Olive oil nanoemulsion preparation using high-pressure homogenization and D-phase emulsification - A design space approach

Olive oil has been extensively applied in the pharmaceutical and cosmetic industries due to its biological properties. These are attributed to monounsaturated fatty acids like oleic acid and other minor components, such as phenolics and triterpenic acids. Oil-in-water nanoemulsion may enhance the solubility of poorly water-soluble drugs, which comprise about 40% of the currently marketed ones. However, the development of vegetable oil nanoemulsions is challenging due to their complex composition. In this study, olive oil nanoemulsions were prepared using high-pressure homogenization (HPH) and D-phase emulsification (DPE), as high- and low-energy processes, respectively. DPE has the potential to overcome the drawbacks of conventional Phase Inversion Methods. Aiming to achieve a deeper understanding of HPH and DPE processes, a design of experiment approach was successfully applied. This approach allowed identifying and understanding the relationship between input factors and their associated output response, at the stage of the nanoemulsion development. Moreover, in a specific range of critical process parameters and compositions, within the design space, nanoemulsions with similar mean particle sizes of 275 nm were achieved with equal composition, regardless of the use of the HPH or DPE process.