against Ostwald ripening, creaming and coalescence. The emulsions were followed in time and were found stable for more than one year. In the presence of some sugars, the emulsions can be freeze-dried and form readily water dispersible powders without significant coalescence.

Keywords

• Colloids
• Emulsions
• Delivery
• Steroid glycosides
• Nanoemulsions