Preparation of Oil-in-Water Type Pickering Emulsions Stabilized by Partially Deacetylated Nanochitin and pH-triggered Drug Release

Abstract

Partially deacetylated nanochitin (DAcNC) exhibits amphiphilicity owing to the hydrophilic protonated amino groups and hydrophobic surface planes of DAcNC. Although DAcNCs possess emulsifying abilities, their role and versatility as emulsifiers remain unclear. In this study, we investigated oil-in-water (O/W) type Pickering emulsions stabilized with DAcNCs. Stable emulsions were formed using a variety of oils such as vegetable oils, decane, and ether oils. Measurements of the interfacial tension and adsorption of DAcNC showed that formation of tolerant interfacial films stabilized the emulsions. Furthermore, the pH-triggered release of ibuprofen, an antipyretic drug, was demonstrated using the emulsion. Enhanced ibuprofen release was observed upon increasing the pH from 2.0 to 6.0. This phenomenon can be attributed to the deprotonation of ammonium moieties on the DAcNC, which induced the desorption of DAcNC from oil/water interfaces. The DAcNC emulsion can be useful for the oral administration of ibuprofen as an antipyretic agent, facilitating intestinal release.